I have a 89 xj with auto.New engine a few months ago and ran perfect until today.It started with longer starts this morning then at lunchtime it took longer than usuall to start.Anyways ,it sputtered and backfired at driving speeds in city starting off it sputters and backfires,but if i floor it it runs good but not the power it should but sounds good.Then i thought it was my fuel pressure reg so i replaced and still the problem is there,i drove it again and it keeps gradually getting worse,now it takes forever to start and stalls when idleing.It almost sounds like a real serious lobe,and wants to stall.Cant drive it because as soon as i touch the gas it sputters and backfires.I hear the fuel pump charging,no injector leakage externaly,new map,air charge,knock,and cooland sensers.Help me please...its my daily driver so need some wheels for work..
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Runs like a$$...
- Thread starter josh89xj
- Start date
5-90
NAXJA Forum User
- Location
- Hammerspace
Silly thought - check resistance of your TPS. Attach an ohmmeter (analogue is better for this) between terminals A & C or B & C, and run the throttle valve open and shut. Move it smoothly and slowly, and you should see a corresponding change in the resistance of the TPS - it should also be smooth and steady (it's OK to unplug it while you're doing this.)
If you've got a flat spot on the TPS wiper, it could cause a problem like you've got - I just went through that myself on my 88 this week-end.
Oh - if you've got the automatic transmission (AW4,) pull the 3-wire connector to access the TPS. The four-pole is for the Transmission Control Unit (TCU,) and will read differently (read: I'm not looking at that diagram while I'm writing this...)
5-90
If you've got a flat spot on the TPS wiper, it could cause a problem like you've got - I just went through that myself on my 88 this week-end.
Oh - if you've got the automatic transmission (AW4,) pull the 3-wire connector to access the TPS. The four-pole is for the Transmission Control Unit (TCU,) and will read differently (read: I'm not looking at that diagram while I'm writing this...)
5-90
Dr. Dyno
NAXJA Forum User
- Location
- Al Ain, UAE
Ditto on checking the fuel pressure when the engine's spluttering. I suspect the problem's the fuel pump.
ubstung71
NAXJA Forum User
- Location
- Colorado Springs, CO.
Exact situation and symptoms occurred on my '89 - turned out to be a bad fuel pump.
Bad fuel pump it was not,It was the hose on the fuel pump inside the tank .It somjehow came off the fitting that goes from the pump to the outlet INSIDE THE TANK????.Thats a first ive seen although it was a 20 min fix.Easiest fuel pump EVER! I just replaced the whole pump while i was in there,Runs like new again.If i can only get that damn temp guage issue fixed now...
http://www.naxja.org/forum/showthread.php?t=75742
http://www.naxja.org/forum/showthread.php?t=75742
