95 ZJ Two symptoms, what's the problem?
1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained.
Driving from East Coast it stalled twice at idle. Driving into the Rocky Mountains have little power above 8000 feet. No check engine light, etc. Any thoughts? |
Re: 95 ZJ Two symptoms, what's the problem?
Howard did pass the time by typing:
> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. Just the basics. - spark (plugs, wires, cap, rotor, and possibly coil or distributor) - fuel (filter) High altitude will rob power. And you will feel a loss at 8000 ft but it shouldn't be too weak. When you go to altitude your better off using a lower octane fuel because the higher octane won't ignite as easily with the lower compression. Combine that with a weak spark and your going to go nowhere fast, except downhill in neutral that is. :) Cleaned the throttle body lately? http://members.cox.net/wilsond/tb/tb.html Not sure if the 95 can pull codes but cycle the key on-off-on-off-on (on, not start) then count the CHECK ENGINE light blinks, they come in pairs. i.e. BLINK ... BLINK BLINK is 12 http://members.cox.net/wilsond/engine_codes.html -- -- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors Banks Header - and BEER, in the fridge! |
Re: 95 ZJ Two symptoms, what's the problem?
Howard did pass the time by typing:
> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. Just the basics. - spark (plugs, wires, cap, rotor, and possibly coil or distributor) - fuel (filter) High altitude will rob power. And you will feel a loss at 8000 ft but it shouldn't be too weak. When you go to altitude your better off using a lower octane fuel because the higher octane won't ignite as easily with the lower compression. Combine that with a weak spark and your going to go nowhere fast, except downhill in neutral that is. :) Cleaned the throttle body lately? http://members.cox.net/wilsond/tb/tb.html Not sure if the 95 can pull codes but cycle the key on-off-on-off-on (on, not start) then count the CHECK ENGINE light blinks, they come in pairs. i.e. BLINK ... BLINK BLINK is 12 http://members.cox.net/wilsond/engine_codes.html -- -- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors Banks Header - and BEER, in the fridge! |
Re: 95 ZJ Two symptoms, what's the problem?
Howard did pass the time by typing:
> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. Just the basics. - spark (plugs, wires, cap, rotor, and possibly coil or distributor) - fuel (filter) High altitude will rob power. And you will feel a loss at 8000 ft but it shouldn't be too weak. When you go to altitude your better off using a lower octane fuel because the higher octane won't ignite as easily with the lower compression. Combine that with a weak spark and your going to go nowhere fast, except downhill in neutral that is. :) Cleaned the throttle body lately? http://members.cox.net/wilsond/tb/tb.html Not sure if the 95 can pull codes but cycle the key on-off-on-off-on (on, not start) then count the CHECK ENGINE light blinks, they come in pairs. i.e. BLINK ... BLINK BLINK is 12 http://members.cox.net/wilsond/engine_codes.html -- -- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors Banks Header - and BEER, in the fridge! |
Re: 95 ZJ Two symptoms, what's the problem?
