94 yj runs for ten minutes and then dies...

[collinma]

Hello everyone! I'm new to the board and can't wait to get started!

I saw a thread on here recently relating to a similiar problem but couln't find it.

My 94 YJ runs for ten minutes then doesn't for ten minutes then does... and so on and so on...

Any advice...

[Jeep_N_Hog]

Fuel pump and/or fuel filter?

[Texas4X4]

sounds like POS

[Jeepin Dave]

Welcome to the board!

To me it sounds like a Crank Position Sensor. I think there is a way to trouble shoot it too, but I cant seem to find a link. I am sure someone will though...

[Jeepin Dave]

Originally posted by Texas4X4:
sounds like POS POS????

I hope your not insulting another mans Jeep here.... :mad:

[Texas4X4]

lol...

Piece
Of
S***

just playin with ya man....the engines gone in my heep so you can ride that all day

[collinma]

i'll give the pos a try, hopefully that is it. Ive got a run comming up soon and would hate to be sitting bit@# in one of my buddies jeeps!

Thanks guys, I'll let you know how it goes.

[collinma]

i mean cps lol! and trust me, this jeep has been called worse!

[Jeep_N_Hog]

The crank position sensor is nothing more than a magnet that uses notches in the flywheel to keep ignition/fuel pulse timing.

When that goes out, your jeep quits, and won't start again. I've never heard of it working, and not, and working again. That is a signature bad fuel pump and/or filter symptom.

I don't think that the CPS is your problem. Last time I checked, they were running at about $80 a pop.

Let it run till it dies, leave the key in the on position and immediately pull the fuel line off at the fuel rail. Just watch your eyes. If there is pressure there, you'll know. If not, you found your problem.

If you've never replaced the fuel pump in that jeep, you're long over due. Same with the fuel filter.

If your filter is plugged up, the pump won't be able to push pressure past it. It'll take a while to fill the lines ahead of the fuel filter with fuel...enough to run the jeep for a few minutes. then take a few minutes to fill them up again.

I'd start with replacing the fuel filter. It's fairly cheap, and super easy to do. When you buy the filter, pick up some flexible rubber fuel line also, about 8 inches for each side of the filter...TWO DIFFERENT SIZES too so use the filter to make sure you get the right size.

Those short sections of fuel line have to make sharp bends and are in a pretty harsh environment under the jeep. They dry rot, as well as collapse in the area of the bend.

HTH

[Jeepin Dave]

Sorry Jeep N Hog, but I do not tend to agree with you.

I have a 95 Grand Cherokee with a V8 sitting in my driveway with a CPS issue. Its symptoms are straight forward. The motor runs for about 10-15 minutes, till it warms up and than shuts down. Like clockwork. The motor that I am putting it in the Jeep is from a Dodge Ram, and that too had the same problem a while back.

Here is link... Clicky-Clicky (http://bbb.quadratec.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=38;t=007717#000007)

and another...
Clicky- Clicky (http://bbb.quadratec.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=38;t=007720#000002)

I am not saying this is the issue with Collinma's Jeep, just that those symptoms are identical to the ones I had....

[Jeep_N_Hog]

quick way to check for the CPS on a 94 YJ is after a "no start". Turn the key to the on position, (not start), back off, then on, then off then on. Leave it in the on position, and count the number of times the "check engine" light blinks. It'll blink in 2 digit formats. 3 times, short pause, 2 times, is a "32".

If the Computer is not getting a signal from the CPS upon start up, it'll register a trouble code.

[Jeepin Dave]

Good Call! My ZJ was not pulling a code unless it happened like 3-4 consecutive times. Than it would register a code.

[edudley]

I agree with fuel filter first. Definately the CPS can be intermitent. We had an early 90s YJ do that this past weekend on the trail. it turned out to be the CPS connector. I have had a couple cars fail this way. The fuel pump could be the culprit. When it quits find the relief port on the fuel rail and see if there is any pressure in it. If there is its probably not fuel related.

[Theta163]

I think it sounds like a fuel pump issue.. If the CPS was intermitent as eduduley said it could be that.. But I would think that the CPS would prevent start up completely... :-/

[in2deep]

jeepin dave you are right on with the cpu going bad graemlins/49.gif