Hello...new here and of course, I have an issue I need assistance with.


My 1997 Country 4.0 will not start. It cranks, but does not start. I have troubleshot alot recently and am banging my head against the wall right now.

I have changed the coil, battery, and the CAM position sensor. I also changed the CRANK sensor but to no avail. I have read out all three of those connectors for 5v reference and I am getting that.

I have checked for continuity through several harness wires associated with the ignition system and all seems well.

My gauges work. I have 12V at the coil but no spark, even with the new coil in.

I have reset the PCM and TCM and now have no stored codes. Before I did the reset I had...

P0320
P0122
P1694

I did find just today that my aftermarket exhaust was not using what I believe is the 2nd of two O2 sensors. It was just kind of hanging there. I noticed that it had fallen from wherever it was stuffed...(it was like that when I purchased it 4 years ago)...and was riding on the driveshaft. 2 of the 4 wires were completely chaffed through.

Could this be the culprit?

Any help or knowledge is appreciated.

Thanks in advance.

 

Where did you get the new sensors from? Our 4.0's don't like aftermarket sensors. If they are not OEM I would suggest returning them and replace them with OEM ones. Many aftermarket sensors are known to be bad right out of the box. If they do work they have a very short lifespan. Also I know for a fact that the CPS can read good but still be bad. I have had this happen to me and so have many others.

 

I have a buddy at Advance that got me all my parts. I still have the issue of no spark. I really think it may be attributed to this O2 sensor deal.I want to repair these wires. Any idea what colors are for what?

 

Personally I have never seen an O2 sensor cause a no spark. I still have a feeling that it is either your cam or crank sensor which will cause a no spark.

 

Which of the 2 wires were chaffed, the white ones or the grey and black ones?
the White ones are for the heater circuit in the O2s they carry 12vdc. The grey and black wire are the signal and signal ground going back to the PCM. The P1694 code is no CCd bus messages are received from PCM for 20 seconds or invalid messages are received for 20 seconds. If the wrong white wire and the grey wire came together it could toast your PCM. Since your gauges work thats probably not the case.
I know that a CPS can test good but be bad, and aftermarket ones are unreliable.
What about the Distributer check your rotor and cap?
One last idea, have you checked to make sure the rotor in your distributor is turning(possible broken timing chain)

 

As bad as it sounds, it might be the CPS still. Everyone I know that used aftermarket CPS had problems with them, or they never worked and went through a few of them. I have a CPS that will start one of my jeeps, but won't start the other.

 

Doubt the rear O2 sensor is the problem, mine (97) is completely missing. Someone clipped the wires and never reinstalled it.
I think it's either a crank or cam position sensor issue.

 

I will have to go back and look at which wires were chaffed/cut. It got nasty outside and I didn't troubleshoot further.

I did check the rotor inside distributor and it is turning. I replaced that cam position sensor that is in the ditributor cap and looked at that when I was in there.

I understand about the crank position sensors being bad out of the box but damn that thing was 80 bucks. I pulled it back off and put the original back in since it didn't solve my problem.

All my troubleshooting has led me to believe it is the PCM. The suggestion that somebody made about those wires causing a taosted PCM makes sense. I was never suggesting that the O2 itself was causing my problem, but more that those wires may have shorted or what not. I mean they were completely chaffed through to the conductor and touching the driveshaft. The jeep has never had that downstream installed, and has run fine up to this point.

Question about that. If I take each one of those wires and just deadend them with a scotchlock or something similar then that should solve the shorting out issue, correct? Then maybe I go back to the crank sensor again. If that still doesnt fix it, I'm gonna have to believe that the PCM was burnt up by something, probably the O2 sensor wiring.

Another thing about that downstream is, it does tie in with the ASD relay. Wouldn't those wires shorting possibly cause a problem in that circuit?

Thanks again. I look forward to more responses!

 

Did the P1694 error come back? If not and since your gauges work (they are controlled from the PCM) your PCM is probably ok. Save that for a last resort. The ASD relay only has the fuel pump and the O2S's heater on it if I remember correctly.
As far as the shorting, yes it would take care of it but I wouldn't rely on it for long, Temp fix at best.

 

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There are fuses in the PDC you may want check to see if they are blown.

Powered from the ASD Relay - F20 20A - powers the PCM, Ignition Coil, and Fuel Injectors.

Powered from the ASD Relay - F23 15A - Powers the upstream and downstream O2S heaters.

F18 25A - Powers the ASD Relay from the battery buss.

Edit: The Fuel Pump Relay is not powered from the ASD Relay. The FP Relay is powered through F21 15A in the PDC.

 

Thanks. I know that F24 15A is blown and it is a 25A in my Jeep. Many of these are like that. They are supposed to be fuses at one amperage but the PO put some that were higher...like a 25A where a 15A is suupposed to be. I am going to go through and fix that, but it has run fine up to this point like that. Any idea what F24 15A does?

Also, I cut my harness for the downstream and deadended each wire in some silicone filled splice/locks we have where I work. The battery is DEAD from all the cranking but not starting so it is getting re-charged today. Hopefully a difference will be seen after it is charged but I doubt it.

I'm leaning crank sensor (again) or PCM....

Thoughts?

 

This is what we have been telling you all along. Aftermarket cps's are garbage...

 

Just got a price from the local dealership. $106. That is a lot of dough to drop for something that might not change anything.