YAGMTBIIQ! (Yet Another GM TBI Ignorant Question) (1 Viewer)

[Diesel Wannabe]

OK, I have been chasing Gremlins (demons, not the cars) in my GM TBI converson on my 2F for about 4 years now - on and off of course. Today I dropped in another TBI unit to see if that would help. The cruiser started and idled just fine - finally! But then my brother noticed that the high pressure line had a leak. We cut the engine and I tightened the hose clamp that had loosened during the TBI install and let the gas evaporate - I was ready to go for a drive! BUT, now that the fuel leak was fixed I had the same lousy/non idle that I've been fighting for so long.

Sooooo, here is the latest ignorant question of the day. There are two fuel fitting on the 4.3 TBI. One has a larger fitting and takes a larger pipe, the other is obviously smaller. I've never had any instructions and have never owned a GM TBI vehicle, so I assumed that the larger line/fitting is the intake and the smaller line is the return. Now I am second guessing that decision. Anyone know for sure???


TIA

 

[lone gunman]

i dont know if this will help ? i found it while looking for stuff on my TPI install. http://www.rowand.net/Shop/Tech/GMTBISwap.htm there is a couple of pages of TBI stuff, good luck!

 

[Poser]

Big fitting is in, small is out.

 

[69fj4069]

Sounds like your pump is putting out too much presure causing more fuel to enter the intake with each pulse of the injectors and flooding the engine.

 

[too tall]

fuel pressure regulator? Are your injectors for a 4.3 or a 5.7? Do they have a nice aspiration pattern?

 

[enj0ii]

make sure your return line is not restricted also, and your fuel system should not be pressurized. both will cause it to flood. is it drivable?