On Wed, 8 Sep 2004 01:40:19 UTC nospamets@quadnet.net (Howard) wrote:
> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. > > Any thoughts? Bad gas, dirty air filter, go back to sea level. Seriously, at 8000 ft you will have lost over a third of your theoretical power (pushing 50% trying to top Vail Pass). I start at 6000+ and still notice the drop in power as I cross the Continental Divide - but having flown light aircraft in the mountains I'm a lot more aware of the effect than most people. Now consider the grades you are encountering and you can really feel it. Heck, I notice the difference when I drive down to the Texas coast and back up. After Raton Pass I fell like I should put my foot out and push going up hill. If you lived up here and replaced the CPS, the dealer would give you one that advances the base timing by several degrees. Given the stall at idle, it could also be either a bad TPS or (more commonly) a dirty connector on the TPS that was giving a bad reading at idle and/or WOT. Just to give you a better feel for the effect of altitude: light a/c, normally aspirated - even with fuel injection - pretty much reach their service ceiling at about 14000 or so. -- Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
On Wed, 8 Sep 2004 01:40:19 UTC nospamets@quadnet.net (Howard) wrote:
> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. > > Any thoughts? Bad gas, dirty air filter, go back to sea level. Seriously, at 8000 ft you will have lost over a third of your theoretical power (pushing 50% trying to top Vail Pass). I start at 6000+ and still notice the drop in power as I cross the Continental Divide - but having flown light aircraft in the mountains I'm a lot more aware of the effect than most people. Now consider the grades you are encountering and you can really feel it. Heck, I notice the difference when I drive down to the Texas coast and back up. After Raton Pass I fell like I should put my foot out and push going up hill. If you lived up here and replaced the CPS, the dealer would give you one that advances the base timing by several degrees. Given the stall at idle, it could also be either a bad TPS or (more commonly) a dirty connector on the TPS that was giving a bad reading at idle and/or WOT. Just to give you a better feel for the effect of altitude: light a/c, normally aspirated - even with fuel injection - pretty much reach their service ceiling at about 14000 or so. -- Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
On Wed, 8 Sep 2004 01:40:19 UTC nospamets@quadnet.net (Howard) wrote:
> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. > > Any thoughts? Bad gas, dirty air filter, go back to sea level. Seriously, at 8000 ft you will have lost over a third of your theoretical power (pushing 50% trying to top Vail Pass). I start at 6000+ and still notice the drop in power as I cross the Continental Divide - but having flown light aircraft in the mountains I'm a lot more aware of the effect than most people. Now consider the grades you are encountering and you can really feel it. Heck, I notice the difference when I drive down to the Texas coast and back up. After Raton Pass I fell like I should put my foot out and push going up hill. If you lived up here and replaced the CPS, the dealer would give you one that advances the base timing by several degrees. Given the stall at idle, it could also be either a bad TPS or (more commonly) a dirty connector on the TPS that was giving a bad reading at idle and/or WOT. Just to give you a better feel for the effect of altitude: light a/c, normally aspirated - even with fuel injection - pretty much reach their service ceiling at about 14000 or so. -- Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
Hi Will,
Back when I was serious drag racer in the sixties we bought engines cast for Colorado to gain a compression ratio running stock classes. This Cherokee build order eludes to the difference still in cars: "Emissions - High Altitude Tracking". Seats - Cloth Low-Back Bucket Luxury Group Trailer Tow Group IV Monotone Paint 4.7L Eng (EVA)/5Spd A/T 5-45Rfe(DGQ) Alternator - 136 Amp Battery - 625 Amp Maintenance Free Brakes - Anti-Lock 4-Wheel Disc Seats - Low Back Bucket Door Trim Panel - Highline Seat - Rear 60/40 Folding Air Bags - Side, Supplemental Child Seat Anchor System-LATCH Ready Air Bags-Front,Next Gen,Multistage** Air Bag-Side Window Curtain,Frt & Rr Carpet - Floor Carpet - Cargo Compartment Cargo Tie Down Loops Floor Mats - Front & Rear Cargo Trim Panel w/Storage Net Scuff Pads - Door Sill Cover - Cargo Compartment Assist Handles - Passenger Console - Mini Overhead Console - Full Length Floor Transmission - All 5-Speed Automatic Transmission-5-Spd Automatic 5-45RFE Torque Converter - Lock-Up Selec-Trac Full Time 4WD System Axle - Front, Dana 30/186MM Axle Ratio - 3.73 Axle - Rear, Dana 44/226MM Engine- 4.7L V8 MPI Windshield Glass - Tinted Glass - Front Door Tinted Glass - Deep Tint Sunscreen Glass - Flipper Liftgate Defroster - Rear Window Sun Visors - Illum Vanity Mirrors Mirror - Rear View, Auto Dim Mirrors - Power, Fold-Away Keyless Entry - Remote Sentry Key Theft Deterrent System Air Conditioning Insulation - Hood Insulation Group - Deluxe Route 24 - UP, Rolla, CO Instrument Cluster w/Tach Speedometer - 120 MPH Primary Windshield Wipers - Var Intermittent Wiper/Washer - Rear Window Horns - Electric, Dual Note Glove Box - Locking Power Outlet - Auxiliary 12V Power Accessory Delay Locks - Power Windows - Power, Driver One-Touch Seats -Power Front, Driver/Passenger STRIPE/BADGE/MOLDING/COLOR STRIPE/BADGE/MOLDING/COLOR Illuminated Entry Warning Chime Vehicle Information Center Lamps - Courtesy Lamp - Glove Box Lamp - Ash Tray Lamps - Rear Courtesy/Reading Lamp - Cargo Compartment Traveler/Mini Trip Computer Headlamps - Halogen Headlamps - Automatic Lamp - Center Hi-Mount Stop Security Alarm Bracket - Front License Plate Grille - Bright Windshield Moldings - Black Badge - Grand Cherokee, Bright Badge - Jeep, Bright Badge - V-8, Liftgate, Bright Roof Rack Badge - 4 X 4 Emissions - U.S. 50 State Emissions - High Altitude Tracking Low Emission Vehicle (LEV) Fuel Tank - 20.5 Gallon Cooler - Power Steering Speed Control Engine Cooling - Hydraulic Patriot Blue Pearl Coat Patriot Blue Pearl Coat All Radio Equipped Vehicles Radio-AM/FM Cass/CD/Equal/Chgr Ctrl Speaker System - Infinity Antenna - Fixed Audio Ctrls-Steering Wheel Mounted Steering - Power Rack and Pinion Steering Wheel - Leather Wrapped Suspension - Normal Duty Steering Column - Tilt Spare Tire - Inside Mount Spare Tire- Full Size, Matching Whl Tires - P245/70R16 OWL All Terrain Goodyear Brand Tires Wheels - 16 x 7.0 Lux Alum, Silver Wheels - All Aluminum Pedals - Power Adjustable Hitch - Class IV Receiver Wiring Harness - 7 Pin Adaptor - 7 to 4 Pin, Wiring Garage Door Opener - Universal Protective Coating and Remover Build To U S Market Specifications Manuf Statement of Origin 7 Additional Gallons Of Gas Spring - Left Front Spring - Left Rear Spring - Right Front Spring - Right Rear GVW/Payload Rating Four Wheel Drive (4WD)/(4X4) Left Hand Drive (LHD) God Bless America, ßill O|||||||O mailto:-------------------- http://www.