1987 V30 Flooding on start

[Dadam2786]

I have a 1987 V30 EFI with 350 flooding on start. Recently replaced fuel pump and relay. It seems to start if I hold throttle to the floor or will start if pulled. Any advice where to start?

 

[PrairieDrifter]

Pull the air cleaner and see if the injectors are leaking while not running.

 

[gmbellew]

I also think if the CTS goes bad they read way cold and that could be adding too much fuel. you can check the resistance at ambient temperature and see how it compares to the table of temp and resistance values in the GM emissions amd drivability manual.

 

[Sgt Gus]

I also think if the CTS goes bad they read way cold and that could be adding too much fuel. you can check the resistance at ambient temperature and see how it compares to the table of temp and resistance values in the GM emissions amd drivability manual.

Ooooo, I need to double ck that.

 

[gmbellew]

Pull the air cleaner and see if the injectors are leaking while not running.

the system is only pressurized during a few second prime at key on and while running. I'd put a dry papertowel under the injectors and key on for prime and check to make sure they are dry after the prime.

 

[PrairieDrifter]

the system is only pressurized during a few second prime at key on and while running. I'd put a dry papertowel under the injectors and key on for prime and check to make sure they are dry after the prime.

That's the extent of my tbi troubleshooting lol.

 

[Gander]

You don’t want to start it with the pedal to the floor. The ECM sees throttle position at startup and assumes that position is baseline.

There are so many different ways you could approach this, so many places to start checking.

First off, how original is the truck? Stock 350? Stock TBI? How long have you had it? Has it always run like this or was it OK and just started messing up? If you just got it, how long was it sitting up before you got it? I see you just replaced the fuel pump and relay. Was it running OK before that or did you replace those to try and get it running?

 

[gmbellew]

Starting with pedal down is actually “clear flood mode” and the injectors won’t fire or won’t fire as much. The ECM does use TPS voltage at start up as a baseline, but if the voltage is over a certain amount it doesn’t and helps clear a flooded condition.