Nakedginger

Hey, I have a 1990 2 door jeep cherokee with 184,000 miles on it. Two days ago I drove back from Corvallis and my jeep ran fine. then yesterday when I went to start it up in the morning my engine would turn over but wouldnt start. a week or so ago, my jeep took a little longer to start, but it eventually started. I pulled the wire going from the coil to the distributer and tested for a spark. I found I didnt have any. Ive also checked my CPS sensor as well. I hooked up a ohm meter to it and I got a reading of 230 ohms with a cold motor. Does anyone have any ideas to why my jeep doesnt have a spark? I would really appriciate the help!

Gee oh Dee

Cam position sensor, crank position sensor, or bad coil.

Nakedginger

Do you know how you would test each of those components?

Gee oh Dee

Off the top of my head, not at all.

But if it were me, and I needed to know I would first check my Haynes (or Chilton), and then either search this site or run a general google search for the tests.

The info is out there, just have to do a bit of work.

DFlintstone

Lot of guys talk about checking grounds, especially the engine to frame.

The CPS and it's connector seem to be #1 on the list. Mine went bad on my 90 around 1999 I think.

back from Corvallis? I'm in CC. Ca.

Nakedginger

Alright, Ill look into how to check those components on google. Ill also take a look at the engine ground, but I have a feeling one of the components arent working.

Bustedknuckle

Tough call with that many miles.

I'd start with the coil being the least amount of time, effort & cost.

As for the sensors, I'd test them for ohms and resistance.

cruiser54

The best way to test the CPS is by checking the voltage with the sensor unplugged and cranking the engine over. Should have .5 AC volts. Anywhere down near .35 and it might not start.

Nakedginger

Thanks guys for your imput! My dad and I went through the system and found that the connection points between the ignition system and the senors, like the CPS had corroded just enough to not let enough electricity flow threw. we pulled connections appart and then put them back together and then it started right up. When we looked deeper into the system online we found that if ONE of the many sensors dies or looses contact the ignition will freak out or not start at all. Again thanks for all your imput!

cruiser54

Do this. Unplug every connector related to the fuel injection system one by one. Spray the connectors out with a good electronic cleaner, add dielectric grease and plug 'em back in. I do this to every Renix Jeep I work on as a maintenance preocedure.