----------.com/ Will Honea wrote: > > Bad gas, dirty air filter, go back to sea level. > > Seriously, at 8000 ft you will have lost over a third of your > theoretical power (pushing 50% trying to top Vail Pass). I start at > 6000+ and still notice the drop in power as I cross the Continental > Divide - but having flown light aircraft in the mountains I'm a lot > more aware of the effect than most people. Now consider the grades > you are encountering and you can really feel it. Heck, I notice the > difference when I drive down to the Texas coast and back up. After > Raton Pass I fell like I should put my foot out and push going up > hill. > > If you lived up here and replaced the CPS, the dealer would give you > one that advances the base timing by several degrees. Given the stall > at idle, it could also be either a bad TPS or (more commonly) a dirty > connector on the TPS that was giving a bad reading at idle and/or WOT. > > Just to give you a better feel for the effect of altitude: light a/c, > normally aspirated - even with fuel injection - pretty much reach > their service ceiling at about 14000 or so. > > -- > Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
Hi Will,
Back when I was serious drag racer in the sixties we bought engines cast for Colorado to gain a compression ratio running stock classes. This Cherokee build order eludes to the difference still in cars: "Emissions - High Altitude Tracking". Seats - Cloth Low-Back Bucket Luxury Group Trailer Tow Group IV Monotone Paint 4.7L Eng (EVA)/5Spd A/T 5-45Rfe(DGQ) Alternator - 136 Amp Battery - 625 Amp Maintenance Free Brakes - Anti-Lock 4-Wheel Disc Seats - Low Back Bucket Door Trim Panel - Highline Seat - Rear 60/40 Folding Air Bags - Side, Supplemental Child Seat Anchor System-LATCH Ready Air Bags-Front,Next Gen,Multistage** Air Bag-Side Window Curtain,Frt & Rr Carpet - Floor Carpet - Cargo Compartment Cargo Tie Down Loops Floor Mats - Front & Rear Cargo Trim Panel w/Storage Net Scuff Pads - Door Sill Cover - Cargo Compartment Assist Handles - Passenger Console - Mini Overhead Console - Full Length Floor Transmission - All 5-Speed Automatic Transmission-5-Spd Automatic 5-45RFE Torque Converter - Lock-Up Selec-Trac Full Time 4WD System Axle - Front, Dana 30/186MM Axle Ratio - 3.73 Axle - Rear, Dana 44/226MM Engine- 4.7L V8 MPI Windshield Glass - Tinted Glass - Front Door Tinted Glass - Deep Tint Sunscreen Glass - Flipper Liftgate Defroster - Rear Window Sun Visors - Illum Vanity Mirrors Mirror - Rear View, Auto Dim Mirrors - Power, Fold-Away Keyless Entry - Remote Sentry Key Theft Deterrent System Air Conditioning Insulation - Hood Insulation Group - Deluxe Route 24 - UP, Rolla, CO Instrument Cluster w/Tach Speedometer - 120 MPH Primary Windshield Wipers - Var Intermittent Wiper/Washer - Rear Window Horns - Electric, Dual Note Glove Box - Locking Power Outlet - Auxiliary 12V Power Accessory Delay Locks - Power Windows - Power, Driver One-Touch Seats -Power Front, Driver/Passenger STRIPE/BADGE/MOLDING/COLOR STRIPE/BADGE/MOLDING/COLOR Illuminated Entry Warning Chime Vehicle Information Center Lamps - Courtesy Lamp - Glove Box Lamp - Ash Tray Lamps - Rear Courtesy/Reading Lamp - Cargo Compartment Traveler/Mini Trip Computer Headlamps - Halogen Headlamps - Automatic Lamp - Center Hi-Mount Stop Security Alarm Bracket - Front License Plate Grille - Bright Windshield Moldings - Black Badge - Grand Cherokee, Bright Badge - Jeep, Bright Badge - V-8, Liftgate, Bright Roof Rack Badge - 4 X 4 Emissions - U.S. 50 State Emissions - High Altitude Tracking Low Emission Vehicle (LEV) Fuel Tank - 20.5 Gallon Cooler - Power Steering Speed Control Engine Cooling - Hydraulic Patriot Blue Pearl Coat Patriot Blue Pearl Coat All Radio Equipped Vehicles Radio-AM/FM Cass/CD/Equal/Chgr Ctrl Speaker System - Infinity Antenna - Fixed Audio Ctrls-Steering Wheel Mounted Steering - Power Rack and Pinion Steering Wheel - Leather Wrapped Suspension - Normal Duty Steering Column - Tilt Spare Tire - Inside Mount Spare Tire- Full Size, Matching Whl Tires - P245/70R16 OWL All Terrain Goodyear Brand Tires Wheels - 16 x 7.0 Lux Alum, Silver Wheels - All Aluminum Pedals - Power Adjustable Hitch - Class IV Receiver Wiring Harness - 7 Pin Adaptor - 7 to 4 Pin, Wiring Garage Door Opener - Universal Protective Coating and Remover Build To U S Market Specifications Manuf Statement of Origin 7 Additional Gallons Of Gas Spring - Left Front Spring - Left Rear Spring - Right Front Spring - Right Rear GVW/Payload Rating Four Wheel Drive (4WD)/(4X4) Left Hand Drive (LHD) God Bless America, ßill O|||||||O mailto:-------------------- http://www.