94 Cherokee wont start

Fenderstrat72 · #1 (**permalink**) 09-27-2007, 09:45 PM

A friend of mine has a 94 Cherokee with the inline 6 engine. He parked it for serveral weeks. When he went to restart it the battery was dead. Recharged the battery and tried to start it and it wil turn over but will not start.

Here is what I know so far. The fuel pump does not come on when the switch is turned on. You can manipulate the relay and the pump works fine.

We did a spark check on one of the spark plugs and got no fire. Also did the same with the coil and no fire.

Hooked up engine analyzer, not a code reader but a real analyzer. The PCM would not talk to the analyser, like the PCM was not getting power.

I checked ever fuse I could find, under the hood and inside the vehicle. I even swapped some of the relays around and still nothing.

I do think there is either an alarm system stopping voltage from getting to the PCM or the PCM itself is bad? Any and all help would be appreciated.

Bounty__Hunter · #2 (**permalink**) 09-27-2007, 11:48 PM

Check the ASD relay (auto shutdown). Also try giving it some gas while cranking (I know, shouldn't have to with FI and sounds strange, but it has worked for me on rare occasions).

Fenderstrat72 · #3 (**permalink**) 09-28-2007, 07:37 AM

I have already swapped the ASD relay with one of the other relays. I can't remember what all they go to but there is about four relays with the same part number in that fuse block.

I will try the accelerator pedal trick however as I said before, the fuel pump isn't even coming on when you turn the key. Also the PCM doesn't seem to be getting power.

LauraBoston · #4 (**permalink**) 09-28-2007, 07:53 PM

you check the iod fuse?...well pcm should be getting pwr even if that's blown...you got pwr at the pump? is the fuel pump fuse blown? the pump only comes on for a few seconds when the key is turned.

LauraBoston · #5 (**permalink**) 09-28-2007, 07:57 PM

oh and have you checked to see if there is fuel pressure? 49psi +/-5psi...if you don't have a guage..take a line off and crank it..is there gas in it? stupid questions but it happens...before parking it did he/she do anything to it?

Fenderstrat72 · #6 (**permalink**) 09-29-2007, 12:40 AM

The problem is not with the fuel pump. The pump does not come on when you turn on the switch but I can manipulate the relay and make the fuel pump work. The pump should come on when the switch is first turned on till the correct pressure is reached.

The problem is electrical. I am getting no power to the plugs or coil. The PCM is not getting power or at least it will not talk to the analyser.

I have checked all of the fuses I could find. One fuse block under the hood on the passenger side and one inside the vehicle on the passenger side of dash. If there are any other fuse blocks located on this vehicle?

I need to know where the security system is located on this thing and if the security system would cause this problem?

Any help would be appreciated.

Fenderstrat72 · #7 (**permalink**) 10-03-2007, 08:10 PM

Bump!

98xjonn33s · #8 (**permalink**) 10-04-2007, 02:38 PM

i had a similar problem with my 98 xj and i changed alot of sensors and relays and it ended up being the pcm. thats my best guess at it and good luck.

Fenderstrat72 · #9 (**permalink**) 10-17-2007, 09:00 PM

If I buy a new PCM, does it have to be programmed or can I just install it?

zanerzack · #10 (**permalink**) 07-27-2008, 10:55 AM

old post but I will add info anyway.

When this happened to me, you must put the key in the door, turn to lock and unlock with the key.

Now she will start. Something to do with the security system.
This must be done every time the battery is removed or charged.

Kanifler · #11 (**permalink**) 07-28-2008, 01:24 PM

Quote:

Originally Posted by zanerzack

old post but I will add info anyway.

When this happened to me, you must put the key in the door, turn to lock and unlock with the key.

Now she will start. Something to do with the security system.
This must be done every time the battery is removed or charged.

HOLY CANOLI!!! Now thats an answer