ignition problem

[gville38]

hello i have a 1988 mj that is having a ignition problem it will turn over fine but no fire wondering if this is a common occurance or do i have a problem within the ecu any help or previous threads will help

[gville38]

tried a couple things it will start if we push it off and dump the clutch and stays running ?? any help would be appreciated

[maddzz1]

Does a manual have a CPS?

[Eagle]

Does a manual have a CPS?

Yes, but if the CPS was bad it probably wouldn't start by rolling it and dumping the clutch.

 

Otherwise, the CPS would have been my first guess.

[jimoshel]

Check the ignition switch and starter relay. Apparently it will start when pushed, ign sw is on, but will not start when ion sw is in 'start'. Ign sw and starter relay is only things common to both circuits.

[Randy in Maine]

I don't wish to hijack this thread, but my starter just emits one "click"and does not turn the engine over. I can push start it, pop the clutch, and it runs fine. Just no start through the key.

 

I have correct voltage at the battery, starter is acutally good, cables clean and tight.

 

If there is a starter relay in here someplace, could someone tell me where it is, and just what it looks like? What is the test to test it?

 

I am not sure just what the ceramic looking resister over on the drivers fender is for, but the connections to it (the orange/black and orange wires) are good clean and tight.

 

Thank you!

[ComancheKid45]

Sounds like a bad starter itself :dunno:

[Randy in Maine]

Oh and the starter is a nice new Bosch unit. I figured it was the bad thing so I replaced it first (even though the orignal is likely still good). The truck has about 200K on it and it was the original. I am replacing the battery cables tonight with the new good ones since they are original also.

 

When I put the new starter in, I also put some "De-Ox" on the terminals including where the little green wire attaches to try to keep that getting good voltage also.

[jimoshel]

Unfortunately just because something is new is no guarantee it's good. Don't know how much stuff I've took out the box that didn't work. If the starter is mounted run a hot lead direct to the starter terminal from the bat pos. If the starter now works, then the problem is the relay or connection. If the starter is off, hook a cable from the bat neg to the starter frame. Hook another wire from the bat pos to the starter terminal. It should run. It will jerk so have a good hold on it or have it clamped down.

That ceramic thing is a resistor in the fuel pump circuit. Has nothing to do with the starter problem.

[Randy in Maine]

Very good. I am hoping the new cables will solve my problem. Why do they seem to rot out under the sheath so you cannot see there is a problem? (Rhetorical question..no answer needed)

 

Do these things even have a starter relay and if they do where is it located? :dunno:

[jimoshel]

It's sitting right in front of the battery. There is a 8 gauge wire coming off the battery pos about 10 inches long going direct to it. Very top terminal.

[Randy in Maine]

It's sitting right in front of the battery. There is a 8 gauge wire coming off the battery pos about 10 inches long going direct to it. Very top terminal.

 

Very good. I will be poking around in there this weekend. Thank you.

 

This little truck is actually a pretty good little daily driver. I have had it for about 10 years now, put about 100K on it, and really have done little to the engine side of things. It still gets 21 mpg and drives well down the road.

 

I will post my "fix" when that happens.

[JeffN]

referring to the first post check that you are getting power out of the ignition switch when in crank mode

[Geonovast]

The CPS has to see a certain speed before the ECU will turn on spark. The starter may just not be spinning it fast enough.

[Randy in Maine]

I will post my "fix" when that happens.

 

Not sure what the problem, was but I replaced the battery cables (the pos was pretty corroded on the inside) and cleaned the connections at the starter relay. She fired right up. Thanks!