Lope/Misfire Only at Idle

[Woody35]

The truck will shake kinda like someone hit your bumper slightly in a parking lot and a puff/haze of black smoke will come out of the tailpipe a second later. No ses light has come on and the truck drives like normal. It happens in park and in gear and the tach doesnt move. It doesnt happen often and when it does happen its random times when idling not consistent. Any ideas on the problem? Thanks for the help.

 

[ak diesel driver]

sounds like a sticky inj

 

[littleboy]

Or the solenoid on the back of the pump....

 

[Woody35]

well i got some power service diesel kleen to loosen up the injector if it is a sticky injector. Is there anyway to test the soleniod on the pump?

 

[Woody35]

well a full bottle of ps diesel kleen and 1200 miles and it has still happened a couple times but not as frequent.

 

[THEFERMANATOR]

When mine started doing this it was the ECM had failed. It is a semi common issue on the 6.5 known as fishbite. Check teh grounds over VERY carefully and make sure they are clean and tight.

 

[sathackr]

My fishbites were from the IP sucking air. Lots of places it can get in, mine was a loose hose clamp on the feed side of the injector pump.

 

[NVW]

Sounds like your LP may be weak if the IP can suck air. The loose hose should have leaked fuel.

My fishbites were from the IP sucking air. Lots of places it can get in, mine was a loose hose clamp on the feed side of the injector pump.

 

[sathackr]

Sounds like your LP may be weak if the IP can suck air. The loose hose should have leaked fuel.

It was leaking fuel...had a pool around it that's how I spotted it. LP was making 6psi at WOT but the needle bounced quite a bit at idle. I think the gauge was leaking too. Fishbites went away once I removed the tee for the gauge and tightened the clamp.