My TBI 350 seems to have developed a problem -- once it warms up, it won't idle. When the engine is cold it idles fine, then when it gets hot, the engine will die if I take my foot off the gas. I replaced my idle air control valve but that didn't help at all. It was running fine until about a month ago. Any suggestions what I might check?

Thanks!

 

codes?

 

hmmm sounds like MAT Sensor

 

Ok I did some testing this weekend - here's what I found:

- no error codes from the ecu
- I found the IAC bypass procedure on this board and tried it with the engine warm - idle was TERRIBLE. Wouldn't even run unless i put my foot on the gas.
- hooked up my ALDL cable and did some test runs. I'm running vortec heads and intake on the stock 350 bottom end but am still running the stock ECU program -- my BLM values are all over the place so I think it needs a custom tune...

Haven't messed with the MAT sensor - maybe it's bad?