iamaskier87

1997 cherokee, 2.5 4 cylinder, ax5, 2wd, 122k miles

jeep has been running great. started up this morning, got half a mile down the road and it died. would not restart.

towed home. i can hear the fuel pump cycle when the key is turned. the starter turns the engine over. it doesn't sound like the engine is firing, just turning.

there is no schrader valve on the fuel rail to test.
spark plugs were replaced 5k miles ago.

whether or not it's related, prior to today it seemed like when the engine was cold it would take a second or two for the car to fire up. after the engine was hot, i would barely have to bump the starter and it would fire up.

wondering where to go next, thanks!

Sno_Blynd

sounds like an o2 sensor to me

Cherockee

have to verify that you have fuel, maybe pull an injector leave it plugged in and have someone crank the engine. maybe before you do that though check that you have power to the ignition coil.

Diesel

No it doesnt.

Check for fuel and spark

Rock Toy

x2 Diesel
When a rig quits running or turns over and will not start the first thing is always check for fuel and spark.

Narbu

i had the same problem on my jeep were i drow down the drive way and it died so after a lot of testing and digging around it ended up being the ASD relay, go in your fuse box under the hood find it and go buy a new one they are cheap so if it dont work its not like your out a bunch of money o and you might need a ingiton switch fuse also

Cherockee

At first I thought this too, but then I re-read his post and he said he can hear the fuel pump running, so it really can't be the ASD (it kills both fuel and spark). If you do want to test the relay though you don't even have to buy another one, just put a jumper wire in it.

Let's verify that there is power to the coil first, then spark at the plugs, then fuel to the injectors. Then after all that is verified, open the oil fill cap and watch the rockers as someone cranks over the engine to make sure there isn't something major wrong- timing would be the next place to look.

iamaskier87

crank position sensor?

Bustedback

A bad O2 sensor will not kill the engine unless the wires are grounded and the pcm fuse blows, very unlikely though.

iamaskier87

here's a summary after what i accomplished tonight:

jeep died while driving, will not restart. cranks but isn't firing.
i can hear the fuel pump run when the key is inserted.
all gauges on the dash are working.
tested crank position sensor, it's still good.
pulled a spark plug and cranked engine, not getting spark.
pulled the wire that feeds the ignition coil and tested it while key is in run position. READS NOTHING.

... where to go from here?

Diesel

Dont replace the coil, start with a basic tune up, or check the distributor for current.

Cherockee

okay, let's verify a couple things next. First, there is a two pin plug that plugs into the coil, one pin will have power with the ignition key on the other will not. Did you check them both?

If you dont have power in this two pin plug then double check the maix fuses in the fuse panel under the hood (passenger shock tower area) I think the first two are Ing/Run/Start. I all the fuese have power on both sides with the key on then look at the ASD relay- it's in the same panel as the maxi fuses are- the fues cover should tell you which one is the ASD relay. You could swap a relay from a non-required relay (like head lights or fog lights) and put it in place of the ASD relay. Try starting. If it still doesn't work then this is going to get harder for me to explain since I don't have my wiring diagrams in front of me. When I had a no start issue with my '99 I found that the ECM wasnt giving a signal to this ASD relay and therefore I got no power to my ignition coil. By tracing the wires I applied a gound to the correct pin of the ASD socket and was able to start the vehicle. After I did that the first time it worked everytime after that and I didnt really do anything else to it. Its been running fine for the past two years.

If I can find the information later today I will try to post up something to see if I can help more. Good luck.

iamaskier87

with key in the run position i checked both wires that feed the coil, both are dead.

pulled both noted fuses in the box and they look good, reinserted them and tested both poles on each and both give power.

swapped asd relay with fuel pump relay, turn key and i can still hear the fuel pump pressurize, car still turns but wont fire or start.

i'm at a loss again

RAH

If you have power out of the fuse and nothing at the part then its a problem in the wire. If you look at the coil pigtail right at the plug. Mine was broken right there. Open up the wire loom and check for power up the wire a little way.

Cherockee

to cavity C12 of the PCM.

So I've found my FSM.... let me do some research and try to track down where this wire goes exactly. Probably wouldn't hurt to check that coil power supply wire for breaks as mentioned earlier