Stumbling and Hesitation

[menos]

Been fighting a weird one for a few weeks. It's been getting worse and worse. It's totally intermittent with no standard method to reproduce.

Symptoms

• Elevated (1500-1700) idle.
• Hesitation when applying throttle.
• Rich Smell to exhaust.
• Occasionally will only start with the flooded start procedure
• Stumbles and dies when coming to a stop

Here's the fun part. No codes.
It has a new TPS, CTS, MAP and good pulled O2. All within the last month and all after it started acting up.

I've been unable to check the fuel pressure when it's actually acting up, but when I've been able to it seems to be normal.

Any ideas on what to look at next?

 

[westvirginia24976]

His jeep is a 92!

Sounds like a vacuum leak.

 

[menos]

Yes, sorry my heep is a '92 4.0 AW4 231... Not used to not having a signature. Need to correct that.

 

[jasonl2000xj]

What do yours plugs look like. High idle is generally a good indication of a vac leak. How bout your iac valve. Have you cleaned it. I'd start with cleaning that and the throttle body and work from there. Def read your plugs!!!!! They can tell you alot

 

[menos]

Doing some more diag the other night I realized the fuel system wasn't holding any residual pressure. That along with the pump making a horrible noise I decided to swap it with a known good one I had lying around. After swapping the pump it ran fine. I went ahead and swapped the plugs and wires last night just cause they were due. The plugs looked ok but the electrode look to be a little worn down. The gap was in the .060 range.
It ran great today but then again this problem has been coming and going with days going between it acting up.

 

[KTMarquardt]

Check your O2 sensor wiring for the upstream sensor. Had the same problem with mine