Not a Tahoe, but I need help with my '92 K1500 (TBI) please guys...

[ChrisAU]

I am rebuilding the TB and replacing the injectors.

I had a good shop in my area hook up a fuel pressure gauge at the TB and I watched it hold steady at just over 15 psi even during stumbles. My injectors have no come shape at all its more like a pulsing water hose on both sides.

 

[SunlitComet]

you seem to have a most righteous pump and some bad sprinklers for sure.

 

[AtomicHoe094]

if this doesnt fix the problem (TBI rebuild) check into your temp senders..

 

[SunlitComet]

temp sensors don't fix crappy spray patterns.

 

[AtomicHoe094]

i said if it DOESNT fix the problem, look into temp senders.. they tell the pcm its -40 degrees out which means the injectors are going to DUMP gas, its not going to have a pretty pattern when it dumps gas.

 

[SunlitComet]

It will still have a good pattern but pulse width would be longer.

 

[ChrisAU]

Yeah I'm thinking the FPR diaphragm and/or the leaky injectors are causing the high pressure.

As for the temp senders, both are new AC Delco units. That had crossed my mind though, if I still have problems after this I am going to swap the AC Delco one on the manifold for a Delphi one.

 

[gpracer1]

I had a 93 with tbi, replaced with a Holley tbi. Replaced the carb on my boat with a holley tbi. All three of them shower, there is no misting. It takes too much fuel to feed a V8 through 2 injectors to have a fine spray.
As long as it is even all around and not pissing a stream it's probably ok, especially if the other one is the same. They run about 11-13 psi stock I think.

 

[AtomicHoe094]

i was thinking 15 lbs is too high from the beginning, but some years are different with each other.. mine dont spray a fine pattern either on my 454 or 350.....

 

[ChrisAU]

Well a leaky diaphragm and/or injectors can cause high pressure.

In a functioning system the pressure is limited by the FPR first and then the injectors, if they were free flowing there would be no point in having the FPR.