93GC cranks but no start, check engine light!!

[adgoitd]

rksnc, prestonB is refering about the fact of interal failure in the PCM causing the car not to start right away, the MAP sensor doesn't have to be with the ignition system, it's a part that coordinates the fuel/air mixture into the engine, and besides the MAP sensor gives a code and also if the MAP sensor is bad, the car would hesitate or even stall!

[PrestonP]

good point. I discovered that my "check engine" light will come on if I just turn the key to the "ON" position and wait a bit. Some relays click, lights come on, etc. With a few of these attempts, voila, the "check engine" light comes on and VROOM, she starts up perfectly. Hmmm...

PrestonP

[adgoitd]

haha, isn't funny the way the car reacts to you?, well this was my day off and i spent around 1300 dollars with one saturn, during the last 2 weeks, and now i'm glad my jeep is doing it good, in the past my car was a piece of garbage, right now it's my right hand! ... JUST IN CASE preston! , have you seen one cable (very tiny or thin) that goes near the battery, it's a kind of connector, well that is the ground connector of PCM, try to unplug it and plug it back in, you will hear a very small clicking sound when you have your key at ON POSITION, this indicates the computer is shot , quick diagnostic!! without taking the PCM out of car

[adgoitd]

nart86, you don't need to spend around 70 for a good diagnostic, your computer is going bad! the PCM whatever is called, you should be change it as soon as you can otherwise the car won't be able to start one more time, if you need info, send me an email i will be glad to answer all your questions and give you info for the computer

[rksnc]

Quote:Originally Posted by nart86
hi, I'm having trouble with my jeep laredo
It cranks but doens't start
It takes like 4 times to start but today it took like 10 times in the cold.

I noticed that it doesn't start unless the check engine is on. all the other lights come on exept the check engine light. It takes a few times to appear.

I don't think it's the fuel pump cuz i hear it clicking immedtly after turning it on. I also don't have any problems with acceleration or idling.

I'm going to change either the crankshaft postion sensor or camshaft....
but I don't know which .

I recently did a tune up and I have spark.


need help asap

thanx

I just let some mechanic take a lokk at it . He said he needs to dianose it for 75 lol.
I checked the codes and got code number 13. does this have anything to do with my problem. I also told him that it might be from the CPS but he doubted it saying that it has nothing to do with the check engine light. and that it would never start up.

He said it might be the computerbut i don't trust him lol.

as i said my car doesn't start until it sees the check engine light and the mechanic says it always has to be on and that the CPS doens't effect the check engine light.

This is what I replied to.
Not prestonb
If you will see there have been alot of replies.
The computer look at the map when key is turn on as baro reading. After that it is going to look at it as a map sensor. But with the engine doing as it is that could easy make that code happen. I have seen this happen to many times. As I replied I did not think the map has anything to do with the not cranking. I know what it will do to a running engine but guess what . this one doesn't run.

[macman405]

I'm going to jump in here and side with adgoitd. I have a 93 JGC. Really beautiful car. Runs nice but last year we had pure hell, getting stranded everywhere. Seems it was worse in the hot weather. The first time it happened we were out-of-town. A Jeep dealership diagnosed it and replaced the fuel pump. $700. Probably was going to go out anyway, but that wasn't the problem. A couple weeks later it did it again. This time, we had a local dealership look at it. They wanted to replace the fuel pump too. I knew that wasn't the problem because you could let it sit there a few hours and it would start up right off. So after some on-line research and stuff, I decided to do all the pull and replace stuff I could that wasn't too high tech. I first replaced the coil. Then I tried disabling the alarm system. Then I replaced the CPS. I also replaced the Idler valve. Finally, I replaced the fuel pump and ASD relays. Then fall arrived and it seemed to be fine. All winter it's ran fine. Then today, the first day with temps in the 90s its back to its old form. I believe its the PCM shorting out due to high temps. So I'm going to replace it. I'll let everybody know how it works out.

[cookie2]

Not to appear really stupid, but what is a PCM?

[StacyB]

It was the computer!

$130 (plus core) from Schucks for the one I needed. Starts right up every time now. The installation was easy. (4 screws, 5 counting the windshield washer reservoir removal)

Good luck!

[PrestonP]

Good news!
It was the computer in my case too! I got a new one from a parts dealer and life is good. My alarm problems also seem to be fixed. Thanks everyone.
PrestonP

[PrestonP]

Does anybody know something about the need for computers to "relearn"? At times my vehicle runs very smoothly, and at other times it gets choppy, the Jeep even stalled twice today! Any thoughts? Any way to help my computer relearn without the rough ride?
Cheers,
PrestonP

[mkmcphrsn]

Originally Posted by nart86

hi, I'm having trouble with my jeep laredo
It cranks but doens't start
It takes like 4 times to start but today it took like 10 times in the cold.

I noticed that it doesn't start unless the check engine is on. all the other lights come on exept the check engine light. It takes a few times to appear.

I don't think it's the fuel pump cuz i hear it clicking immedtly after turning it on. I also don't have any problems with acceleration or idling.

I'm going to change either the crankshaft postion sensor or camshaft....
but I don't know which .

I recently did a tune up and I have spark.


need help asap

thanx

it sounds like your crank sensor has gone bad

[rksnc]

I would go with the crank sensor.

[Jeeppr]

I'm having trouble with my jeep cherokee laredo 1994
It cranks but doens't start in morning or cold It takes many times to start. that it doesn't start unless the check engine is on. all the other lights come on It takes a few times to appear.

please how do you resolve your equal problem

mi e mail is

abccafe19@hotmail.com

micomputer is # 56027-896

mopar informa the 56028311 is compatible

Is the computer mi problem??????

Please help

[StacyB]

Yes. Go to Schucks and get a new computer. That was it for me anyway. Easy install.

Regards,
Stacy

Originally Posted by Jeeppr

I'm having trouble with my jeep cherokee laredo 1994
It cranks but doens't start in morning or cold It takes many times to start. that it doesn't start unless the check engine is on. all the other lights come on It takes a few times to appear.

please how do you resolve your equal problem

mi e mail is

abccafe19@hotmail.com

micomputer is # 56027-896

mopar informa the 56028311 is compatible

Is the computer mi problem??????

Please help

[bringselpup]

X2 Piece of cake to swap.

Disconnect the battery + before plugging in the big connector!!!!

Troubleshooting:

Listen for the fuel pump when you key on. The Computer tells the fuel pump to run for 1 second to pressurize the fuel rail before you start. As mine went bad it would take longer and longer to do that. (Key on not engaging the starter) First it took maybe 15-20 sec and just before it died for good it was taking 15-20 min.

If you don't hear that pump spin when you key on you are not going to start no matter how long you crank that motor.

You can check if your fuel pump is running by opening the PDC and finding the fuel pump relay. Unplug it and carefully take the cover off the relay and put it back in it's socket. Manually make the relay make contact. Just for a second or two. Have someone in back to listen for the pump. If it's quiet where you're working on the vehicle you may be able to hear the fuel pressurize in the rail yourself if no one is around to listen in back for you.

Changing the PCM did it for me. I used a Cardone Reman from Advance Auto Parts. $210