Electrical or fuel starting problem

[McBergs]

So recently bought an xj and putting quite a bit of work into it. Sometimes it just won’t start but not that often. Most of the time I just crank the wheel to the left while turning the key and then it starts, or I’ll just slowly turn it until it starts (important to note that it will cut out sometimes).

Today I wanted to see what happened if I just held the key and after about 5 seconds it just started. Not sure if turning the wheel even did anything before and it might have just been a coincidence that it started when I cranked it left. Read a post here that says something about the fuel pump check valve which seems to make sense, however I’m not sure if that’s consistent with the starter cutting out sometimes. Any help or advice is appreciated, thanks guys.

(Forum post https://www.jeepforum.com/forum/f11/...1500915/?amp=1 )

[RCP Phx]

What years and specs?

[McBergs]

Originally Posted by RCP Phx

What years and specs?

98 5 speed 4x4. Just did spark plugs and wires but nothing to fuel like the fuel pump and didn’t pressure test it.


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[Agreen]

Even if the check valve has gone bad it'll still start. It might run a little rough at first until fuel pressure comes up, but it'll start.
If it's just not starting (and intermittently) try replacing the CPS. It's a likely culprit, but I'm absolutely not saying it's the problem for sure. You have to catch it in a no-start condition and see if it's spark or fuel causing it to not start. There's a schrader valve on the fuel rail. You can depress the valve stem to see if there's pressure, but don't do it on a hot engine (since the exhaust is right below). If you're going to test spark, do so before checking fuel pressure. If you suspect injector pulse, use an LED light and not an incandescent test light.

[McBergs]

I’ll certainly look into it. Would that cause a code as well?


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[Agreen]

Maybe, maybe not. I don't know what parameters it looks for to set the CPS engine light. I work on many models, so it's hard to keep track of which one does specifically what. However, they're all (generally) the same idea. I've had CPS codes when the car had no other issue, and I've had cars not start due to a faulty CPS and not throw any codes. I've also had to diagnose random misfire codes when there was no discernable misfire. I do know, however, that the CPS is a particularly troublesome part on pretty much every 4.0 jeep, so given the symptoms it's a likely culprit.

[McBergs]

Originally Posted by Agreen

Maybe, maybe not. I don't know what parameters it looks for to set the CPS engine light. I work on many models, so it's hard to keep track of which one does specifically what. However, they're all (generally) the same idea. I've had CPS codes when the car had no other issue, and I've had cars not start due to a faulty CPS and not throw any codes. I've also had to diagnose random misfire codes when there was no discernable misfire. I do know, however, that the CPS is a particularly troublesome part on pretty much every 4.0 jeep, so given the symptoms it's a likely culprit.

That’s weird that a CPS would have anything to do with the position of the steering wheel, I’ll check with a multimeter as well when I look into it. Thanks for the help!


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[Agreen]

It doesn't. I'm guessing it's either a coincidence that turning the wheel helped or you may have bare wires touching the steering shaft.

When I worked for Dodge I had a Neon come to the shop because every time he turned left it would die. We could NOT reproduce the issue. Turns out the customer had driven the car until the gas was almost empty and was losing fuel pressure. I mean EMPTY. Then he filled up before bringing it to us. We all spent hours trying to diagnose the issue and eventually told him to call us when it happened again. We sent a tech out to him and that's when he saw the gas gauge was pegged low.

Regardless, check the wiring and see if something is chaffing.

[McBergs]

Well I found the problem, turns out I had to jam the clutch as hard as I could for it to start. Even if it was to the floor the safety switch wouldn’t make the connection, I had to literally stand on the clutch. Thanks for help anyways haha


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