99 TJ 2.5L with some issues. (try this again) 3rd try
 

So I just put my TJ back on the road 6 months ago. It had been
sitting in my back driveway for 2+ years.
there are a few things going on with it that i need opinions on.
#1) it has no power (i know it's a 2.5l, but my YJ 2.5l had way more
power)
#2) mileage sux, getting about 16mpg highway (i know it has the
aerodynamics of a mailbox on wheels, but still, should be 20-22)
#3) CEL light is going on with a evap system failure code. i clear
the code, but it comes back on, sometimes it goes off on it's own,
then back on at some point. fuel economy seems better when it goes
off on it's own, untill it comes back on. have replaced the gas cap
already.
#4) starts hard after it's been sitting for a while. i've read the
posts about check valves and filters and regulators, and it's
definetly acting like a loss of pressure, so now i have to figure out
if it's in the regulator or check valve or injectors.
#5) (this ones the biggest pain in my butt) between 2000 and 2100 rpm,
if it's under any kind of load, like a slight hill, and i try to
accelerate, the engine skips and bucks. feels like i'm running out of
gas or skipping 2 cylinders. as soon as it hits 2100 rpm,
everything's fine, if it's under 2000 rpm, everything's fine. it's
like a switch.

i havn't checked fuel pressures yet, i'm planning to get a guage
today and do some of those tests. but wanted to get some oppinions
first.

Re: 99 TJ 2.5L with some issues. (try this again) 3rd try
 

The first post even worked, LOL!

I would be unplugging and checking out the TPS with a multimeter set on
ohms to see if it has a dead spot in the throttle response and be
cleaning the connection while unplugged. A bad connection on the TPS
can cause strange things to happen.

I suppose it could be checked for voltage when live, but I don't know
the method for that engine.

Isn't there a TSB for a pinch or crack on the vent near the tank causing
a leak in the evap system on some?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Zenophryk wrote:
> So I just put my TJ back on the road 6 months ago. It had been
> sitting in my back driveway for 2+ years.
> there are a few things going on with it that i need opinions on.
> #1) it has no power (i know it's a 2.5l, but my YJ 2.5l had way more
> power)
> #2) mileage sux, getting about 16mpg highway (i know it has the
> aerodynamics of a mailbox on wheels, but still, should be 20-22)
> #3) CEL light is going on with a evap system failure code. i clear
> the code, but it comes back on, sometimes it goes off on it's own,
> then back on at some point. fuel economy seems better when it goes
> off on it's own, untill it comes back on. have replaced the gas cap
> already.
> #4) starts hard after it's been sitting for a while. i've read the
> posts about check valves and filters and regulators, and it's
> definetly acting like a loss of pressure, so now i have to figure out
> if it's in the regulator or check valve or injectors.
> #5) (this ones the biggest pain in my butt) between 2000 and 2100 rpm,
> if it's under any kind of load, like a slight hill, and i try to
> accelerate, the engine skips and bucks. feels like i'm running out of
> gas or skipping 2 cylinders. as soon as it hits 2100 rpm,
> everything's fine, if it's under 2000 rpm, everything's fine. it's
> like a switch.
>
> i havn't checked fuel pressures yet, i'm planning to get a guage
> today and do some of those tests. but wanted to get some oppinions
> first.
>

Re: 99 TJ 2.5L with some issues. (try this again) 3rd try
 

The first post even worked, LOL!

I would be unplugging and checking out the TPS with a multimeter set on
ohms to see if it has a dead spot in the throttle response and be
cleaning the connection while unplugged. A bad connection on the TPS
can cause strange things to happen.

I suppose it could be checked for voltage when live, but I don't know
the method for that engine.

Isn't there a TSB for a pinch or crack on the vent near the tank causing
a leak in the evap system on some?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Zenophryk wrote:
> So I just put my TJ back on the road 6 months ago. It had been
> sitting in my back driveway for 2+ years.
> there are a few things going on with it that i need opinions on.
> #1) it has no power (i know it's a 2.5l, but my YJ 2.5l had way more
> power)
> #2) mileage sux, getting about 16mpg highway (i know it has the
> aerodynamics of a mailbox on wheels, but still, should be 20-22)
> #3) CEL light is going on with a evap system failure code. i clear
> the code, but it comes back on, sometimes it goes off on it's own,
> then back on at some point. fuel economy seems better when it goes
> off on it's own, untill it comes back on. have replaced the gas cap
> already.
> #4) starts hard after it's been sitting for a while. i've read the
> posts about check valves and filters and regulators, and it's
> definetly acting like a loss of pressure, so now i have to figure out
> if it's in the regulator or check valve or injectors.
> #5) (this ones the biggest pain in my butt) between 2000 and 2100 rpm,
> if it's under any kind of load, like a slight hill, and i try to
> accelerate, the engine skips and bucks. feels like i'm running out of
> gas or skipping 2 cylinders. as soon as it hits 2100 rpm,
> everything's fine, if it's under 2000 rpm, everything's fine. it's
> like a switch.
>
> i havn't checked fuel pressures yet, i'm planning to get a guage
> today and do some of those tests. but wanted to get some oppinions
> first.
>

