My '94 4.0L Jeep didn't start this morning. Never a problem before...only 85k on it.

It cranked over like crazy but not even a cough or sputter. I checked the fuel rail, and fuel did squirt out so I know there is at least pressure.

So I was thinking spark. I did check some of the easy stuff, since I was dressed in work clothes.
I have 12.5 +/- volts at the coil wires with key on.
I have about 6.5-7 volts with key on while touching the HT side of the coil and ground.

I picked up a new cap and rotor at lunch, since it was the cheapest thing to start with and wouldn't be a waste of money. Plus I had a car act like this before and that was the problem.

Any other things I should try tonight when I get home? I'll try to get the wife out there and turn the engine over to check for spark if the new cap and rotor don't do it.

I have three Jeep Cherokees. Same motor and trans.

Question: Is it an automatic? Turn the key and nothing at all happens?

75% chance it's one of these:

Neutral Safety Switch (NSS) connector contacts need to be cleaned (reseat the connector).

OR

Crank Postion Sensor is going bad. In which case, for probably as much as 6 months and perhaps longer, reseating the connector for it will solve the problem. My step-son's XJ did this. We bought it really cheap 'cause I knew what was wrong with it. I had it towed from the sellers house to mine (AAA, free). Reseated the CPS connector, and it fired right up.

If you don't have a manual indicating the location of these connectors, let me know and I'll get you some pics.

I just re-read the crank and sputter part. Forget about the NSS and just go for the CPS connector.

Ahh, Ginter...that makes sense. To clarify, there was no sputter. Just turning over with starter.

I do have the Haynes and Chilton manual. I'll take a look at that tonight.

Thanks!!

Without looking at the manuals yet....how far do you have to tear in to the engine to replace the CPS? Looks like Napa has them for $61.99.

Changing the CPS is a bitch. It takes the right tools (common ones, wobble, long extension, etc...) and a lot of patience (I'm told). That's why my step-son is still running the same CPS after 7-8 months. I don't want to do it. I will eventually, but right now I have a 914/6 to restore (hopefully in 3 months). For now, just find the CPS, trace the harness and clean out the connectors with some brake or carb cleaner (insert electronic geeks best advice here), and reseat it a few times. Basically the terminals are too small to clean any other way. If the problem is the CPS, this may very well get you back on the road. I've know at least 5 other Jeep 4.0 owners that have had the same issue. It's a common failure.

EDIT:
Notice the obligatory 914 content. I realized that I hadn't answered the question. It's supposed to be accessible via a small cover in the block, hole near the starter in the bellhousing, something like that. I can't really remember since I have yet to perform the operation myself at this point. No major teardown, as long as you nimble and patient.

That must've been the 4X4 914 I saw goin' down the mountain the other day
bruce

Ignition module? Caused the same symptoms on my old Bronco. Woke up one day, and it just wouldn't start.

-Rusty

Rusty,
The CPS is located on top of the bell housing. You can best reach it from under the vehicle (drivers side) and it is removed and replaced with hand tools. It was not difficult, just awkward. The local Dealer had the best price when I replaced mine.
Suonds like alot of 914 people are also aflicted with Jeeps too. Must be in the genes.

I got rid of that Bronco long ago.

I've have a Wrangler for almost 3 years... never, ever had a problem or complaint with it. I'm very happy with my parts-chaser.

-Rusty

. . .yeah, and my Volvo 240 only starts sometimes. . . sometimes it doesn't. . .

Well, I looked at my manuals for the trouble codes (forgot about those things), that were in the Jeeps computer. One book says crankshaft position sensor no signal, the other book says camshaft position sensor or ignition sensor no signal.

Further reading of the manual, it appears to say, that you can lose camshaft signal and the car will run until you turn it off, then it won't start again. That sounds like what was happening.

Under the crankshaft, manual just says the car won't run. So I'm not sure if the car will continue to run until you shut it off....?

Anyways, I did the testing on both sensors....both of them seemed to fail .

Ginter, when you say to reseat the connector, I'm assuming you mean the electrical connector? Did that a few times, still no go.

Looks like a trip to NAPA for the crankshaft position sensor tomorrow.

my 93 4.0L jeep came with the "thief protection" key.
little black key taht sticks in a slot to the lower left of the steering column.

if the key fell out or you hit it with your knee (which happens frequently),
the car won't start. engine spins but no nothing.

just my 3 cents,
Andy

Yup. Sounds like you're on the right track.

Hey Ginter & Greg-

Got the Jeep running! Replaced the CPS and she started right up. Boy those bolts are tight!! It was a real excercise in patience.

Thanks again fellas.

Cool. Glad your rollin again.