poor running 454 TBI AGIAN!

[Cowboy_Customs]

I am completly stumped once again. My 454 wont run for crap. It has a choppy idle, like it has a hot cam in it, no power, at 1/4 throttle the RPM is up and down a couple hundred RPMs ( not while driving )

This just all of a sudden happened, during a valve cover change on the passenger side. I have checked and replaced all sensors as needed. New fuel filter, new BOSCH fuel pump, New Injectors (Venom from summit, I dont replace, I upgrade) Plugs, Wires, Coil, Cap and Rotor, ALL MSD, AC Delco plugs gapped at .35. Distributor replaced in march. The crap advance auto parts brand ignition componants crapped out badly (no money to buy good stuff at that time) Timing checked.

I dont understand, with 2 original injectors (193K miles) it'll be driveable, 2 foot at a red light, but driveable. one old one new injector, same thing. 2 new injectors, not driveable, NO power.


I burned 50% of my right arm hair off tonight because of a huge back fire through the intake, (havent checked my eyebrows yet  )  The motor loaded up, and refused to burn the fuel, and BOOM! This dang thing will not burn the available fuel, old injectors or new.

[TexasRed]

What about the PCV valve? Also, is the EGR acting correctly? Also, did you replace the fuel regulator in the throttle body? I think they have those. Maybe it's shoving too much fuel into it?

[VileZambonie]

Yes make sure the EGR isn't open first

[Cowboy_Customs]

Yeah, I regasketed and rebuilt the TBI/FPR a few months ago. And as far as the EGR goes, I did finally get a code 32 last night. But now the problem is, that EGR aint comming off! I have soaked and soaked and soaked the studs/nuts for weeks prior to the valve cover change. Im going to have to do a whole manifold just to replace the EGR.

Isnt the Computer supposed to store codes?? It only gives me a 12 this morning. What gives?

Thanks for the help.

[VileZambonie]

#1 make sure there is no vacuum signal at the EGR valve. Pull the hose off with the engine running.

#2 try to manually operate the valve by pulling up on the diaphragm with the engine running. It should run worse or stall.

[Cowboy_Customs]

Thanks for the help. I did do some checking and found that the controller isnt functioning correct. The EGR diphragm is good and functions, thank God, that thing isnt comming off either. The truck runs soooo good it is unbelievable, power, minimal blowby now, and the exhaust is quiet too!