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ICM

Yeah I tried it.Would that cause no spark and the fuel pump from not turning on though?I am going to get my ICM tested if Advance auto parts can do it.I thought i would test that becuase it would explain why im not getting spark and the fuel pump is not turning on.
 
lawsoncl said:
Yes, a bad CPS would cause no spark and no fuel.
Click to expand...

However it would not keep the fuel pump from turning on when the power is turned on!

No CPS signal, means no spark and no fuel injector signals.
 
Ecomike said:
However it would not keep the fuel pump from turning on when the power is turned on!

No CPS signal, means no spark and no fuel injector signals.
Click to expand...

True, the fuel pump should cycle on when the ignition comes on. It will turn the pump off again after a few seconds of not seeing a signal from the CPS though.
 
You haven't mention what year or engine (hint, hint). I'm guessing Renix 4.0l. This might be of some help. I noticed the 88 FSM shows some of the 4.0l engine came with an HEI setup? Does this mean it would be an easy retrofit?
ICM.jpg
 
ok well i replaced the icm,cps,coil and im still not getting any spark and the fuel pump wont turn on.the motor is an 88 2.5 litre.this is trying to be my DD.anyone have any ideas at all??
 
just updating you guys...i had someone help me with this one...When i start crankin' it over it gets spark from the coil to the distributor and then stops until i quit crankin' it over.So between when i start and stop crankin it im not getting spark...Any ideas at all?!!!1 is it maybe a short in the wiring??
 
The other things mentioned in the FSM are to verify that the battery is good and that you have good voltage between the A & B pins on the #1 connector. Minimum acceptable voltage is 9.5 volts while cranking (might explain why spark stops after cranking a bit?). Also verify that the grounds for the ECM and ICM at the dipstick tube are good.
 
alright well A is getting over 13 volts.C is getting .05 if that matters.i checked the grounds on the dipstick and there both good.Im going crazy with this thing.I also noticed that the ICM got really hot like burn my skin off hot.Im pretty sure its not supposed to get hot like that.
 
just curious but on my perticular jeep(88' cherokee limited with a 2.5 litre) are there any wires to the dizzy?is there anything inside the dizzy besides the rotor?I went to a junkyard and found the same motor and setup but it was exactly like mine basically empty.
 
cant remember if the 2.5 has a sync sensor(cam position sensor)inside the dist or not...I know the 4.0 does...
what idiot would swap a 4.0 to a 2.5???
 
andyanderson said:
alright well A is getting over 13 volts.C is getting .05 if that matters.i checked the grounds on the dipstick and there both good.Im going crazy with this thing.I also noticed that the ICM got really hot like burn my skin off hot.Im pretty sure its not supposed to get hot like that.
Click to expand...

Does not sound like you ran the test properly. You need to test that voltage while someone else is cranking the engine over. The starter drops the voltage while cranking, if it drops below 9.5 (I'd say 9.9 to 9.8 V) per lawsconcl below then the spark will drop out.

Also might look into a ballast resistor problem for the no fuel issue, bit I would solve the spark loss problem first.

The 2.5 L probably does not use or need a synch sensor, thus when the PO switched out the 2.5 for the 4.0 I suspect they switched out the ECU as well since the ECU was different. 2 less Fuel Injectors, different dizzy, different CPS, different flywheel notches sensed by the CPS for starters. You need to do some more digging into the 2.5/vs 4.0 differences for 88. Do you have an 88 Fuel injection Renix FSM? If not PM me your email addy.

Good news is, a lot of stuff is the same for both engines.

So far it sounds like like an electrical overload (short) problem somewhere.
 
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