Hesitation during acceleration
 

I have a 89 Wrangler Laredo that I recently purchased. I've been going
through all of the normal tuneup steps (new plugs, plug wires, cap,
rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
Jeep ready to be a daily driver. Had the timing adjusted yesterday
(was getting rough idle to the point of stalling and severe pinging
during acceleration) and new issue came up. After about 20 minutes of
driving the Jeep would hesitate and "stumble" during hard
acceleration. I first noticed it going up a slight incline on the
freeway, then fairly consistently on surface streets. The engine never
stalled, but sounded like it needed more gas. I am thinking this is a
carb tuning issue. I am new to Jeeps and trying to learn more, but any
suggestions would be much appreciated.

Re: Hesitation during acceleration
 

You might go with your hunch and replace the fuel pump and filter.
You retarded your timing for the gasoline you are using, which
probably also took any horse power you had.
These are very good sites for the carburated YJs:
http://home.sprynet.com/~dale02/list.htm and,
http://www.off-road.com/jeep/yj-1-4-faq.html
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Ethan wrote:
>
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Re: Hesitation during acceleration
 

You might go with your hunch and replace the fuel pump and filter.
You retarded your timing for the gasoline you are using, which
probably also took any horse power you had.
These are very good sites for the carburated YJs:
http://home.sprynet.com/~dale02/list.htm and,
http://www.off-road.com/jeep/yj-1-4-faq.html
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Ethan wrote:
>
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Re: Hesitation during acceleration
 

You might go with your hunch and replace the fuel pump and filter.
You retarded your timing for the gasoline you are using, which
probably also took any horse power you had.
These are very good sites for the carburated YJs:
http://home.sprynet.com/~dale02/list.htm and,
http://www.off-road.com/jeep/yj-1-4-faq.html
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Ethan wrote:
>
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Re: Hesitation during acceleration
 

ethanjones@gmail.com (Ethan) wrote in message news:<31b69f22.0408311217.1bd9f056@posting.google. com>...
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Might want to check out the accelerator pump on the carb to make sure
it's working properly. With the engine off and the air cleaner
removed, you can open and close the throttle while looking inside the
air horns. Each time the throttle is opened a fairly good stream of
gas should squirt out.

If the stream is weak when you quickly open the throttle, check the
linkage rod that connects the throttle to the pump and make sure it
isn't bent. You can verify that the pump is the problem by trying to
slowly accelerate, if no stumble then it's likely the acceleration
pump. There might be a section in the service manual that explains
how to adjust or check the adjustment of the linkage rod and that's
where I'd start.

I agree that changing the filter would be a good idea (didn't you
already do that), but would check out the carb first before going to
the expense of replacing the fuel pump.

Good luck!
John

Re: Hesitation during acceleration
 

ethanjones@gmail.com (Ethan) wrote in message news:<31b69f22.0408311217.1bd9f056@posting.google. com>...
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Might want to check out the accelerator pump on the carb to make sure
it's working properly. With the engine off and the air cleaner
removed, you can open and close the throttle while looking inside the
air horns. Each time the throttle is opened a fairly good stream of
gas should squirt out.

If the stream is weak when you quickly open the throttle, check the
linkage rod that connects the throttle to the pump and make sure it
isn't bent. You can verify that the pump is the problem by trying to
slowly accelerate, if no stumble then it's likely the acceleration
pump. There might be a section in the service manual that explains
how to adjust or check the adjustment of the linkage rod and that's
where I'd start.

I agree that changing the filter would be a good idea (didn't you
already do that), but would check out the carb first before going to
the expense of replacing the fuel pump.

Good luck!
John

Re: Hesitation during acceleration
 

ethanjones@gmail.com (Ethan) wrote in message news:<31b69f22.0408311217.1bd9f056@posting.google. com>...
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Might want to check out the accelerator pump on the carb to make sure
it's working properly. With the engine off and the air cleaner
removed, you can open and close the throttle while looking inside the
air horns. Each time the throttle is opened a fairly good stream of
gas should squirt out.

If the stream is weak when you quickly open the throttle, check the
linkage rod that connects the throttle to the pump and make sure it
isn't bent. You can verify that the pump is the problem by trying to
slowly accelerate, if no stumble then it's likely the acceleration
pump. There might be a section in the service manual that explains
how to adjust or check the adjustment of the linkage rod and that's
where I'd start.

I agree that changing the filter would be a good idea (didn't you
already do that), but would check out the carb first before going to
the expense of replacing the fuel pump.

Good luck!
John

Re: Hesitation during acceleration
 

You could be easily describing a dirty air filter on the gas tank vent.
When plugged it puts a vacuum on the gas tank causing the symptoms you
describe. If it gets really bad, it will even act like it runs out of
gas.

The filter is about two bucks and is on the bottom of the charcoal
canister 'way' down under the brake booster. To test, drive with the
gas cap loose or unplug the very top hose on the carb float bowl to see
what happens.

Also a rebuild kit for that carb is in the twenty dollar range and is a
good thing to do now and then. The manual says with every plug change.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Ethan wrote:
>
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Re: Hesitation during acceleration
 

You could be easily describing a dirty air filter on the gas tank vent.
When plugged it puts a vacuum on the gas tank causing the symptoms you
describe. If it gets really bad, it will even act like it runs out of
gas.

The filter is about two bucks and is on the bottom of the charcoal
canister 'way' down under the brake booster. To test, drive with the
gas cap loose or unplug the very top hose on the carb float bowl to see
what happens.

Also a rebuild kit for that carb is in the twenty dollar range and is a
good thing to do now and then. The manual says with every plug change.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Ethan wrote:
>
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.

Re: Hesitation during acceleration
 

You could be easily describing a dirty air filter on the gas tank vent.
When plugged it puts a vacuum on the gas tank causing the symptoms you
describe. If it gets really bad, it will even act like it runs out of
gas.

The filter is about two bucks and is on the bottom of the charcoal
canister 'way' down under the brake booster. To test, drive with the
gas cap loose or unplug the very top hose on the carb float bowl to see
what happens.

Also a rebuild kit for that carb is in the twenty dollar range and is a
good thing to do now and then. The manual says with every plug change.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Ethan wrote:
>
> I have a 89 Wrangler Laredo that I recently purchased. I've been going
> through all of the normal tuneup steps (new plugs, plug wires, cap,
> rotor, fuel filter, timing, vacuum tube, etc.) in order to get the
> Jeep ready to be a daily driver. Had the timing adjusted yesterday
> (was getting rough idle to the point of stalling and severe pinging
> during acceleration) and new issue came up. After about 20 minutes of
> driving the Jeep would hesitate and "stumble" during hard
> acceleration. I first noticed it going up a slight incline on the
> freeway, then fairly consistently on surface streets. The engine never
> stalled, but sounded like it needed more gas. I am thinking this is a
> carb tuning issue. I am new to Jeeps and trying to learn more, but any
> suggestions would be much appreciated.