----------.com/ Will Honea wrote: > > Bad gas, dirty air filter, go back to sea level. > > Seriously, at 8000 ft you will have lost over a third of your > theoretical power (pushing 50% trying to top Vail Pass). I start at > 6000+ and still notice the drop in power as I cross the Continental > Divide - but having flown light aircraft in the mountains I'm a lot > more aware of the effect than most people. Now consider the grades > you are encountering and you can really feel it. Heck, I notice the > difference when I drive down to the Texas coast and back up. After > Raton Pass I fell like I should put my foot out and push going up > hill. > > If you lived up here and replaced the CPS, the dealer would give you > one that advances the base timing by several degrees. Given the stall > at idle, it could also be either a bad TPS or (more commonly) a dirty > connector on the TPS that was giving a bad reading at idle and/or WOT. > > Just to give you a better feel for the effect of altitude: light a/c, > normally aspirated - even with fuel injection - pretty much reach > their service ceiling at about 14000 or so. > > -- > Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
Hi Will,
Back when I was serious drag racer in the sixties we bought engines cast for Colorado to gain a compression ratio running stock classes. This Cherokee build order eludes to the difference still in cars: "Emissions - High Altitude Tracking". Seats - Cloth Low-Back Bucket Luxury Group Trailer Tow Group IV Monotone Paint 4.7L Eng (EVA)/5Spd A/T 5-45Rfe(DGQ) Alternator - 136 Amp Battery - 625 Amp Maintenance Free Brakes - Anti-Lock 4-Wheel Disc Seats - Low Back Bucket Door Trim Panel - Highline Seat - Rear 60/40 Folding Air Bags - Side, Supplemental Child Seat Anchor System-LATCH Ready Air Bags-Front,Next Gen,Multistage** Air Bag-Side Window Curtain,Frt & Rr Carpet - Floor Carpet - Cargo Compartment Cargo Tie Down Loops Floor Mats - Front & Rear Cargo Trim Panel w/Storage Net Scuff Pads - Door Sill Cover - Cargo Compartment Assist Handles - Passenger Console - Mini Overhead Console - Full Length Floor Transmission - All 5-Speed Automatic Transmission-5-Spd Automatic 5-45RFE Torque Converter - Lock-Up Selec-Trac Full Time 4WD System Axle - Front, Dana 30/186MM Axle Ratio - 3.73 Axle - Rear, Dana 44/226MM Engine- 4.7L V8 MPI Windshield Glass - Tinted Glass - Front Door Tinted Glass - Deep Tint Sunscreen Glass - Flipper Liftgate Defroster - Rear Window Sun Visors - Illum Vanity Mirrors Mirror - Rear View, Auto Dim Mirrors - Power, Fold-Away Keyless Entry - Remote Sentry Key Theft Deterrent System Air Conditioning Insulation - Hood Insulation Group - Deluxe Route 24 - UP, Rolla, CO Instrument Cluster w/Tach Speedometer - 120 MPH Primary Windshield Wipers - Var Intermittent Wiper/Washer - Rear Window Horns - Electric, Dual Note Glove Box - Locking Power Outlet - Auxiliary 12V Power Accessory Delay Locks - Power Windows - Power, Driver One-Touch Seats -Power Front, Driver/Passenger STRIPE/BADGE/MOLDING/COLOR STRIPE/BADGE/MOLDING/COLOR Illuminated Entry Warning Chime Vehicle Information Center Lamps - Courtesy Lamp - Glove Box Lamp - Ash Tray Lamps - Rear Courtesy/Reading Lamp - Cargo Compartment Traveler/Mini Trip Computer Headlamps - Halogen Headlamps - Automatic Lamp - Center Hi-Mount Stop Security Alarm Bracket - Front License Plate Grille - Bright Windshield Moldings - Black Badge - Grand Cherokee, Bright Badge - Jeep, Bright Badge - V-8, Liftgate, Bright Roof Rack Badge - 4 X 4 Emissions - U.S. 50 State Emissions - High Altitude Tracking Low Emission Vehicle (LEV) Fuel Tank - 20.5 Gallon Cooler - Power Steering Speed Control Engine Cooling - Hydraulic Patriot Blue Pearl Coat Patriot Blue Pearl Coat All Radio Equipped Vehicles Radio-AM/FM Cass/CD/Equal/Chgr Ctrl Speaker System - Infinity Antenna - Fixed Audio Ctrls-Steering Wheel Mounted Steering - Power Rack and Pinion Steering Wheel - Leather Wrapped Suspension - Normal Duty Steering Column - Tilt Spare Tire - Inside Mount Spare Tire- Full Size, Matching Whl Tires - P245/70R16 OWL All Terrain Goodyear Brand Tires Wheels - 16 x 7.0 Lux Alum, Silver Wheels - All Aluminum Pedals - Power Adjustable Hitch - Class IV Receiver Wiring Harness - 7 Pin Adaptor - 7 to 4 Pin, Wiring Garage Door Opener - Universal Protective Coating and Remover Build To U S Market Specifications Manuf Statement of Origin 7 Additional Gallons Of Gas Spring - Left Front Spring - Left Rear Spring - Right Front Spring - Right Rear GVW/Payload Rating Four Wheel Drive (4WD)/(4X4) Left Hand Drive (LHD) God Bless America, ßill O|||||||O mailto:-------------------- http://www.----------.com/ Will Honea wrote: > > Bad gas, dirty air filter, go back to sea level. > > Seriously, at 8000 ft you will have lost over a third of your > theoretical power (pushing 50% trying to top Vail Pass). I start at > 6000+ and still notice the drop in power as I cross the Continental > Divide - but having flown light aircraft in the mountains I'm a lot > more aware of the effect than most people. Now consider the grades > you are encountering and you can really feel it. Heck, I notice the > difference when I drive down to the Texas coast and back up. After > Raton Pass I fell like I should put my foot out and push going up > hill. > > If you lived up here and replaced the CPS, the dealer would give you > one that advances the base timing by several degrees. Given the stall > at idle, it could also be either a bad TPS or (more commonly) a dirty > connector on the TPS that was giving a bad reading at idle and/or WOT. > > Just to give you a better feel for the effect of altitude: light a/c, > normally aspirated - even with fuel injection - pretty much reach > their service ceiling at about 14000 or so. > > -- > Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
A loss of power like every one is talking about is correct. What gas did you put in it? Colorado sells 85 octane (this is their "regular" gas), you might as well piss in the tank at altitude. It also could be the IAC too. --James "Howard" <nospamets@quadnet.net> wrote in message news:4337c03f.0409071740.23a4b79d@posting.google.c om... > 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. > > Any thoughts? |
Re: 95 ZJ Two symptoms, what's the problem?
A loss of power like every one is talking about is correct. What gas did you put in it? Colorado sells 85 octane (this is their "regular" gas), you might as well piss in the tank at altitude. It also could be the IAC too. --James "Howard" <nospamets@quadnet.net> wrote in message news:4337c03f.0409071740.23a4b79d@posting.google.c om... > 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. > > Any thoughts? |
Re: 95 ZJ Two symptoms, what's the problem?
A loss of power like every one is talking about is correct. What gas did you put in it? Colorado sells 85 octane (this is their "regular" gas), you might as well piss in the tank at altitude. It also could be the IAC too. --James "Howard" <nospamets@quadnet.net> wrote in message news:4337c03f.0409071740.23a4b79d@posting.google.c om... > 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. > Driving from East Coast it stalled twice at idle. Driving into the > Rocky Mountains have little power above 8000 feet. No check engine > light, etc. > > Any thoughts? |
Re: 95 ZJ Two symptoms, what's the problem?
