misfire at idle

L

Leaton24

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Jul 15, 2012
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2005 6.0 installed new 175 75% injectors, now after engine is up to operating temp intermitten miss at idle. what are some issues to cause this, no power loss or miss except at idle.
 
Probably 50 miles. Roughly.

And already checked over the electrical if that is what your talking about.
 
Could be air, can take up to 250 miles in some cases to expel all the air from the hpo system
 
Ford says 3k rpms for 3 minutes to bleed the HPOP system of air, or just go out and romp on it. I have a hard time believing that's your issue, but it's possible. Who built the injectors? Were they built from new or from remans?

Did you have your tuning updated for the new injectors?
 
The injectors are rebuilt reman warren injectors and have not updated any tunes for the injectors, talked to gearhead and they said might have to tune it for lower fuel pressure, but after installing the injectors and finding the problem, i installed the blue spring to raise fuel pressure and it helped alot.
 
Do you not have a fuel pressure gauge on there? You really should, even on a stock 6.0. IMO it's the #1 most important gauge on a 6.0. You REALLY should have it on with bigger sticks.

So you found the problem? You say you did, but say the blue spring helped... kind of confusing, did it actually fix the issue, or just kind of help it?
 
The truck is not mine, trying to help a buddy out, so no my choice to put a fuel press. gauge in.

As for the problem the blue spring did not solve the misfire at idle, it made the misfire less sporadic, as i said above it only helped but did not solve the misfire.

As for the warren injectors they are great until it idles down.
 
Has a cylinder contribution test been run? Seems like without the fuel pressure gauge and without running any testing, we're sort of shooting in the dark here.

Did it have this problem before the injectors? It wouldn't be the first time I've heard of issues with his injectors. I think my buddy was under his valve covers 3 or 4 times before having 8 working injectors. With that said, Jesse is a stand up guy and covered all of the parts without question.
 
Yes contribution test had been ran. Order some tunes from gear head and the misfire/stumble went away.
 
Hmm, now that's interesting. If you put it back to stock tuning do you still get it? I notice this between some tunes on stock injectors even, must just be the difference in ICP commands within the tunes. If the tune is asking for more injection pressure it probably smooths out. Let us know how you make out with it. Also what oil are you running? Are you running any oil additives at all either?
 
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