1990 Jeep Cherokee - Turns over, but won't start - Please help

[janetp1977]

I have a 1990 Jeep Cherokee Limited with 118000 miles. Straight 6 - 4wd. It generally runs great. Has a minor leak in a seal in the engine - no oil drips. Anyway, I drove it yesterday and parked it overnight in the garage. This morning, I went to start it and it would not start.
The engine would turn over and over, but no start. Usually it takes the engine 3-5 times to turn over while I hold the key forward, but this time nothing.
Since the battery is getting old I thought I should charge it and try again (I did have it tested a few weeks ago and it was fine). Well, nothing happened - although, when I tried to crank it the battery gauge would drop down to a low level. So, I tried using the jumper cables to jump it off - same thing - it just kept turning over, but wouldn't start.
A friend of mine felt the fuel lines and said that fuel was running through them fine.
We changed around the relay switches (there are 4 of them) and nothing happened.
Then we looked at the Ignition Coil and Module (?) right next to the relay switches. He said he did not get a spark at the coil - or at the plug going into the distributor cap.
So, I took off the Coil and Module and had the Coil tested at AutoZone - it was fine. They said they could not test the Module.
So, I guess I will put them back on in the morning.
I really don't want to have to tow it into a mechanic if I can help it - Please can someone help me?
I did have one friend suggest that maybe the timing chain slipped, which would mean I need to get a new one? I thought they never messed up?
Thanks to anyone who can help!!!!!

[bmwilson]

Have you tried playing with the crank sensor? It is a consistent problem on cherokees over 100,000. Especially standard models. The topside connection is located near rear driver side of engine. Good luck and please educate me if it is something else.

[janetp1977]

Do you happen to know where I can find a diagram that would show me the crank sensor? Or, could you describe exactly where it is? Thanks!!!
Also, can I take it off and get it tested - or do I just need to replace it?

[Cam7]

There is a ballast resistor on the inner drivers side fender for the fuel pump. Try running a jumper wire across the terminals to see if it will start or try holding the gas pedal all the down this by -passes the resistor. If it works you can by-pass it or replace it. The Crank shaft Position sensor is located in the tansmission bellhousing left rear side of the Engine Block.Dont know the flow chart for testing the sensor. It will also cause a no start condition.

[janetp1977]

OK, I wiggled and replugged everything that looked like a sensor to me and suddenly the Jeep started. Now what do I do to actually find out what the problem was? The Plugs that I messed with were all to the rear of the engine - both on the left and right side. Should I take it to a mechanic? Can an AutoParts store test the parts that need to be tested?

Thank you, Thank you.

[Dale Aeppli]

Originally Posted by janetp1977

OK, I wiggled and replugged everything that looked like a sensor to me and suddenly the Jeep started. Now what do I do to actually find out what the problem was? The Plugs that I messed with were all to the rear of the engine - both on the left and right side. Should I take it to a mechanic? Can an AutoParts store test the parts that need to be tested?

Thank you, Thank you.

HI, IT SOUNDS LIKE YOU HAVE A BAD CRANKSHAFT SENSOR OR THE WIRING ON THE CRANKSHAFT SENSOR IF YOU EMAIL ME I'LL SEND A PICTURE OF THE CRANK SENSOR AND WHERE IT IS LOCATED. DALE
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[Ironic]

I know from experience it ain't no picnic getting to that sensor- You may try testing it first:Crank position sensor test...
With engine off, A+B should equal 200 +/- 75 ohms
with hot engine. also when measuring voltage, volts should spike when engine
is cranked or is running. If no reading, CPS is bad. Oops, disconnect sensor
when doing ohm test...
Since you got it started by playing with connectors- I would think your best bet would be to disconnect those that you played with- spray em up with electric contact cleaner, scrub them down where you can (i use a saturated toothpick (on the female, and a toothbrush and small screwdriver on the make) and pack the connectors with electrical grease.