At altitude, the engine does not need as much octane since the engine's
compression pressure at higher altitudes is not as high as it is at lower altitudes. This is WHY lower octanes are sold at higher altitudes. Jerry -- Jerry Bransford PP-ASEL N6TAY See the Geezer Jeep at http://members.cox.net/jerrypb/ "RocknTJ" <jetowle@cox.net> wrote in message news:E4x%c.284946$Oi.121760@fed1read04... > > A loss of power like every one is talking about is correct. > What gas did you put in it? Colorado sells 85 octane (this is their > "regular" gas), you might as well piss in the tank at altitude. > > It also could be the IAC too. > > --James > > "Howard" <nospamets@quadnet.net> wrote in message > news:4337c03f.0409071740.23a4b79d@posting.google.c om... >> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. >> Driving from East Coast it stalled twice at idle. Driving into the >> Rocky Mountains have little power above 8000 feet. No check engine >> light, etc. >> >> Any thoughts? > > |
Re: 95 ZJ Two symptoms, what's the problem?
At altitude, the engine does not need as much octane since the engine's
compression pressure at higher altitudes is not as high as it is at lower altitudes. This is WHY lower octanes are sold at higher altitudes. Jerry -- Jerry Bransford PP-ASEL N6TAY See the Geezer Jeep at http://members.cox.net/jerrypb/ "RocknTJ" <jetowle@cox.net> wrote in message news:E4x%c.284946$Oi.121760@fed1read04... > > A loss of power like every one is talking about is correct. > What gas did you put in it? Colorado sells 85 octane (this is their > "regular" gas), you might as well piss in the tank at altitude. > > It also could be the IAC too. > > --James > > "Howard" <nospamets@quadnet.net> wrote in message > news:4337c03f.0409071740.23a4b79d@posting.google.c om... >> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. >> Driving from East Coast it stalled twice at idle. Driving into the >> Rocky Mountains have little power above 8000 feet. No check engine >> light, etc. >> >> Any thoughts? > > |
Re: 95 ZJ Two symptoms, what's the problem?
At altitude, the engine does not need as much octane since the engine's
compression pressure at higher altitudes is not as high as it is at lower altitudes. This is WHY lower octanes are sold at higher altitudes. Jerry -- Jerry Bransford PP-ASEL N6TAY See the Geezer Jeep at http://members.cox.net/jerrypb/ "RocknTJ" <jetowle@cox.net> wrote in message news:E4x%c.284946$Oi.121760@fed1read04... > > A loss of power like every one is talking about is correct. > What gas did you put in it? Colorado sells 85 octane (this is their > "regular" gas), you might as well piss in the tank at altitude. > > It also could be the IAC too. > > --James > > "Howard" <nospamets@quadnet.net> wrote in message > news:4337c03f.0409071740.23a4b79d@posting.google.c om... >> 1995 ZJ with 4.0 and auto, about 120,000 miles, well maintained. >> Driving from East Coast it stalled twice at idle. Driving into the >> Rocky Mountains have little power above 8000 feet. No check engine >> light, etc. >> >> Any thoughts? > > |
Re: 95 ZJ Two symptoms, what's the problem?
