Engine "loping"?

[steved]

Fired the truck this AM (first in about a week)... it was plugged in, only got into the 20s last night...



Drive to the local fuel stop about 5 minutes away, shut it down to go inside. Restart it when I come back out and it sounds like it has a mild cam (the grid heaters were still cycling)... nothing major, just a little bumpiness... it was still very mildly doing it once the heaters quit cycling... and it didn't seem to affect it the rest of the drive...



I ran it for about 4 miles against redline following traffic (a whole whopping 96mph)... and I was actually losing ground some of the time... seemed fine once I got to work and fully warmed up (trip is around 50 miles)...



Any ideas?? Or is this just one of those "things" that happens that may never happen again??



steved

 

[Bodie]

Fired the truck this AM (first in about a week)... it was plugged in, only got into the 20s last night...



Drive to the local fuel stop about 5 minutes away, shut it down to go inside. Restart it when I come back out and it sounds like it has a mild cam (the grid heaters were still cycling)... nothing major, just a little bumpiness... it was still very mildly doing it once the heaters quit cycling... and it didn't seem to affect it the rest of the drive...



I ran it for about 4 miles against redline following traffic (a whole whopping 96mph)... and I was actually losing ground some of the time... seemed fine once I got to work and fully warmed up (trip is around 50 miles)...



Any ideas?? Or is this just one of those "things" that happens that may never happen again??



steved

My dads truck has loped ever since I put a set of injectors in, but I doubt that is your problem. I dont see any in your sig.

 

[steved]

My dads truck has loped ever since I put a set of injectors in, but I doubt that is your problem. I dont see any in your sig.

No, truck is pretty much stock... the only change is the FASS, Rokktech, and airbox...



steved

 

[Bodie]

No, truck is pretty much stock... the only change is the FASS, Rokktech, and airbox...



steved

Hmmmm... . weird

 

[staarma]

My truck does it when it's cold and not plugged in. I also get a little white smoke with it on initial startup. If you rev it to 1000 RPM and hold it there for a few seconds it will clear right up and go away, mine does.



Just to head anyone off. I know there are TSB's for my truck for the white smoke, etc. but I ahven't been back to the dealer since I bought it and don't plan to now.

 

[steved]

Just to head anyone off. I know there are TSB's for my truck for the white smoke, etc. but I ahven't been back to the dealer since I bought it and don't plan to now.

I had this TSB done IIRC, along with the mpg one too...



steved

 

[tp0d]

I get lope on my 05 when its very cold out, even if plugged in. . When it self-rev's to 1000rpms, the lope is still there, just faster. Wonder if the CP3 takes a while to warm up and get the rhythm going... ? the lope goes away when engine temps move off the low point.



How ya like the rokktech sensor steve? I can definetly say I gained 1mpg, pretty good mod that doesnt void warranty. .



-j

 

[steved]

I get lope on my 05 when its very cold out, even if plugged in. . When it self-rev's to 1000rpms, the lope is still there, just faster. Wonder if the CP3 takes a while to warm up and get the rhythm going... ? the lope goes away when engine temps move off the low point.



How ya like the rokktech sensor steve? I can definetly say I gained 1mpg, pretty good mod that doesnt void warranty. .



-j

That might be it... simply was cold blooded... never had it happen before that I could remember...



The rokktech, gave me a slight increase... probably 0. 5 mpg or a little more... cheap easy mod IMO...



steved

 

[KennethS]

Running to rich I would guess

My Model T when I richen up the gas the engine lopes and I turn it down the ngine smooth out. So I would say to rich in fuel

 

[05mxdiesel]

My truck does it when it's cold and not plugged in. I also get a little white smoke with it on initial startup. If you rev it to 1000 RPM and hold it there for a few seconds it will clear right up and go away, mine does.

Mine does this exact thing unless I let it plugged in over night. Its really weird because last winter it did not do it at all and neither the year before. I get a small puff of white smoke as well. Reminds me of days with my old Powerstroke except it did a complete white out for a couple minutes.

 

[steved]

Mine does this exact thing unless I let it plugged in over night. Its really weird because last winter it did not do it at all and neither the year before. I get a small puff of white smoke as well. Reminds me of days with my old Powerstroke except it did a complete white out for a couple minutes.

Hmmm... ULSD maybe... that is about the only thing I could think of... although we have been getting it on and off around here for a while...



steved

 

[Blacksdieselhp]

Sounds like the FCA is bad on the injector pump. It is located on the driver side of the pump. You'll see where the small wiring harness plugs inot the back of the FCA. Easy to change. I've done quite a few on trucks with lopey idle. Some of them would go from 400 rpm to 1000 rpm back and forth. But anyway. Hope this helps.

 

[steved]

Sounds like the FCA is bad on the injector pump. It is located on the driver side of the pump. You'll see where the small wiring harness plugs inot the back of the FCA. Easy to change. I've done quite a few on trucks with lopey idle. Some of them would go from 400 rpm to 1000 rpm back and forth. But anyway. Hope this helps.

Where to get one and about how much?



Any other "symptoms" of a bad FCA?



steved

 

[betterthanstock]

Steve, it may be the FCA, but it may not be.

On my 03, before I had injectors honed, it started to do that loping when cold, and a slight knock on one injector. I wanted to take it in, but knowing what a pain it is to deal with DC, I used injector cleaner, and even ATF. It went away for a while, but then came back. . Right before honing the injectors, it was coming back, and I was worried whether or not I should get injectors replaced or whatever, but since I've honed them, it has been running flawlessly. I wonder if it's just carbon buildup (more on one injector than the others)

Try towing hard, or just cleaner+lubricant. I don't believe the ULSD is sufficiently slippery. If that doesn't work, then removing the injectors for cleaning may be the only way to do it.

If you're still in warranty, take it in and have them document your complaint, so that if an injector needs replacement later, they will cover it.

 

[steved]

Steve, it may be the FCA, but it may not be.

On my 03, before I had injectors honed, it started to do that loping when cold, and a slight knock on one injector. I wanted to take it in, but knowing what a pain it is to deal with DC, I used injector cleaner, and even ATF. It went away for a while, but then came back. . Right before honing the injectors, it was coming back, and I was worried whether or not I should get injectors replaced or whatever, but since I've honed them, it has been running flawlessly. I wonder if it's just carbon buildup (more on one injector than the others)

Try towing hard, or just cleaner+lubricant. I don't believe the ULSD is sufficiently slippery. If that doesn't work, then removing the injectors for cleaning may be the only way to do it.

If you're still in warranty, take it in and have them document your complaint, so that if an injector needs replacement later, they will cover it.

I would think it would have come on slowly and not just did it this one time if it was carbon build up??



I was wondering about the FCA because when I come to a stop, like to a light, and just push the clutch in, it will cycle up and down about 50RPM or so... more noticeable with the AC on (engine load). It will usually do it about 6 times and level out.



I had heard about the FCA before... just hadn't gotten around to it.



I will add that I sure HOPE its not an injector problem!!!



steved

 

[staarma]

The engine RPM fluctuating when pushing the clutch in is normal. The engine is looking for a relationship to RPM and ABS speed.

 

[steved]

The engine RPM fluctuating when pushing the clutch in is normal. The engine is looking for a relationship to RPM and ABS speed.

I see... someone told me this was a classic symptom of a failing FCA at one time... but my truck has done it since day one... and I now have 100k on it...



steved

 

[steved]

Well, I hope it is fuel related or my paranoia, but I sure feel like it is taking longer to crank over now than it did before...



steved