89 Cherokee won't start

I hope someone can help me here, I'm at my wits end. Sorry about the length of the post but here goes.
Awhile back, my wife was driving on the interstate when the jeep died. When I checked it, I found the wires going to the crankshaft position sensor had got against the manifold and melted. I change it on the side of the road and it cranked fine. As she drove home, it started running worse and worse. We got it home and shut it off, and it hasn't started since. The only thing that it will do is run for about 2 seconds when you start it with the throttle in the full position and then it will die. Ok, here's what I have done: Changed CPS again, changed fuel filter, checked MAP, Throttle position sensor and camshaft position sensor, according to Chilton's manual-all ok. Changed manifold temp sensor and water temp sensor, check engine timing (ok), checked fuel pressure (ok),
rebuilt motor because it had 225,000 miles on it and the compression was low, no change still start and die. Changed ECU, no change. Checked coil, again according to manual (ok). Have had it to 2 shops and one couldn't fix it and the other said he didn't have time. After keeping for 3 weeks! Can anyone come up with anything else to try? Has anyone had this problem? My undying gratitude to anyone who can help me on this thing! :banghead:

Did you try changing the engine controller. My 89 Wrangler did the same thing and it was just the engine controller went bad. I have heard that since the ride is so rough in Jeeps that the electronics in the ECM don't last as long as most ECMs.

Hope this helps
Dan

Thanks for the reply are u talking about the computer or the electronic ignition module? I changed the computer but not the module. It is firing though.

hows the vacuum hose to the map sensor? that damn thing can get unplugged when you're messing around near the cps plug. when it comes unplugged it still stays in almost the same position, and unless you atually put your hand on it, it's hard to tell.

I know it's a longshot but I had simular symptoms when my son knocked that hose loose while pulling the temp sender from that area.

Thanks for the reply, but I have checked that along with checking the sensor. :smokin:

:rofl: I found the problem! Thanx all for the advice, but believe it or not, the whole problem was a restricted exhaust. I took the pipe off the manifold and it cranked right up. the really wierd thing is that the pipe has some how gotten stopped up while it was being driven. Go figure. Thanx again!

My 89 Cherokee 4.0 did not start today. I have replaced the plugs. The distributor cap and wires look good. There have been sugggestions in several threads to check the camshaft position sensor and the throttle position sensor - where do I find these???

Is there any other items that I should check?

the cps is on the top/drivers side where your motor and tranny come together.

the TPS is on the front/drivers side of the throttle body

Sorry to have to correct you, but the crankshaft position sensor is the one located where the engine and tranny go together. This is the most likely suspect if you are not getting any fire. The camshaft position sensor is located inside of the distributor cap. Other suspects could be the coil or the ignition module. Check it our and let us know.

your right I thought he was talking about the crank ps, from the discription of the problem.

btw- I've fixed the no-start problem on mine twice, by simply unpluging and repluging the CPS harness connection. even though it has the rubber seal on the conection there is something about that conection that just won't stay clean.

Thanks for the help. You are right, I meant to type crankshaft position sensor. Before trying to contort to reach the cps, I tried the other suggestion I found on the site. I shifted into neutral and the jeep started right up. Lucky me!!

now go ahead and change that neutral safety switch. if you just keep using neutral to start it, i'd guess that eventually the switch will fail completely and leave you stranded somewhere

I was driving home from work one night and i had a similar problem. My drive is roughly 25mins, about four blocks from my house I could smell my back seat burning. I stopped, got out and found my cat was bright red and then the motor died. The cat ended up being clogged. Sux when it works like that, huh?

-KojakLuvsDa'88Jeep :rolleyes: