DocOrng XJ

Ok so here's the deal.. I don't normally ask questions but I been sick for like 9 days now and I cant think clearly. So I need some help Please.

Vehicle: 96 Jeep Cherokee 4.0HO Manual 160K ish miles
Issue: When I turn it over, it cranks but will not start and stay that way.

What I know / Symptoms:
Battery & starter is good, it turns over.
Fuel pump and fuel filter are good and gas is flowing.
If I spray starting fluid down it's throat it starts and runs until i stop spraying.

What I've done:
Double checked battery, alternator, starter, fuel pump, fuel filter, fuel lines.
I pulled the injectors and there is alot of black crud built up. When i turn it on and turn it over, the injector's don't spray. (Are they suppose to?)

What I am asking:
Besides the injectors, is there anything else I need to look at?
What other Symptoms or problems it could be?

Thanks guys

holycaveman

Cam position sensor then PCM

cruiser54

Sounds like low fuel pressure to me. Verify fuel pressure first.

Roler

Yep, you state " fuel pump and filter are good and gas is flowing", but you have a crank-not start issue with a fuel delivery issue (because that what your diagnostics so far suggest!): so you need to verify fuel pressure at the rails.

And how did that the injectors don't spray?

syncview

yeah.. no fuel spray
test the fuel pressure as mentioned by cruiser

Kalali

No one suggesting a bad CPS? Looks like a typical symptom of a faulty CPS (crankshaft) to me.

JMcIrvin

does it have spark? mine would fire on ether without spark. but the whole no spray at injectors... id do like suggested and test fuel pressure and then look for maybe a bad ground to injectors where they are all not firing. I've been hearing a lot about grounding issues on these jeeps. I'm new to jeeps but I'm having an injector issue of my own. mine is an 87 though, could be much different.

holycaveman

Looks like someone has some reporting back to do.

holycaveman

He has spark. And he has fuel pressure. But the bad ground (even though it's every other answer on this forum) is actually something to consider or rather wiring in general in my op.

Bad camshaft position sensor or pcm and ground/ wiring can cause a no spray condition from the injectors.

Turbo X_J

How much in psi? I must have missed where anyone so far has stated a spec.

holycaveman

He stated he had pressure. Actual psi matters little in this particular issue.

For instance even with 10 psi the injectors will spray. He stated there was no spray at all.

How much psi is applied when he dumps fuel down the carb and it runs? Again psi is irrelevant for this application.

cruiser54

Runs on starting fluid.

Turbo X_J

I'm confused, so actual fuel pressure matters or it doesn't?

cruiser54

Perhaps he has less than this arbitrary number of "10"?

It runs on starting fluid.

Not enough fuel pressure or injectors not firing.

cruiser54

Absolutely does matter.

Where the number "10" came from I have no idea.