98 XJ 4.0 with the infamous no-start

[Hippie66]

Just a thought... how does the engine sound while cranking it over?

[Dzimm]

Just a thought... how does the engine sound while cranking it over?

Sounds perfect. No weird sounds or hesitation or anything.

[Hippie66]

Spin fast?

[Dzimm]

Spin fast?

Yeah spins at normal starting speed. It usually starts up immediately as the starter engages. It's been the strongest running XJ I've ever seen and I've always been very on top of maintenance and keeping it in tip top shape so this is just weird for it to do this.

[Hippie66]

Since you're not getting power to the white wire, have you checked the 40 amp fuse for the ignition?

[Dzimm]

Since you're not getting power to the white wire, have you checked the 40 amp fuse for the ignition?

Yeah. Checked the fuses as well as swapped the relays around. I even tried running a wire from the battery + to the white wire to for sure provide 12v but it still didn't start.

[Hippie66]

Did you check for fire at the coil wire when you had that hooked up?

[Dzimm]

Did you check for fire at the coil wire when you had that hooked up?

 

I did not check for spark with that hooked up but I did use a test light and it lit up. So I may be getting spark then when providing that 12v. Could this mean that the cam sensor indeed may be bad and causing the engine to just not run?

[Hippie66]

If you cranked it too much with no power to the coil, plugs may have become fuel fouled. That can sometimes kill a set of plugs.

[Dzimm]

If you cranked it too much with no power to the coil, plugs may have become fuel fouled. That can sometimes kill a set of plugs.

Well I hope that's not gonna be the case but on this new set of plugs I've only cranked 4 times and only for a few seconds. I can't imagine that's enough to kill them.

[Hippie66]

That shouldn't hurt them. Had me stumped

[Dzimm]

That shouldn't hurt them. Had me stumped

You and everyone else I've talked to. Even mechanics are having trouble coming up with other options. I've gone through and double checked absolutely everything. The only lead I have is the scanner from today saying it's the cam sensor. I'm keeping my fingers crossed replacing that fixes it.

[HOrnbrod]

That'll fix it.    . :MJ 1: . 

[Dzimm]

Well unfortunately the one I got was about 1/8" too small. I'm gonna have to order one online. Even Chrysler didn't have it anywhere close. Napa had this one in their warehouse but I'm guessing it's for a 2.5l.

[Tex06]

Read through the whole thread and noone mentioned this but on my '92 I just had the MAP sensor fail. Caused a no start condition and I didn't have a CEL. Mine did run when I unplugged the MAP though (not great, and very rich). Possibly worth a try?

 

http://troubleshootmyvehicle.com/jeep/4.0L/map-sensor-diagnostic-tests-1

 

 

Sent from my SM-G930T using Tapatalk

[Dzimm]

Read through the whole thread and noone mentioned this but on my '92 I just had the MAP sensor fail. Caused a no start condition and I didn't have a CEL. Mine did run when I unplugged the MAP though (not great, and very rich). Possibly worth a try?

 

http://troubleshootmyvehicle.com/jeep/4.0L/map-sensor-diagnostic-tests-1

 

 

Sent from my SM-G930T using Tapatalk

I will give it a try. Thanks.

Edit: Just to verify, you're saying yours started when you unplugged the MAP sensor?

[Tex06]

 

Read through the whole thread and noone mentioned this but on my '92 I just had the MAP sensor fail. Caused a no start condition and I didn't have a CEL. Mine did run when I unplugged the MAP though (not great, and very rich). Possibly worth a try?

 

http://troubleshootmyvehicle.com/jeep/4.0L/map-sensor-diagnostic-tests-1

 

 

Sent from my SM-G930T using Tapatalk

I will give it a try. Thanks.

Edit: Just to verify, you're saying yours started when you unplugged the MAP sensor?

Yeah, although my setup is different being an OBD1. Started but ran real rough. If you have a multimeter and a paper clip you can check it properly.

 

Sent from my SM-G930T using Tapatalk

[HOrnbrod]

Well unfortunately the one I got was about 1/8" too small. I'm gonna have to order one online. Even Chrysler didn't have it anywhere close. Napa had this one in their warehouse but I'm guessing it's for a 2.5l.

 

P/n 56041030 is the distributor cam sensor listed for a 98 model. The 97 model p/n listed is 56027023. I don't know the difference. They call it a SWITCHPLATE, Distributor. #7 below:

 

[Dzimm]

 

 

Well unfortunately the one I got was about 1/8" too small. I'm gonna have to order one online. Even Chrysler didn't have it anywhere close. Napa had this one in their warehouse but I'm guessing it's for a 2.5l.

P/n 56041030 is the distributor cam sensor listed for a 98 model. The 97 model p/n listed is 56027023. I don't know the difference. They call it a SWITCHPLATE, Distributor.

I'll have to look and see what p/n the ones I have are.

 

In other news it started!! Idk what exactly fixed it but I turned the key on, put a test light to the pins on the cam sensor plug, on one of the pins it lit up and I heard a click that sounded like a relay around the drivers side firewall area, then unplugged the MAP sensor and tried starting. The starter clicked and everything shut off, no lights nothing, plugged the MAP sensor back in and it fired right up. I let it idle for a few minutes and then shut it off and restarted it. It stumbled a little but I think it was due to sitting for almost a week without running. After another minute or two it started to misfire on one of the cylinders and just lightly feathering the gas made that go away. I will go let it idle for a while over lunch and get up to temp. Fingers crossed I'll be able to drive it home tonight!!!

[Dzimm]

Well I made it home no problem. It's been started and ran several times with no issue. Seems to be fixed to me! Thanks everyone for the input!

[HOrnbrod]

I'm glad it ran for you, but it's not "fixed" unless you know what the problem was (is). Hopefully it doesn't come back to bite you in the azz.

[Dzimm]

I'm glad it ran for you, but it's not "fixed" unless you know what the problem was (is). Hopefully it doesn't come back to bite you in the azz.

This is true. I'm just trying to be confident in it again. I will be carrying spare sensors with me and be prepared for it to reoccur at least for a while.

[shelbyluvv]

Refer to my previous post about the PDC relay clicking while checking the CPS.

[Dzimm]

Refer to my previous post about the PDC relay clicking while checking the CPS.

Oh when you are saying CPS are you referring to the camshaft or crankshaft sensor? I was thinking crankshaft but now it would make sense if you were referring to the camshaft sensor.

[shelbyluvv]

I was saying crankshaft but the relay clicking is the auto shut down. If and when it does it again do as I said. Even though you put a new Crankshaft sensor in it can be bad or a loose connection.