Political_Man
05-29-2007, 03:40 PM
I have a 1986 Jeep CJ-7 with an 4.0 l6 engine from a 1996 Jeep Grand Cherokee. Another piece of possible relevant information is that it has an after market fuel injection system installed. In fact it's quite the Frankenstein. I'm really more of a computer guy who's trying to learn more about cars and engines. I've fixed some other problems I've had with the Jeep on my own before (with some random advice from people) and I've had a lot of fun working on it but as I said I'm still trying to learn. Please excuse/correct any terminology errors on my part.
I'm having a couple of problems with my Jeep that I think may be related to a bigger problem of the engine randomly shutting down. The first problem is the idle speed. At first the idle was around 500 rpm, which seemed really low... in fact it seemed just barely enough to keep the engine running. Also driving down the road, the engine just randomly shuts down. The radio and interior lights, etc stay on like everything is normal electrically (although that's just an assumption on my part.) If (while still moving) I turn the key off and then back on again, the engine cuts back on and drives normal. Also what started to happen was that on start up the engine would start up but shut right back down again. It would take to or three times to start running normally. One other problem that seems as if it may be related. As time has gone on, after I turn the key the shutdown of the engine is delayed for a second or two. It seems like a normal shutdown but it's delayed by just enough to be noticed.
WHAT I DID:
There is a sensor at the front of the engine that detects the position of the fly wheel. I replaced that because I had a new one that came with the Jeep (still in the box) and I figured that since it wouldn't cost me anything to replace... that was as good a place to start as any. No noticeable difference.
There is a sensor on the throttle body assembly that as I understand it detects/controls the idle speed. After some adjustment that seemed to have fixed the idle speed at first. But now the idle fluctuates between being just right to being too high. At first during start up, it's definitely too high. But the engine seems to adjust to it after the first minute or so and runs normally for a little while... and then gets to be too high again.
Now I'm at a point where the engine seems to be shutting down more often on startup and going down the road.
I'm not sure what steps I should take next. Any advice offered would be greatly appreciated.
If there are any of you gearheads out there who live out in Carrolwood, who wouldn't mind hanging out, drinking some free beer, working on a classic Jeep, teaching a tech geek (and political super hero) a thing or two about cars and engines, and maybe earning a few bucks for your trouble, please e-mail me at politicalman@gmail.com .
Thanks in advance for any advice offered...
I'm having a couple of problems with my Jeep that I think may be related to a bigger problem of the engine randomly shutting down. The first problem is the idle speed. At first the idle was around 500 rpm, which seemed really low... in fact it seemed just barely enough to keep the engine running. Also driving down the road, the engine just randomly shuts down. The radio and interior lights, etc stay on like everything is normal electrically (although that's just an assumption on my part.) If (while still moving) I turn the key off and then back on again, the engine cuts back on and drives normal. Also what started to happen was that on start up the engine would start up but shut right back down again. It would take to or three times to start running normally. One other problem that seems as if it may be related. As time has gone on, after I turn the key the shutdown of the engine is delayed for a second or two. It seems like a normal shutdown but it's delayed by just enough to be noticed.
WHAT I DID:
There is a sensor at the front of the engine that detects the position of the fly wheel. I replaced that because I had a new one that came with the Jeep (still in the box) and I figured that since it wouldn't cost me anything to replace... that was as good a place to start as any. No noticeable difference.
There is a sensor on the throttle body assembly that as I understand it detects/controls the idle speed. After some adjustment that seemed to have fixed the idle speed at first. But now the idle fluctuates between being just right to being too high. At first during start up, it's definitely too high. But the engine seems to adjust to it after the first minute or so and runs normally for a little while... and then gets to be too high again.
Now I'm at a point where the engine seems to be shutting down more often on startup and going down the road.
I'm not sure what steps I should take next. Any advice offered would be greatly appreciated.
If there are any of you gearheads out there who live out in Carrolwood, who wouldn't mind hanging out, drinking some free beer, working on a classic Jeep, teaching a tech geek (and political super hero) a thing or two about cars and engines, and maybe earning a few bucks for your trouble, please e-mail me at politicalman@gmail.com .
Thanks in advance for any advice offered...