88 Chevy K5 Blazer

[b_hatler]

I am having trouble after it warms up, driving at medium to high speeds. The truck just acts like it is running rich, or trying to die. It spits and sputters, backfires, it has the TBI stock 350. I was wondering if anyone has had similar problems, it is erratic does not do it all the time. Maybe the temp sensor? All suggestions welcome. Thanks

 

[diesel4me]

If its acting like a carbed engine would if the carb flooded or the choke was sticking shut too much,blowing black smoke and wanting to die at idle,and run rich and load up until it clears up under throttle,it could be the fuel pressure regulator...pull off the vacuum hose on it and see if any gas comes out of it--if so,the diaphram in it is ruptured and the engine can suck raw fuel into the intake thru that hose..................................................................................................it could be numerous over things too though--oxogen sensor,temp sensor,vacuum leaks,etc....those should set off the check engine light ...

 

[British Slave]

Temp sensor would be a good place to start.

 

[4xcrazy]

If its acting like a carbed engine would if the carb flooded or the choke was sticking shut too much,blowing black smoke and wanting to die at idle,and run rich and load up until it clears up under throttle,it could be the fuel pressure regulator...pull off the vacuum hose on it and see if any gas comes out of it--if so,the diaphram in it is ruptured and the engine can suck raw fuel into the intake thru that hose..................................................................................................it could be numerous over things too though--oxogen sensor,temp sensor,vacuum leaks,etc....those should set off the check engine light ...

When did TBI engines start using vacuum pressure to control fuel pressure?

I would check the fuel pressure though, the pump may be heading out onit, sounds like mine did when it started to die, then just ran like crap at any time, until i put a new pump in after replacing several parts,,, this was of course before I had a fuel pressure test kit.

 

[496truck]

When did TBI engines start using vacuum pressure to control fuel pressure?

Bah, he's an old school carb guy. Give him a break.