non-starting XJ covered some of the basics, help please. Kinda long.

JEONLYEP · May 10, 2005

My Jeep isn't starting. It cranks over but has no spark.

Some info. 91 XJ Sport 4.0 auto. 195K miles (73K I've owned it)

I put a CPS in thinking that was the trouble (NOT IT).

I tested the coil by info given by Runnin'On Empty.

Runnin'OnEmpty said:
Daryl, to test the coil, connect an ohmmeter between the positive and negative terminals (the ones connected to the wiring harness). The resistance should be about .95 ohms to 1.2 ohms at room temperature. (mine tested 1.5)
Then connect the ohmmeter between the positive coil terminal and the high voltage tower (where the coil wire attaches). The resistance should be about 11K ohms to 15K ohms. (mine tested 13.35) Good luck.

Chief93XJ suggested some other tests.

Chief93XJ said:
heres what you do. get a test light. Clip the lead on the negative side of battery turn key on check both wires on coil. one wire should have battery positive voltage with key on. Now switch the clip to the positive terminal and probe the other wire (the one that didn't have power) have a buddy crank the motor while you probe the other (non hot) wire. The test light should flash on and off. If you have both power and a pulsating ground (negative) the coil should spark. If you have both but no spark , bad coil. If you don't have a hot wire with the key on check your fuse (I don't have a hot wire, and the fuse lights the test light on both sides, so it is good) it will be labeled engine igition or something similar, it will probably be in the under-hood relay box.if you don't have a pulsating ground you probably need a crankshaft position sensor. Good luck bro, don't zap yourself- Aaron

Any one have a suggestion as to what to do (test) next?

Thanks

Daryl

JEONLYEP · May 10, 2005

Some other info that may be important.

But this was five weeks ago, and it's been running and starting fine since.

Daryl

Runnin'OnEmpty · May 10, 2005

Daryl, I think your "other info" is indeed important. That's a lot of water, my friend. :exclamati :exclamati :exclamati

Try hot-wiring the coil, by running a jumper wire to the coil positive terminal, from the battery positive terminal or starter relay. If it starts, then you've narrowed it down to the ignition switch area, or maybe a wire connector that got wet.

By the way, disconnect the jumper wire when you turn the engine off.

JEONLYEP · May 11, 2005

Okay I figured out which wire is the pulsating ground. (which does flash when cranked) Since I've been working by myself, I waited until it was dark, then looked under the hood to see which side of the plug would light. Tomorrow, I will try jumping the other side of that plug to see what happens.

any one else with some thoughts about this problem, I'm still taking advice.

Runnin'OnEmpty & Chief93XJ, thanks a bunch for all your help, I'll let you know things turn out tomorrow.

Yea, it was a bit deeper than I thought. A floating XJ gets very little traction.

Daryl

Dirt · May 11, 2005

did you check the dist cap it could be corroded as hell. are you getting spark from the coil? if so are you getting spark out of the dist?

JEONLYEP · May 11, 2005

dirt714 said:
did you check the dist cap it could be corroded as hell. are you getting spark from the coil? if so are you getting spark out of the dist?

Opps, Forgot. When the CPS didn't do it, I pulled the cap and rotor. They were a mess. They are new now. Still no go.

Thanks

Daryl

Dirt · May 11, 2005

ok i don't know your experience so no offense. have you taken the coil wire off at the coil and checked for spark there? I don't mean to babystep you but if your connector is lighting your testlight like you state your coil should be firing.

Dirt · May 11, 2005

nice shorts btw. lol

JEONLYEP · May 11, 2005

Thanks (about the shorts) it was a cold day, and even colder water.

One side of the plug going to the coil is a puslating ground, which tests good. The other side of the plug as I understand should be 12 + when the key is on, which doesn't test good.

No spark leaving coil.

No offense taken. I may need baby steps to get me thru this.

Thanks again

Daryl

Dirt · May 11, 2005

man I'm sorry I can't get the wiring diagrams to show. mabey i can get them in the morning.

JEONLYEP · May 13, 2005

Runnin'OnEmpty said:
Try hot-wiring the coil, by running a jumper wire to the coil positive terminal, from the battery positive terminal or starter relay. If it starts, then you've narrowed it down to the ignition switch area, or maybe a wire connector that got wet.

It's still a no go. I'm quite sure that I had everything set up right, but it still just cranks.? But what I don't understand is if I have the pulsating ground and 12+ to the other side id should be sparking? WTF? what else is there?

Thanks again

Daryl

pcsutton · May 14, 2005

Ignition control module, maybe?

JEONLYEP · May 16, 2005

Or check the relays under the hood. A bad relay can keep it from starting. Ask me how I know

:dunno: :shhh:

Daryl

non-starting XJ covered some of the basics, help please. Kinda long.

JEONLYEP

NAXJA Forum User

JEONLYEP

NAXJA Forum User

Runnin'OnEmpty

NAXJA Forum User

JEONLYEP

NAXJA Forum User

Dirt

NAXJA Forum User

JEONLYEP

NAXJA Forum User

Dirt

NAXJA Forum User

Dirt

NAXJA Forum User

JEONLYEP

NAXJA Forum User

Dirt

NAXJA Forum User

JEONLYEP

NAXJA Forum User

pcsutton

NAXJA Forum User

JEONLYEP

NAXJA Forum User

Similar threads