1986 RO

I have a 1986 IROC with a 305 TPI car is hard to start when cold (sitting for about three hours) Engine starts then stumbles and dies until about the fifth try and it runs fine (Idle will fluctuate between 1700 and 500 breifly) Car runs great after this though. I thought it was the MAF, so i swapped with several other USED ones but got the same result but when unplugged the engine will run the same wont stall wont seem any different! idles around 600 (plugged in or not)...engine does have some codes such as...MAF code, coolant temp code, manifold air temp code.

Zepher

iTrader: (1)

Could be the Cold Start Injector or Cold Start Switch, or both.
Cold start injector is on the drivers side of the intake, it's the 3rd one from the front or back of the motor and looks different than the others.
Cold start switch is on the front of the intake below the throttlebody and has a connector just like the injectors.

1986 RO

I thought the very same thing and replaced all the injectors but still have the same issue...could it be the ECU?

Zepher

iTrader: (1)

you replaced all 9 injectors or just the 8?
And what about the Cold Start Switch? That is what controls the 9th injector and gives extra fuel when the engine is cold.

1986 RO

Yes that is all new....also I notice that when I unplug the MAF while the car is running it does not change the idle at all....the car runs very well when its unplugged and its warm. Also while drive the car will randomly drop RPM's...but then recover