Re: 99 TJ 2.5L with some issues. (try this again) 3rd try
 

The first post even worked, LOL!

I would be unplugging and checking out the TPS with a multimeter set on
ohms to see if it has a dead spot in the throttle response and be
cleaning the connection while unplugged. A bad connection on the TPS
can cause strange things to happen.

I suppose it could be checked for voltage when live, but I don't know
the method for that engine.

Isn't there a TSB for a pinch or crack on the vent near the tank causing
a leak in the evap system on some?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Zenophryk wrote:
> So I just put my TJ back on the road 6 months ago. It had been
> sitting in my back driveway for 2+ years.
> there are a few things going on with it that i need opinions on.
> #1) it has no power (i know it's a 2.5l, but my YJ 2.5l had way more
> power)
> #2) mileage sux, getting about 16mpg highway (i know it has the
> aerodynamics of a mailbox on wheels, but still, should be 20-22)
> #3) CEL light is going on with a evap system failure code. i clear
> the code, but it comes back on, sometimes it goes off on it's own,
> then back on at some point. fuel economy seems better when it goes
> off on it's own, untill it comes back on. have replaced the gas cap
> already.
> #4) starts hard after it's been sitting for a while. i've read the
> posts about check valves and filters and regulators, and it's
> definetly acting like a loss of pressure, so now i have to figure out
> if it's in the regulator or check valve or injectors.
> #5) (this ones the biggest pain in my butt) between 2000 and 2100 rpm,
> if it's under any kind of load, like a slight hill, and i try to
> accelerate, the engine skips and bucks. feels like i'm running out of
> gas or skipping 2 cylinders. as soon as it hits 2100 rpm,
> everything's fine, if it's under 2000 rpm, everything's fine. it's
> like a switch.
>
> i havn't checked fuel pressures yet, i'm planning to get a guage
> today and do some of those tests. but wanted to get some oppinions
> first.
>

Re: 99 TJ 2.5L with some issues. (try this again) 3rd try
 

The first post even worked, LOL!

I would be unplugging and checking out the TPS with a multimeter set on
ohms to see if it has a dead spot in the throttle response and be
cleaning the connection while unplugged. A bad connection on the TPS
can cause strange things to happen.

I suppose it could be checked for voltage when live, but I don't know
the method for that engine.

Isn't there a TSB for a pinch or crack on the vent near the tank causing
a leak in the evap system on some?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Zenophryk wrote:
> So I just put my TJ back on the road 6 months ago. It had been
> sitting in my back driveway for 2+ years.
> there are a few things going on with it that i need opinions on.
> #1) it has no power (i know it's a 2.5l, but my YJ 2.5l had way more
> power)
> #2) mileage sux, getting about 16mpg highway (i know it has the
> aerodynamics of a mailbox on wheels, but still, should be 20-22)
> #3) CEL light is going on with a evap system failure code. i clear
> the code, but it comes back on, sometimes it goes off on it's own,
> then back on at some point. fuel economy seems better when it goes
> off on it's own, untill it comes back on. have replaced the gas cap
> already.
> #4) starts hard after it's been sitting for a while. i've read the
> posts about check valves and filters and regulators, and it's
> definetly acting like a loss of pressure, so now i have to figure out
> if it's in the regulator or check valve or injectors.
> #5) (this ones the biggest pain in my butt) between 2000 and 2100 rpm,
> if it's under any kind of load, like a slight hill, and i try to
> accelerate, the engine skips and bucks. feels like i'm running out of
> gas or skipping 2 cylinders. as soon as it hits 2100 rpm,
> everything's fine, if it's under 2000 rpm, everything's fine. it's
> like a switch.
>
> i havn't checked fuel pressures yet, i'm planning to get a guage
> today and do some of those tests. but wanted to get some oppinions
> first.
>