ITSAV

iTrader: (1)

ok, so ever since this recent build up, I have not been able to line up a start up issue. I start it up, and it starts stuttering, if I pump the gas a little bit and keep it above 1200 RPMs it'll stay going, and in less than a minute it lines itself out, and stops doing it....than it runs fine. If I dont pump on the gas than it'll stutter real bad, and bob between like 200 and 1200 RPM's. Sometimes it will die, sometimes it'll pull itself up, and run....

So last night, we were working on the tune, trying to get that issue lined out....We eventually realized the guy that had tuned it had done some rather strange things with the tune...that could explain the issue. So after working on it for the next couple hours, we thought everything was lined out...but went to start it the next day, and the stuttering is going again (it usually only happens with a cold start). So upon looking at it further, I notice my TPS sensor is off it shows 11% when my foot is completely off the throttle, so I was thinking that maybe causing the issue....but can't seem to get the TPS to "relearn" I did the whole, leave car in run for at least 3 min, turn car off, start it, leave running for 30 seconds, turn it off, and start it again, and its still wrong....


Any recommendations on getting the TPS corrected?

serik21

Maybe your tps took a **** that's why the tune was funny to begin with. Trying to correct the tune due to a faulty sensor will always result with issues.

DMM

It could be a lot of things...post your tune and mods and get more eyes on it.

RADEoN

iTrader: (12)

11 when completely off the throttle really doesn't sound too out of the ordinary...

ITSAV

iTrader: (1)

ya, we didn't notice the problem with the TPS till after we di some changes to the tune.........but i def think the original guy tried to tune around the issue, making everything look weird

DMM

Depending on what cam you have and what the base running airflow is set to, that is perfectly fine. I am just now starting to tune my cam+heads and I am at 10% TPS at idle (at 875 RPM target idle speed) as well...



That's why I said...post your tune, post your mods. There is a lot that can be misinterpreted in a tune. FYI - IIRC I was at 3% TPS with everything stock.

RADEoN

iTrader: (12)

the larger heads and cam duration command much more flow, so the computer opens the TPS that much more. Tomorrow morning I'll let my car idle and check the absolute TPS for you, but IIRC, it was 9.8 on average.

07CTS-V

iTrader: (6)

That tps number will change with your base running airflow numbers. There are calibrations for startup airflows and startup modifiers. Those are where you should look along with the timing and fuel modifiers for lower coolant temp ranges etc.

ITSAV

iTrader: (1)

thx for the info here guys...ive been without internet at home, so just seeing this....will prob go out with the laptop tomorrow, and take a look and get the info requested