Surging and touchy fuel pedal with new FU2 chip

Huckleberry · #1 Wed, June 20th, 2012, 05:21 PM

Just finished installing a new FU2 module. I have a surge even with the modified stock setting and it is doing it in all settings 1-6. The pedal has a slight dead spot off idle and then the truck launches forward. I also have a lot of black smoke on hard acceleration (3/4 throttle). My 6 positions are:

modified stock
heavy tow
standard tow
light tow
80 daily driver
whisper

The truck has just went through a heads up overhaul that includes the following:
H11 studs, Comp Cams springs, Smith Bros. pushrods, FF 250/100 injectors, regulated return fuel system, Stealth SRP1 HPOP, HPOP crossover hose, larger turbo, 4" exhaust. The EBPV has been deleted.

I have only driven it 11 miles. I have access to a scan tool. I am getting an IAH heater code (my truck is an early 99, but I installed a later PMT1 PCM). The early 99's did not have an IAH. I also have a PO238 Turbo boost sensor A circuit high and a PO478 exhaust pressure control valve high.

My IPR oil pressure at idle is around 500 give or take 25 psi. I also noticed the idle switch does not show "off" until .82 volts with normal foot off pedal of .59 volts. Could this be the touchy pedal problem?

Thanks for any help

Huckleberry · #2 Wed, June 20th, 2012, 05:37 PM

The surging is 100 to 150 rpm total. 600 or so to 750 or vice versa.

INFRNL · #3 Wed, June 27th, 2012, 08:24 PM

I take it your surging is at idle? I talked to Bill yesterday cause I am having the same issue along with a shift issue.

He has to relook at your files and make some adjustments. you need to get a hold of Bill. He explained what is going on, but I could not explain it myself.

Bill does have the ability to fix it. I am not sure if I got my rewritten tunes or not. Truck seems a bit better, but still some issues. I will need to recheck and call Bill to confirm that he had a chance to send the adjusted tunes.

Mine also has some weird idle issues when parking, stopping, and putting the truck into gear. Biggest issue is shift issues between 20-30mph. Torque converter does not seem like it locks up as it did with standard tunes. Now it only seems to lock up aster going into OD. With standard tunes, it seemed to lock up if you got on it and other times, but the truck really moves; thats for sure.