First off, this is my first Jeep so I'm wading in deep water here.

I've read a lot of posts here (and other sites) that sound similar to the issue I have, but mostly the OPs found something that worked, I haven't.

I picked up an 88 XJ for $0, the guy was running it last year with a bad head gasket and this year when he tried to get it going it would quit when it warmed up, he messed with it until he burned the starter then gave it to me.

I replaced the starter, it ran like before (blowing exhaust out the valve cover and quit when it got warm). Changed the head gasket and water pump. Now getiing it started was hit or miss, and still quit when warm.

Ran a meter across the coil and found not much resistance from primary to secondary so replaced the coil, plugs, plug wires, and dis cap. Still no good, removing a plug and holding it against the block gives a weak looking yellow spark, sometimes it will start on 2 or 3 cylinders, mostly not at all.

Yesterday I replaced the Crank Sensor, no change to behavior. I've done tests on Cam Sensor, coolant sensor, manifold air temp sensor, MAP and even Throttle position.. all check out.

I'm down to thinking either Ignition Module or ECU, both are fairly expensive and can't find much in the salvage yards for a 23 year old rig.

So, to make a long story longer, would you agree that ICM is the next thing to try? Are there any other (cheaper) things I should try first before trying a new ICM?

 

it could i had a similar prolbem in my case i had no spark its an $80 computer it might be worth a shot try pullin the ecu and look i found mine on ebay cause it sounds like you changed everthing else

 

You might be able to find someone willing to help if you posted, or listed, a location as well. The CPS is the only starting problem I've ever had, and you said you replaced that.

 

Most of the other threads I've read have ended with something like "Replaced CPS and it fired right up", or "Cleaned up the 2 grounds". I guess I'm just lucky...

Location = Nova Scotiain the Great White North

 

Replace coil?

 

Yep, brand new one. Apparently those are spun from pure gold.

I know the old one was near shorted, do yu think it is possible that it fried the Ignition Module on it's way out?

 

Possibe, yes. Know for sure? Nope.

 

what info are you using to base your test of sensors on

 

http://www.lunghd.com/Tech_Articles/...iagnostics.htm

 

Initially I tested the CPS using the procedure from a Haynes manual, when I started searching the internet i found the page you linked and loved it, I used it to test the rest of the sensors.

 

i have one other place that has fsms i will pm you the link

 

Very nice!! Thank you..

I have a wee bit of reading to do now.

 

shhh dont tell nobody everybody will want one ...LOL... hope it helps

 

http://jeep.zerok.ru/index.php?page=124

 

It is a little unclear whether the below applies to your situation. Can you screw driver start it?


https://www.cherokeeforum.com/f51/no...nostics-78934/