TBI issues ????

[Missy Good Wench]

My 91 Burb has an interesting quirk.

It runs great most of the time. Now if I run it and then after its hot, allow it to sit for maybe 15 minutes or so and then restart, the thing will stall out, stumble and fool around for a short time and then all is fine again.

I am thinking maybe that the pressure regulator on the TBI unit is taking a crap ???


I have owned a few rigs with TBI but never laid a wrench on a single one so sort of in the dark with these things.

Fuel pump (Tank mounted) seems a long shot as the rig runs fine down the road. Its only after a hot shutdown and then a restart that it does this thing.

Any info would be great.

Dont want to spend $$$$$$$$$$ swapping parts for no good reason.


Missy

 

[btfarm]

When's the last time you put a serious amount of injector cleaner in the tank and ran the pi$$ out of it? That's usually the first place to start with TBI or port type for that matter. I had that issue with an old 4.3 Blazer. It was gummed up and the above cleared it up.

 

[Missy Good Wench]

Likely would not hurt it to dump in a couple cans of SKUNK PISS and see.

The only time it does this is right after a Hot shut down and short sit.

If I let it stand overnight and do a restart its fine. Will run flawless all day long until I shut it off and let it sit HOT.


Missy

 

[btfarm]

There is a higher pressure (richer) fuel tune when cold vs hot. That's why it flows ok cold. In any case, it never hurts to do a 'cleanout' run... even if there are other issues.

 

[Missy Good Wench]

Will give it a go and see what happens.

At 229K on the clock it certainly could be skunked up badly.

Thanks

Missy

 

[6.2 turbo]

Could be vapor lock, winter gas is bad for that,try some premium,branded gas .

 

[jelawrfarms7]

map sensor and or idle air control

 

[WarWagon]

Grounds!

Injectors dripping after shutdown and flooding the engine or regulator gasket leaking causing same flooding?

Fuel pump failing - common part to fail and sometimes burns the connector at the tank as well as taking out the fuel pump relay.

Any codes?

How does the TBI look for wear esp where the throttle blades may hit the TBI boar?

What is the idle RPM hot and cold? There may be dirt built up on the IAC pintle causing low enough idle RPM hot to stall it out. They stall about 450 -500 RPM when they should be 650 or more RPM.

EGR failing leaking etc - esp a back pressure valve failure, in the EGR unit, causing it to go wide open with any vac signal is a common failure for TBI. Simply all kinds of weirdness - not running right from that.

Vacuum leaks including failing brake booster.

 

[trouttrooper]

this is a 3 year old thread revived from the dead.

 

[WarWagon]

Weak coffee this AM...

 

[btfarm]

Missy hasn't checked in since Mid December