On Wed, 8 Sep 2004 03:33:54 UTC L.W.(ßill) ------ III
<----------@cox.net> wrote: > Hi Will, > Back when I was serious drag racer in the sixties we bought engines > cast for Colorado to gain a compression ratio running stock classes. > This Cherokee build order eludes to the difference still in cars: > "Emissions - High Altitude Tracking". > I thought that on those the "High Altitude Tracking" was mostly the aneroid that adjusted the metering rod positions. I guess now (with computer control and FI) that the MAF or MAP sensors wind up doing most of the adjusting thru the computer. -- Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
On Wed, 8 Sep 2004 03:33:54 UTC L.W.(ßill) ------ III
<----------@cox.net> wrote: > Hi Will, > Back when I was serious drag racer in the sixties we bought engines > cast for Colorado to gain a compression ratio running stock classes. > This Cherokee build order eludes to the difference still in cars: > "Emissions - High Altitude Tracking". > I thought that on those the "High Altitude Tracking" was mostly the aneroid that adjusted the metering rod positions. I guess now (with computer control and FI) that the MAF or MAP sensors wind up doing most of the adjusting thru the computer. -- Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
On Wed, 8 Sep 2004 03:33:54 UTC L.W.(ßill) ------ III
<----------@cox.net> wrote: > Hi Will, > Back when I was serious drag racer in the sixties we bought engines > cast for Colorado to gain a compression ratio running stock classes. > This Cherokee build order eludes to the difference still in cars: > "Emissions - High Altitude Tracking". > I thought that on those the "High Altitude Tracking" was mostly the aneroid that adjusted the metering rod positions. I guess now (with computer control and FI) that the MAF or MAP sensors wind up doing most of the adjusting thru the computer. -- Will Honea |
Re: 95 ZJ Two symptoms, what's the problem?
Will Honea proclaimed:
> On Wed, 8 Sep 2004 03:33:54 UTC L.W.(ßill) ------ III > <----------@cox.net> wrote: > > >>Hi Will, >> Back when I was serious drag racer in the sixties we bought engines >>cast for Colorado to gain a compression ratio running stock classes. >>This Cherokee build order eludes to the difference still in cars: >>"Emissions - High Altitude Tracking". >> > > > I thought that on those the "High Altitude Tracking" was mostly the > aneroid that adjusted the metering rod positions. I guess now (with > computer control and FI) that the MAF or MAP sensors wind up doing > most of the adjusting thru the computer. > Dunno of any vehicle these days that comes with optional "Denver Heads" The OP has something wrong though. I get a power loss at high altitude such as crossing the Colorado rockies, Sonora Pass, etc but have never had the stalling, coughing, bucking etc. |
Re: 95 ZJ Two symptoms, what's the problem?
Will Honea proclaimed:
> On Wed, 8 Sep 2004 03:33:54 UTC L.W.(ßill) ------ III > <----------@cox.net> wrote: > > >>Hi Will, >> Back when I was serious drag racer in the sixties we bought engines >>cast for Colorado to gain a compression ratio running stock classes. >>This Cherokee build order eludes to the difference still in cars: >>"Emissions - High Altitude Tracking". >> > > > I thought that on those the "High Altitude Tracking" was mostly the > aneroid that adjusted the metering rod positions. I guess now (with > computer control and FI) that the MAF or MAP sensors wind up doing > most of the adjusting thru the computer. > Dunno of any vehicle these days that comes with optional "Denver Heads" The OP has something wrong though. I get a power loss at high altitude such as crossing the Colorado rockies, Sonora Pass, etc but have never had the stalling, coughing, bucking etc. |
Re: 95 ZJ Two symptoms, what's the problem?
Will Honea proclaimed:
> On Wed, 8 Sep 2004 03:33:54 UTC L.W.(ßill) ------ III > <----------@cox.net> wrote: > > >>Hi Will, >> Back when I was serious drag racer in the sixties we bought engines >>cast for Colorado to gain a compression ratio running stock classes. >>This Cherokee build order eludes to the difference still in cars: >>"Emissions - High Altitude Tracking". >> > > > I thought that on those the "High Altitude Tracking" was mostly the > aneroid that adjusted the metering rod positions. I guess now (with > computer control and FI) that the MAF or MAP sensors wind up doing > most of the adjusting thru the computer. > Dunno of any vehicle these days that comes with optional "Denver Heads" The OP has something wrong though. I get a power loss at high altitude such as crossing the Colorado rockies, Sonora Pass, etc but have never had the stalling, coughing, bucking etc. |
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