Inconsistent Starting

**CNorell145** · 05-25-2014

After the engine rebuild, the car started with the high revs, as I posted before. The second and third time I started it, it turned over immediately, didn't have to give the car any gas, and it idle'ed like a champ. Every subsequent time after that, I have to give the car gas to get the engine to fire up, and it idles bouncing between 600-1300 RPM, occasionally trying to die.

The only things I can come up with as possible issues are EGR, TPS, and IAC. Do these sound like likely culprits to you guys? And why would the car start fine twice, then go back to not running correctly? Very weird.

**Scottydoggs** · 05-25-2014

start with vac leaks searching. move the vac lines when you spray them. spray the evap, map sensor, and around the TB gasket and its linkage. also the egr tubes. hit all that up.

if the TB has not been taken off and cleaned do that, make sure the sides of the butterfly are clean as well as the inside of the TB back side and where the flap closes.

**02NavyBlue** · 05-25-2014

egr, iac, and a sticking throttle cable/valve can cause that. Well egr could cause it to run very badly, just encountered this on a buick park ave yesterday. Sounds like a vacuum leak though, but intermittent? Seems unlikely. No codes? Maybe let it run and drive it a bit and the computer may throw a code.

**CNorell145** · 05-25-2014

Do you just clean the TB with carb cleaner? And it has not thrown a code yet, but it only ran for about 5 minutes - the alternator went out somehow during the process, may have spilled coolant on it, so the car died quickly running of only battery.

**02NavyBlue** · 05-25-2014

You should use TB cleaner, not necessary on gm tb's though but recommended. I use a small brass wire brush to clean. Always remove the maf sensor, you need security torx for that.