rdupuis

Hey guys,

My '88 Jeep Wrangler YJ has idling problems. It is fuel injected. It struggles when you stop at a red light or when you first start it up. It's like it wants to stall, and sometimes it does. It doesn't do it all the time though, but it does it often enough for me to not want to drive it.

Also, mostly when I'm driving through the city, I'll step on the gas to accellerate and it will hesitate and sputter before it gets going. I'll have to pop it into neutral and hit the gas to get the rpm's up.

I'm assuming the 2 problems are related, but I don't know for sure. Any ideas or advice would be greatly appreciated.

4x4 maniac

i had the exact same problem with my 92 yj it took me a while to figure it out but after checking the entire fuel system from back to front, i come to the conclusion that it is the fuel injector itself. so i bought some fuel injector cleaner put it straight in the gas tank according to the instuctions and it seemed to clear up the problem for a short time, after a few more applications of the product it has stoped the rough idleing and it also stopped the hesitation and sputtering, so all in all it is a injector problem, the cleaner provides a short term solution( for as long as you are using it) but the injector may have to be replaced if too badly worn

4x4 maniac

you may also want to try and change the oxygen sensor and the throtle positon sensor these two things should clear it right up the tps will stop the low idle speed therefore stop the cutting out when you slow down and the oxygen sensor may have a fault so to much gas (or not enough) is bein injected into the engine wich will make it splutter and hesitate

jeepyj_addict

you should check the fault codes. turn your key on then off 3 times in a row with no less than 3 seconds between... the check engine light will stay solid for a couple seconds before flashing a series of codes. code 33 you can ignore if you dont have AC, and code 55 is the last code that flashes telling you the check is done!

Mukwa

My bet is an Oxygen sensor. Had same with my XJ and it will happen same on almost any FI engines. MP or TB. You have to feather the throttle pedal to keep it going? You should change you oxygen sensor anually to get best performance. I bet you have poor fuel economy too?

jeepyj_addict

I take that back... pre 91 doesnt flash codes.... sorry!

1sickYJ

my vote is for the fuel injector as well... or the fuel filter hasnt been changed in a loong time

ZJdougy

Start with the basics, change fuel filter, and go from there. Oxygen sensor acting up is very possible. Running your engine lean (plugged fuel filter) will also take the sensor out after a while. O2 sensors are resilient, but not tough to take prolonged abuse. Coolant temp sensor can cause your engine to think its running in minus 300 degree temps, or 200' weather. This will cause fuel trim/level reads to be wayyy off as well. Best thing, change filter first, if that doesn't work.. have it scanned by someone with a scantool, ans watch the screen with them. If he doesn't allow you in the shop, ask for the scan code numbers. If he doesn't give you scan code numbers, he either didn't write them down, or he didn't scan it right.

Getting a diagnostic, is one way techs can scam you hardcore. ALWAYS ask what the code numbers were. Not only that, you can look them up online. Fuel pressure does not show up on this old of a ECM, so a faulty pump, or plugged filter will not show. A crappy cap/rotor can cause these problems as well... as with old plug wires. These little tidbits dont show up either on a scantool on the early units. GLuck

jeepmaster

it might be the problem of fuel injectors check the injectors and clean them and also check the oil filters and clear them time to time...................:):):):):)