Hey guys....long story made short: Tuned this guys 5.3 Silverado with a Diablosport Tuner. The truck runs like a beast from dead stop to 80MPH....then at 80MPH the truck will surge and buck like it's missing. You can hold the throttle to the floor and it will surge and buck but not go any faster than 80MPH. What's the deal? Do I need to go in and tweak something or is there somehting I'm not aware of with the Diablo Tuner?

 

And judging by all the responses on my thread, I can clearly see that there is a lot of input in this forum.

 

Could be a lot of things. Maybe the plugs don't like the extra spark advance. Maybe the fuel pump is maxing out. Next time you do a run, use the pred. to monitor live data and see what the O2's are reading when it surges and misses.

He had no issues at all until after the Diablo tune correct?

 

Correct. It ran fine before the tune. And before the tune he had Gibson Shortie headers w/ Gibson catback, K&N FIPK...and a lousy Jet Module. So I removed the Jet Module and did the Diablosport 93 Tune...and now this happened.

I didn't think about making him upgrade to the AC Delco iridium plugs....he's still got the regular 41-901 Platimun plugs in it.

Thanx for your input Slow.....

 

Hey Torque...it's the weekend man! Drinking to be had.

So, you installed a Diablo tune and then immediately had problems? As 1Slow suggested, monitor the o2's and report back their voltage when it's bucking. Bucking is usually affiliated with lean. The diablo tune...is it new? What's the story behind it? But let us know what those plugs look like and what the monitor says. I can't imagine a plug change would be needed, unless you went FI. And even then, a little boost(5 to 7) is okay on stock plugs.

 

Thanx man.,..I'll check this out and repost my findings.

 

check the speed limiter?