tbi problem

[mechanical1973]

just wondering how many others have run into this problem.

I have an 87 k5 blazer with the 5.7 tbi motor and automatic trans.
It constantly shuts off (mostly at low rpms like at a red light or stop)
No codes show up, but the vacuum gauge does indicate low vacuum at idle - it actually indicates "sticking valves" I checked for leaks by spraying carb cleaner but could not find any.

What I did notice is the return fuel line has a very bad kink in it just as it turns down the firewall. Not sure if this would cause this problem - from what I know, this would increase the fuel pressure in the system right ?

Anyway, if you guys have any suggestions or have come by this problem let me know. I'm close to dumping this tbi set-up and going carbureted.

thanks
nelson

 

[blazerguy 90]

Idle Problem

The first thing to check is the gasket between the intake and throttle body, next thing to check is the IAC, if its real dirty it won`t operate properly, you might also consider removing the TBI unit and giving it a good cleaning, there are several vacuum passages cast into the bottom of the TBI that can get plugged, also check your EGR valve, if its plugged or bad it can also cause the problems your having.

 

[clarkjw24]

i wish in one hand and shi : in the other one its great / butt what can u do efi is kinda junk on the old 350 gm made in the 1980"s i would go to a single plane carder carb off a boat

Yeah what he said. lol

I'll take that tbi setup off of your hands when you junk it.

 

[dyeager535]

So lets see...the fuel line return has a bad kink in it, and the engine has low vacuum. Thus, TBI sucks and a carb will solve these problems? Fail to see the logic here.

*Logic* says that you have two known problems, and fixing them can't make your problem worse.