• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Please Help Me Update

roboter

NAXJA Forum User
Here's the update. Still won't start. Have spark and fuel. I've changed the distributor, battery, TPS, plugs, cap, rotor and wires. I've tested the CPS and MAP. Both check good. ECU throws no codes.

I give up...:repair: :dunno:
 
ECU throws no codes, is it running? You should get something unless the ECU is not running.

Of course you would not have spark and Fuel either so forget that.
 
langer1 said:
ECU throws no codes, is it running? You should get something unless the ECU is not running. Of course you would not have spark and Fuel either so forget that.

ECU throws no codes when ignition is on. The motor don't run. Engine just cranks over. I have spark and fuel. If the ECU is bad a check engine light should come on right?

I tried resetting the ECU by disconnecting the battery for an hour. Still won't start.
 
serialphreak said:
x2 put number one at TDC compression and check your rotor position. chain might have jumped.

Yup. Timing is good, rotor rotates. If you read my original thread, all I did was wash the motor, changed the oil, trans and xcase fluids. After I washed the motor, I started it and ran for about 10 mins. Shut it off, did my fluids and Jeep did not start ever since. Put in a new TPS, new dist, coil, rotor, wires, plugs etc etc.
 
You say you have "spark", so I assume you checked at each plug to insure the presence of hot stuff. With regard to fuel, did your check include using a noid light at each injector to insure the computer is talking to them?
 
xjbubba said:
You say you have "spark", so I assume you checked at each plug to insure the presence of hot stuff. With regard to fuel, did your check include using a noid light at each injector to insure the computer is talking to them?

Don't have a noid light but I checked the fuel rail for psi and pulled each plug and checked each cylinder for fuel. There's gas in there but it still won't start.
 
Roboter,

I have read and readed both posts several times and here is what I see:

"Checked the coil with an adjustable spark tester. Spark jumped a gap setting of 24 thousands. Is this an acceptable way to test the coil?"

The spark gap on a new spark plug is 35 thousandths, 24 is not enough! If it won't jump at least 35, or even better 50 thousandths then that is a symptom of the problem.

"Yup. Timing is good, rotor rotates."

How do you know the timing is good. Please be specific, did you set the engine to TDC on the intake stroke and install the distributor with the rotor pointing at the #1 plug wire to be sure?

X2 on the noid light check for the injectors!

Roboter, I suggest you save what money you have left and download some testing guides (and or buy one like a Haynes manual). For instance the Haynes manual and probably several of the free online guides here and elsewhere show how to use a <$10 ohm meter to test the wiring and ECM for obvious shorts and open circuits. It can also be used to test injector solenoid coils, sensors like the TPS, distributor, CPS, battery voltage, grounds (the battery negative to the engine, to the firwall, to the ECU, TCU, etc.

Also just for the hell of it, check around the exhaust manifold for any sensor wires that may have had an unfortunate encounter and shorted an ECU sensor to ground. I lost a brand new O2 sensor just moving wires around one day.

Also, brand new parts can be bad! Get and ohm meter, some directions (sensor testing and ohm meter use directions ) and test them all, new and old!

Seach words to try: sensor testing ohm meter

Also, after every starting attempt, try opening up the throttle to WOT on the next starting attempt to dry out the excess fuel (flooded) that builds every time you crank it with out it starting.

It only takes about 30 seconds of cranking to flood it each time!!!!!!!!!
 
Last edited:
Check your main ignition circuit fuses/fusible links. Also, check all harness plugs in the ignition circuit. If you got one wet inside it could have either shorted something or you could have a corroded connection inside a plug. Another slim possibility is the ignition switch.

I haven't had a need to look yet, but if there is a condenser replace it. After that I'd give up and get it to a place that can diagnose it electronically.
 
Here is a better link on your 91 ignition system.

http://www.autozone.com/servlet/UiB..._us/0900823d/80/15/24/4f/0900823d8015244f.jsp

Also I see that what is called an ECU in my 87 Renix, is called a PCM (Power Train Control Module) in the 1991 and newer Jeeps (sequential Multi-Point Fuel Injection (MPI) System). Also in the 1996 model the PCM is not in the interior cabin but under the hood near the coolant reserve tank (it does not show the 1991 PCM location (?), but if it too is under the hood, where it could have gotten wet, it too is now suspect!

Wish I knew about the 1991 vesion. The Haynes manual I have (1984 -2000, Jeep Cherokee) is not detailed enough about the 91 version. I also discovered that the ICM under my igntion coil (87 renix) is inside the distributor on the 91's.
 
serialphreak said:
x2 put number one at TDC compression and check your rotor position. chain might have jumped.

If the chain jumped.........I have a Question for the REAL:D experts?

Since the ECUs and PCMs gather data from the CPS which detects the crankshaft position and they gather data from the Camshaft position sensor (the distributor stator, Right?) wouldn't the ECU or PCM detect a missmatch of Crankshaft and Camshaft rotation timing caused by the chain jump????????

If the answer is yes, would he get a spark at all??????
 
Guys your not gonna believe this... My Fooking starter just died! I guess turning the engine over so many times trying to fix the no start, caused my starter to no start. It sounds like a wailing banshee when I turn the key.

GOD WHY IS THIS HAPPENING TO ME!!!! :doh:


:hang: :rattle:

I'm really starting to hate this Jeep.
 
roboter said:
Guys your not gonna believe this... My Fooking starter just died! I guess turning the engine over so many times trying to fix the no start, caused my starter to no start. It sounds like a wailing banshee when I turn the key.

GOD WHY IS THIS HAPPENING TO ME!!!! :doh:


:hang: :rattle:

I'm really starting to hate this Jeep.

Look at the bright side, you almost have a new Jeep, why stop now?

Or someday when it is cold, snowing or raining and too dark too see, you will already know where everthing is and how to fix it with your eyes closed! You might even the spare part in the back:D!

Small concellation right now, but hang in there. Hell, the old dead starter could have been going out and cranking too slow! Seems I read somewhere about a minimum cranking RPM to get these guys to start (I think)?

I was :rattle: mine for 2 months before I figured out that I had attached the TPS and O2 sensors backwards (3 wire connectors had A going C, C going A).
 
Thanks for the encouraging words Mike. Murphy's law is hitting me over the head with a 2x4. Funny, how you gotta fix something to get something fixed, and still being unsure of how to fix it. :looney::confused1:looney:

Anyway at the rate I'm going I might as rebuild the motor.
:yelclap:

The manager at my local FLAPS has this shitt eating grin everytime I walk in. :doh:
 
Back
Top