I thougtht about that, but wouldn't bad gas make it miss? This was a severe surging as if you were pumping the throttle. No sputter at all, very rythmic.

 

I highly suggest taking it back to stock... that tuner might have something to do with your problem.

 

I do not see where the tuner causes his problem.

 

sounds like you may have just had some bad gas. You should see how our cars at work run during and shortly after a stand alone B.G. fuel injector service

 

Nobody is saying positively it is the tuner but the name of the post was "Problem not seen."

I have seen this problem.
It was a combination of a weak battery and tuner.
Stock, the weak battery didn't effect performance.

 

Unless it has gone defective, the battery should be strong, less than 2 years old and gets a steady 14.4 volts.

 

All im saying is that I have seen a tuner in "tune mode" have these same symptoms that were not there in "stock mode"...bucking, surging...bogging down at WOT after downshift. Let off and acceleration was smooth.

 

im pretty sure you have an edge so my suggestion is to monitor FRP while doing a wide open throttle run and watch for a drop. It should not go below 40psi. Sounds to me like you are loosing fuel pressure in higher RPMs.

 

His battery is good.

The tuner can exaggerate an existing fuel or engine problem, which is not a problem at all with the custom tune. Stock tuning could cover up that problem with the conservative stock tuning.

I'm thinking he got some bad gas.

 

In the time it took for all this happy banter, even BJ could have reflashed the truck to either confirm or eliminate this item as a problem

Sorry - I do not agree that a stock tune can mask a legitimate, fundamental underlying issue in the "suck-bang-blow" cycle. There are far more similarities than differences even between stock and 87 perf - the engine still runs with very narrowly defined parameters - can't change the physics.

One key here is the symptoms's attributes - in this case, the allegeded 'R&B'. Bad fuel does not manifest itself with a rythmic loss of power, at only certain rpm's loads. BJ, are you not filling up at the same place typicaly - I know you are choosy with fuel quality. Only one occurrance in 36,000 miles? Same supplier? Hmmm.

Jest don' sit right wit me, is awl... y'all

Yer not usin' Seafoam on the sly, are ya? Would you even remember?

Good thread, gentlemen.

 

It can happen, even if you don't agree ya dumb Canook.

When I still had the defective injectors in my truck I would get a slight ping from time to time on the 87 perf tune that wouldn't happen on the stock tune. The stock tune masked the issue with my injectors. With the new injectors and short block the same tune runs without any pinging.

 

My '04 does this occasionally. When the engine is warm, I shut down then restart after a few minutes, with light pressure on the throttle (just enough to get it moving) the truck will surge rhythmically as it moves forward for as long as I hold the pedal. Letting go or pressing harder stops it.

It was really bad when I bought the truck back in '04, a PCM relash fixed it (along with a tranny downshift problem, or lack of actually). It's recently started to come back although nowhere near as bad as when it was new and not often enough for me to worry about it. My surging happens with stock tune so I doubt a programmer is to blame.

 

Not saying this is related blue, but I think you are due for a TB cleaning anyways.

 

Bubba lives! I haven't seen him in ages!
Sorry to interrupt your thread their old man. Seems like you just have a bad gas problem, this also seems to be a trend when people get to be "over the hill"

 

Well, since I'm not "over the hill" yet, that virtually eliminates that problem!