Attempted to clean CPS. Now Comanche won't start

[driggity]

I'm new to Jeeps so this is probably a useless question but you guys seem tolerant of the noobs so here goes. :cheers:

 

As a bit of background I bought an 88 Comanche a few weeks ago and it has always been a bit reluctant to start but then ran pretty well after it fired up. Since I've had it I've removed, cleaned, and reinstalled the valve cover gasket, replaced all the CCV vacuum lines, changed the plugs, and changed the oil/filter. None of these did anything noticeable to how it ran.

 

Anyways I read something (can't remember who posted it) about using brake cleaner to clean around the CPS in the What is "the most important tip you'd share with MJ owners?" thread so I tried this over the weekend. The only other things I tried to was spraying PB blaster on some suspension components in preparation of replacing them and on the battery hold downs and battery terminals so I can actually get the cables off and replace them so I don't think that will have effected anything. When I tried to start the truck up after doing all of this it completely failed to start. Now it just makes an evenly timed repetitive clicking sound. It sounds louder than just a solenoid. I haven't had time to have my wife try to start the car while I try and pinpoint the noise. I also haven't picked up a spark plug test light yet so I can't confirm that I'm not getting spark. I assume I did something to the CPS so I tried to disconnect the sensor and the truck acts the same way. Does this sound like a CPS problem? I figure it couldn't hurt to replace the CPS so I'll do that but I was wondering if anyone had any other suggestions for things to try so I can just pick them up at the parts store while I'm there.

 

Thanks.

[Geonovast]

What do you mean by clicking sound? Does the motor at least turn over?

 

The CPS is what tells the ECU when the pistons are in the right spot to turn on fuel and spark. With an unplugged CPS, the vehicle will not start or run. Is it possible you installed it backwards?

 

You can test the CPS with it still attached to the bellhousing. Get a multimeter that can test OHMs. It should read between 125 and 275 OHMs.

[Unglar]

I would think that PBBlaster on the battery terminals could interfere with the connection. It would work as an insulator. Go ahead and change the cables and clean the posts this should fix your problem with not turning over.

[jpdocdave]

from your description it sounds like the jeep is not cranking, the motor is not turning, just a clicking noise. a no crank condition is not symptomatic of a crank sensor, the engine will crank away and just not fire if the cps is bad. sounds like a connection on the battery, or bad starter. start with the cables since it seems like you know there's a problem there.

[driggity]

Thanks guys. I didn't know what would happen with a bad CPS so that was just my first thought. Like I said I'm new to jeeps. I'll start with the battery cables and terminals and go from there as it does seem that it's not even trying to turn over. Hopefully it is something that simple and the starter didn't magically choose this time to die.

[Eagle]

You don't need a test light to see if you're getting spark, but the engine has to be tirning over (cranking) in order to do that. Is the engine turning when you try to start it, or not?