Rough idle at start/randomly stalls when driving

Subscribe
Oct 3, 2014 | 02:18 PM
  #16  
Quote: will do, thanks



I was just going to bite the bullet and replace sensors, but after testing them with the meter I am hesitant
Right on. One thing at a time. Replace the ignition items you mentioned and if that shows no improvement move on.
Reply 0
Oct 3, 2014 | 04:40 PM
  #17  
well here goes nothing. NAPA was out of plugs so I had to go to advance to pick some up. The only champion copper plugs they had were 0.036, will that make a difference?

Name:  1YP8qoYl.jpg
Views: 99
Size:  40.2 KB


Reply 0
Oct 3, 2014 | 06:36 PM
  #18  
Quote: well here goes nothing. NAPA was out of plugs so I had to go to advance to pick some up. The only champion copper plugs they had were 0.036, will that make a difference?

Nice collection there. Santa came early...

Are the plugs RC12ECC (438)? Hope so.

I don't want to be picayunish, but I like to be. The plugs are to be gapped to .035". Use a cat whisker type gap gauge to check them, not those coin looking POS things.
Reply 0
Oct 3, 2014 | 06:49 PM
  #19  
Make very sure you get the plug wires going to the correct spark plugs. Transfer them from the old cap to the new cap in exact order/length.
Reply 0
Oct 3, 2014 | 06:58 PM
  #20  
Quote:
Nice collection there. Santa came early...

Are the plugs RC12ECC (438)? Hope so.

I don't want to be picayunish, but I like to be. The plugs are to be gapped to .035". Use a cat whisker type gap gauge to check them, not those coin looking POS things.
Are you refering to a "feeler gage" ? If so they are cheap. I think I paid around $6 for a set
Reply 0
Oct 3, 2014 | 07:13 PM
  #21  
Quote: Are you refering to a "feeler gage" ? If so they are cheap. I think I paid around $6 for a set
Not feeler gauges. Cat whiskers are those hook like wire gauges. Sears sells them.

http://www.sears.com/kd-tools-spark-...&blockType=G14

My set are very old and are nearly falling apart. I may have to buy a new set.
Reply 0
Oct 3, 2014 | 07:15 PM
  #22  
Quote: Make very sure you get the plug wires going to the correct spark plugs. Transfer them from the old cap to the new cap in exact order/length.
Yep just finished and yes those are the plugs that I bought. I did the ECU reset after as well.

No real change. Idled for a minute or so then stumbled and died like before.
Reply 0
Oct 3, 2014 | 07:21 PM
  #23  
Quote: Yep just finished and yes those are the plugs that I bought. I did the ECU reset after as well.

No real change. Idled for a minute or so then stumbled and died like before.
It sounds like it's running out gas, right?

Fuel pressure?

I still have it in the back of my mind that the CMP is bad but Didn't know of a good way of testing it.
Reply 0
Oct 3, 2014 | 08:18 PM
  #24  
Quote: It sounds like it's running out gas, right?

Fuel pressure?

I still have it in the back of my mind that the CMP is bad but Didn't know of a good way of testing it.
Yep that's exactly what it sounds like. I haven't checked the pressure yet, will do tomorrow.

I just got back from taking it for a little drive. This time started right up and took off smoothly. Drove it a few miles around town and it seemed to do fine. Came to a stop sign and it started to stumble again. Took off and drove for a bit then it stumbled and died. Took a couple times to start it back up, drove fine, then stumbled again, then it stopped, then it would randomly start stumbling again. SOMETIMES it seems like giving it a little gas will get past the stumble for the time being. I've tried to figure out certain circumstances it stumbles in, but really it is completely random.
Reply 0
Oct 3, 2014 | 10:15 PM
  #25  
Went for a ~20 min drive and it drove perfectly. Idled in line waiting for pizza for a good 10 min and no stumbling. Idle isn't 100% perfect but not bad at all. Went and put gas and the jeep started right back up and drove perfectly again. Then I turned down my street.... Stumbled and died. What gives...
Reply 0
Oct 4, 2014 | 06:36 AM
  #26  
Yeah thats frustrating as hell. Let us know how the fuel pressure looks.

If the fuel pressure checks out OK and you decide to replace the crank position sensor, when you install the new one make sure the wires don't come near the exhaust manifold. I've heard of guys discovering the wires half melted.
Reply 0
Oct 4, 2014 | 09:59 AM
  #27  
Quote: Yeah thats frustrating as hell. Let us know how the fuel pressure looks.

If the fuel pressure checks out OK and you decide to replace the crank position sensor, when you install the new one make sure the wires don't come near the exhaust manifold. I've heard of guys discovering the wires half melted.
Plan of action today will be to check the fuel pressure. If that checks out good then I'm thinking check grounds and wires? Then CPS?
Reply 0
Oct 4, 2014 | 10:17 AM
  #28  
Dealer doesn't have a cps in stock. I've read that NAPA carries a good one. Worth the wait for the dealer or should NAPA be g2g?
Reply 0
Oct 4, 2014 | 11:30 AM
  #29  
When you changed your cap and rotor did you check for play in the distributor shaft?

This is an item in the '99 diagnostics manual for P1391.
Reply 0
Oct 4, 2014 | 12:13 PM
  #30  
Quote: When you changed your cap and rotor did you check for play in the distributor shaft?

This is an item in the '99 diagnostics manual for P1391.
Yep it was solid, no play
Reply 0