Surging idle after long highway trips?
 

A few weeks ago i had a surging idle issue very intermittently, and it went away for a while so i stopped thinking about it. Just got back from a weekend in vermont, about 130 miles each way, and i noticed as soon as i got to vermont and came to a stop sign it was surging, and when i just got home it was surging again. Why would this have picked back up after long stretches of running for a while? Runs great as far as i know, just have this surging idle for some reason. Any ideas?

What are the ICP and IPR values when it acts up?

Josh

Im so tired i didnt even think to look. I think last time it happened my IPR went down to around 19% and ICP was around 650-700

Did it again today after driving an hour and a half on the highway

http://i284.photobucket.com/albums/l...ps37a5a01d.jpg

So the numbers are holding steady when the engine is running rough?

I'm not sure about the early engines, but 18% is low for IPR, normal is like 21-22% at idle.

I guess that means the HPOP is creating too much pressure? Seems backwards but I suppose it's possible

Josh

Yea i thought the IPR seemed low too. I have one waiting to go in...just need to build up the ambition to pull my turbo haha. I bought one because when i brought it to my friend whos a diesel mechanic (90% 6.0s) he thought it was the IPR

disconned epb sensor and see if the surge goes away. if so suspect either turbo or failed vgt silenoid

Would you disconnect it while the engine is running and acting up?

Josh

Turbo seems to spool quick and responsive, so I think that's fine. The Vgt readings seem to be on par from the values I've seen. I do occasionally get blue smoke in the morning, I think it may be the turbo seal. Doesn't smoke anything at all once I leave the driveway

kind of hard to do at 55mph. but if you could get it to surge at idle then yes

The only time it surged was at idle. It surged today going up a hill at like 20mph and 2k but it was also a cold engine. Switched back to my custom tune and it runs a lot better

sorry i missed that part.
have you updated dummy plugs yet?
ive seen worn plugs cause this too but its not very common.

I didn't think 03s had that problem?

nopw. wow maybe I need to head back to page one and reread .
soory dont mind me

ok so heres my last shot at this one...
03 random surge icp sensor and connector.