First off I want to say I did search here and all over for hours.

Ok here we go 90 renix has no spark. I installed 703 neon injectors today fired it up and ran fine. Seemed like it had a slight miss at idle<<< (did this before injector swap also) started pulling plug wires checking for which cylinder seemed weak. When I pulled # 4 it was like I pulled three wires at a time. Put wire back on and it cleared up. Walked away as it was still idling and all the sudden idle dropped and started to run rough as hell and died. Started it back up and ran fine, drove it around the block all was well. Got back home opened hood as it was still idling and it did it again idle drops runs will rough then dies, When it did this I heard a relay clicking. Now it will not start and I have no spark.

I have fuel. Pump comes on when I turn key on. The cps has 248 ohms. I have checked all my work and connections unplugged cps multiple times to no avail. I have 12.5 volts through coil. The cps is pretty new also.

One other thing is it has been acting up every once and a while where it wont start, then you wait a couple minutes then she will fire and run fine. It did this again sunday morning Started fine at my house, drove to gas station and wouldnt start back up. Wait a couple minutes then she fires and runs fine. I know this sounds like cps but it tests out fine. But now it wont fire at all WTH.

Is there a way to check coil, icm, etc to rule these out. Or where else should I look.
TY

 

hello i don't know what is wrong with ur jeep but i got a 90 with renix also and was wondering if the 709 neon injectors helped u get better fuel mileage.

 

Check the +12 latch relay, it's one of the four. Check the CPS connector. Have a look under the dist cap, how are the electrodes? corroded? rotor? Check for spark at the coil, put a spark plug on the coil wire and ground it.

 

I have checked the cps connector, I have no spark at the coil but I have 12 volts through the coil.

 

Dont know, didnt make it to far before it quit.

 

that doesn't count, you need also the square wave signal from the CPS that triggers the coil and the only way you can check that is with an oscilloscope. The signal goes through the ECU and the ECU triggers the coil. Now the problem coud be by the CPS, by the electric feed of the ECU and by the ECU itself, without mentioning the worst case that is a broken wire somewhere.

 

I have a '90 and mine did the same thing. Wouldnt get any spark. It was the CPS you seem to have checked that though and it sounds fine. I know you checked the ignition coil but did you check the ignition control module? That tends to go out on Renix Jeeps as well. How old are your Spark Plug Wires? Also try looking at what would normally be a Camshaft positioning sensor but its called a pick up coil on Renix jeeps, inside the distributor. It wont let the ignition coil spark if thats bad. It would be easier to replace the whole bottom part of the distributor than to hasle with trying to get the coil out.

 

Well I have checked everything. The ICM, stator, and coil are all good.
So the only thing left are ECM, and CPS, and or wiring.

 

maybe the problem is there's no MUD in it???

 

Does anyone else out there have any other tests I can perform. I have stated what I have tested. Any help please I am lost now.

 

I had a no start issue with my 89 renix and it was the ceramic ballist resistor next to the airbox. Good luck

 

Ok I have power through the cps, icm, all the fusible links have power through them. There is power at the tps. I have fuel, fuel pump comes on.
I am fricken frustrated.
Where else should I look.

 

Mine end up being a broken ground wire at the knox sensor. Check around the area you were working making sure you did not knox a ground loose or broke a ground.

 

Please help.


https://www.cherokeeforum.com/f2/90-...o-spark-45197/

 

Anyone?