TwitchZ28

iTrader: (3)

So here is the back story. Nearly a year ago I had a 228/228 .588/.588 112 cam installed with the supporting 255 walbro pump in my 2002 z28. The car has full bolt on's and long tubes, and a 3200 converter.

After the cam install I had it tuned, and all was well...for about 10 miles.

The car surged at low speeds especially in reverse. The rpms would flucuate and the car would stall out. The problem started small and got increasingly worse as the miles increased.

I went back to my tuner and he met me to adjust it. The car was at full temp the entire time he did the re-adjusting. When I left it was perfect.....for about another 15 miles.

The same issues have returned and are worse than ever. Low speed stalling, acting differently at different engine temps.

Things that make it better:
Resetting the tps
Pulling the battery cables and resetting the ecu.

Things that make it worse:
Reverse upon cold start
being in the temp range between cold and almost full operating temp
stop and go traffic(getting on the gas, then off and on the brake quickly.)
re-starts after being driven and then shut off for less than 10 mins. It will fire and instantly stall. Turn it over again and it starts and does not stall.


Things I have replaced:
TPS(Local auto parts store had a scanner that did live data and the tps was reading 14 at hot idle.) I don't know if that's volts or percent...but either is wrong so I replaced it.

Coolant temp sensor(no change, but I got it for free so no big deal



I am really at a loss. The car runs rich, stalls out at low speed after the rpms surge and fluctuate. It acts better or worse depending on the temp range it's in. I just can't figure out the issue. The tuner has seen it twice and it's been perfect when I left both times. It's re-learning something incorrectly...I just don't know what. This cam on a stock throttle body shouldn't be an issue. Any ideas guys?

2xLS1

iTrader: (25)

Without a datalog showing what all the sensors and controls are doing while running and a copy of the tune how can anyone know or help? Impossible.

TwitchZ28

iTrader: (3)

Sorry I had this posted in the internal engine section and was told to move it here.

I don't know **** about tuning or how the computer and sensors all work together. I am just hoping someone has experienced similar issues and could give me ideas to check.

I don't have access to tuning software or a tuner anymore.

Bowtie316

iTrader: (1)

Where are you located? Maybe someone on here is close to you or knows of a tuner in your area.

TwitchZ28

iTrader: (3)

Southern indiana. Bloomington.