Turns over many times before starting
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
If the cap is new, doubtful that's your problem. The aluminum will just wear out much faster then the spendy brass one. Did you try the "key trick?" Just maybe that could be illuminating.
CF Veteran




Joined: May 2012
Posts: 7,965
Likes: 964
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
I just took the jeep on a camping trip. Put in 5 hours driving each way. On the way, I discovered an overheating issue. I thought maybe there was a problem with the cooling system. I was able to turn on the heater and keep the heat under control so I continued on our trip.
I found that when I stopped to fill up at the gas station, when I would unscrew my gas cap, a gush of pressure would be released sometimes. Quite a bit actually. I also found it hard to fill the tank back up as the pump would just trigger itself off every time I pulled the handle.
As we drove more and more, I noticed that I could not seem to get my speed above 65 (with 33s would have been close to 75) even with my foot to the floor. Also, at times when I was driving up long hills, I would have to put my foot to the floor just to maintain speed. Then the motor would heat up, I would have to turn the heater on to cool it to normal temps.
So, my theory is that my fuel pump is failing. That it cannot provide the fuel pressure needed at high speeds, which is causing my motor to run lean when I push it hard. If its running lean, its running hotter than usual.
Do I seem far off here?
I found that when I stopped to fill up at the gas station, when I would unscrew my gas cap, a gush of pressure would be released sometimes. Quite a bit actually. I also found it hard to fill the tank back up as the pump would just trigger itself off every time I pulled the handle.
As we drove more and more, I noticed that I could not seem to get my speed above 65 (with 33s would have been close to 75) even with my foot to the floor. Also, at times when I was driving up long hills, I would have to put my foot to the floor just to maintain speed. Then the motor would heat up, I would have to turn the heater on to cool it to normal temps.
So, my theory is that my fuel pump is failing. That it cannot provide the fuel pressure needed at high speeds, which is causing my motor to run lean when I push it hard. If its running lean, its running hotter than usual.
Do I seem far off here?
So, my theory is that my fuel pump is failing. That it cannot provide the fuel pressure needed at high speeds, which is causing my motor to run lean when I push it hard. If its running lean, its running hotter than usual.
i doubt that!!
Verified the issue to not be the fuel pump or filter. Going to get the exhaust fixed, new cat and muffler as per Cruiser54's recommendation. Probably will do the upgraded fuel injectors also.
I threw a timing light on it and turned it over. I dont think there is spark when the engine first turns over. It takes a second before spark starts. Its got new plugs, wires and distributor.
I threw a timing light on it and turned it over. I dont think there is spark when the engine first turns over. It takes a second before spark starts. Its got new plugs, wires and distributor.
The issue is not the cat either. Im back to square one. New cat, new fuel pump and fuel filter, new spark plugs, wires and distributor cap. No luck. It seems to be a delay in when the spark starts. Any other thoughts?
Last edited by NastyNinjaBEar; Apr 21, 2017 at 03:41 PM.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Ouch! That's allot of $ for no fix. Did you leave the tester hooked up for (5min) and see how fast the pressure dropped? Does the Poor man's prime work sometimes? Is it cranken pretty "briskly?" (Renix needs to see 300 RPM before spark happens)
Is it still ******* and overheating? (you should put your engine in your Sig) My 84 2.5 dogged pretty bad with a load on the highway, on hills anyway.
Is it still ******* and overheating? (you should put your engine in your Sig) My 84 2.5 dogged pretty bad with a load on the highway, on hills anyway.
I dont mind the cost, its just more parts of my jeep that I can be confident in for a while. The poor mans prime does not make any consistent difference. The starter is cranking exactly as you would expect it to.
I havent had a chance to test the overheating issue yet. It still refuses to accelerate past 65 ish at full throttle.
I havent had a chance to test the overheating issue yet. It still refuses to accelerate past 65 ish at full throttle.





