Dale Aeppli 1989 GW Surging Problem

[dduncan]

Dale,
I have a 1989 jeep Grand Waggoneer. The other day when I slowed down to make a turn the enging started surging. When I pressed the gas pedal the jeep would start forward and then bog right down like there was no gas. If I pressed the pedal down hard it would go but then if I let up the engine would almost die at times. Also I noticed that crusing at about 70 mph with steady gas pedal the engine would bog down then surge, then bog down then surge. I had to hold the pedal almost to the floor to keep it going. Then all of a sudden it returned to normal. It almost seemed like the gas was cutting in and out. I changed the fuel filter, put in new wires, plugs, rotar. It seemed better for about half an hour then the problem returned. It has run fine up until now. It runs just a little rough because the compression is a little low in one of the cylinders but it has always run ok.

Hope you can help me.
P.S. Changed the fuel pump about 3 months ago.

Dave

[Dale Aeppli]

Originally Posted by dduncan

Dale,
I have a 1989 jeep Grand Waggoneer. The other day when I slowed down to make a turn the enging started surging. When I pressed the gas pedal the jeep would start forward and then bog right down like there was no gas. If I pressed the pedal down hard it would go but then if I let up the engine would almost die at times. Also I noticed that crusing at about 70 mph with steady gas pedal the engine would bog down then surge, then bog down then surge. I had to hold the pedal almost to the floor to keep it going. Then all of a sudden it returned to normal. It almost seemed like the gas was cutting in and out. I changed the fuel filter, put in new wires, plugs, rotar. It seemed better for about half an hour then the problem returned. It has run fine up until now. It runs just a little rough because the compression is a little low in one of the cylinders but it has always run ok.

Hope you can help me.
P.S. Changed the fuel pump about 3 months ago.

Dave

hi have you had the fuel pressure checked with gauge when you changed the fuelpump & the filter did you use new hoses . check the short pieces of hose on the fuel filter & replace them. the same with the hoses on fuel tank possible that they sofftened or possible cracks causing air to get in line dale [email protected]
email me direct can't send thru forum

[Dsilver]

Dale is the man!!!

[dduncan002]

[Dsilver]

He can never be wrong, no matter what the problem, he knows the answer.

[bhowell]

Hi, I have a 1998 GC 5.2l that surges and bogs until it almost dies. The check engine light came on and it said that the o2 sensor is bad. Is this possibly the answer? $100 for a sensor is acceptable if thats the answer. I don't want to leave a money trail. Thanks

[Dale Aeppli]

Originally Posted by bhowell

Hi, I have a 1998 GC 5.2l that surges and bogs until it almost dies. The check engine light came on and it said that the o2 sensor is bad. Is this possibly the answer? $100 for a sensor is acceptable if thats the answer. I don't want to leave a money trail. Thanks

HI ITS POSSIBLE BEING THEY PULLED THE CODE PRICE ABOUT AVERAGE HPOPE THIS IS OF HELP [email protected]

[superzoe98]

Originally Posted by Dale Aeppli

HI ITS POSSIBLE BEING THEY PULLED THE CODE PRICE ABOUT AVERAGE HPOPE THIS IS OF HELP [email protected]

I have the same problem with my 97 JGC laredo. It was shimmying, idling rough, bucking sometimes worse than others. The check engine light came on, the codes indicated a problem with the O2 sensor and the mechanic subsequently discovered a crack in the exhaust manifold. The manifold and the sensor were replaced (not cheaply, I might add-he quoted the o2 sensor for $200 with labor alone). BUT problem seemed to be fixed.

NOW however, the shimmying has returned and the RPM's bounce slightly when idling. It stalled once on me in the morning when backing up and tried to stall when parallel parking. The mechanic asked what type of fuel I was using. I had recently started using 89 instead of 87 octane because it was pinging, but he's saying the lower octane is optimal and that the computer cannot be reprogrammed unless it's running the lowest octane. Any chance he's right and this is just a fuel octane problem? I'm sceptical that it's a full solution.

[Dale Aeppli]

Originally Posted by superzoe98

I have the same problem with my 97 JGC laredo. It was shimmying, idling rough, bucking sometimes worse than others. The check engine light came on, the codes indicated a problem with the O2 sensor and the mechanic subsequently discovered a crack in the exhaust manifold. The manifold and the sensor were replaced (not cheaply, I might add-he quoted the o2 sensor for $200 with labor alone). BUT problem seemed to be fixed.

NOW however, the shimmying has returned and the RPM's bounce slightly when idling. It stalled once on me in the morning when backing up and tried to stall when parallel parking. The mechanic asked what type of fuel I was using. I had recently started using 89 instead of 87 octane because it was pinging, but he's saying the lower octane is optimal and that the computer cannot be reprogrammed unless it's running the lowest octane. Any chance he's right and this is just a fuel octane problem? I'm sceptical that it's a full solution.

HI $ 200 is pretty stiff to cange a 02 sensor there is a slot inside the top section of throttle bore, on your throttlebody remove the air hose you will see the slot inthe throttlebody this is the air idle control valve. you ca get a spraycan of carb cleaner use the little straw that comes on can start hold on high idle spray into the slot spray it good the more the better clean it out good, if you have questions give a holler at [email protected] DALE

[bhowell]

Originally Posted by Dale Aeppli

HI ITS POSSIBLE BEING THEY PULLED THE CODE PRICE ABOUT AVERAGE HPOPE THIS IS OF HELP [email protected]

Hi again. I replaced both o2 sensors and this seemed to clear up the problem for awhile. It is back to surging and the CEL seems to come on more frequently. Just the other day I stopped at autozone to check the code and he read that it was o2 sensor bank one. As I mentioned I replaced both sensors. What else could it be? thanks for you help. bob