I have a 1990 YJ with 2.5 and TBI. IT has been rebuilt 2 years ago and has been my daily driver. Lately it has developed hard to start. I have changed fuel pump. fuel pump relays, fuel filter is new. coil and ignition module. and all engine sensors at rebuild. I have checked all grounds and connections. It also has developed a stumble when the throttle is held steady ant 50 MPH.
Starting issue
- Thread starter Eric Haberli
- Start date
Once in every 20 starts, the engine will not start, it will turn over for a long time with no start. Leave it sit for awhile and it will start. I have checked all the grounds connections, all in good shape. I rebuilt this jeep 2 years aga. The only sensor that I have not replaced is the PCM and ECM. Another question is how do you test for ECM faults when the 1990 had fault coed ports but I have had no luck finding a reader. There also is no check engine light to check coeds.
I wonder if Mark at wranglerfix has the ability to test these older units? Give him a call tomorrow and ask. Im guessing you have priced the ecm and were shocked lol.
redbullet
YJ Enthusiast
You mentioned you have a TBI. Wouldn’t happen to be Howell? I have a 4.2L with Howell. I get a similar condition every so often, 1 in 20 starts perhaps. After 5 seconds of grinding and no-start, I floor the pedal (while still cranking) and it starts within another 5 seconds reliably. The Howell computer (really a 1987 GM) is programmed to recognize when the pedal is floored and to stop feeding gas into the TBI. So maybe it’s flooding. Might give it a try.
sounds like my 91, my fix was exhaust leaks. check the torq on your exhaust manifold and look for cracks on the underneath side of the maifold
We'll I went to change out the battery and found the neg. post was loose? I hope this maybe the problem.
I always tell people start with the simple things first. You will be surprised how many times we over look the obvious. (Me all the time).