Chevy & GMC Vans

Thanx astronut , but no MAF on a TBI & motor mounts are fine .

Skip I know you guys have practically rebuilt that whole engine...I'm too tired to re-read the whole post so I'll just throw this out - how's the oil pressure sensor, and the wire coming off it? also, if it's like my '89 it's a single wire sensor requiring thread contact to make ground. Is it getting good ground? If the ECM thinks the oil pressure is hitting zero it cuts the power to the fuel pump.
If I recall correctly, you guys tested the fuel pressure, what psi were you getting?

its not anything cutting power to fuel pump cuz you can feather the gas peddle to keep it running . ..

its gotta be TBI related , air fuel mix or a vaccum leak we can't find , cuz thats what it acts like . but with putting a different TBI on it who knows , it acted the exact same way after the other TBI was put on so now ..........
#-o #-o #-o #-o #-o ](*,) ](*,) ](*,) ](*,) ](*,)

if it wasn't $325.00 for a dizzy & carb thats what she'd be running on right now !!!!

map sensor?

all electrical components check out fine with a scan tool.

I am just throwing these out there...

Any chance you have something wrong with something live burned out valves or piston? Not even sure if something like that would cause this running condition.

What about the dizzy gear being stripped out? A buddy at work had a 96 S-10 blazer that died one day and it was a stripped plastic gear on the bottom of the dizzy.

Check the wiring from the ECM where it goes through the firewall right near the dog house and crosses over the valve cover. Look very close for burned/melted wires. Saw this in a 93 Astro when it just died one day...it was blowing ECM fuses though.

V8 Time!!!!

have done a compression test , all cylinders are great 120 to 122 psi .

burnt valve i highly doubt ,cuz theres no tell tale signs of it , but we;re not taking the heads off to check till its a last resort


dizzy was checked over real good by my buddy carlos when dennis changed the intake gasket .

wiring at the comp , from the comp , thriough the firewall &all across the motor &at each connector , all in decent shape ..

v8 isn;t necessary , this motor when running runs fantastic . & with a TBI v8 swap , you'd use all the comonents from the 4.3 & would probably wind up with the exact same problem !!!!! your talking about the Fisher luck here DEan . nothings gonna be easy , it jusy wouldn't be right if it was !!! ](*,) ](*,) ](*,) ](*,) ](*,)

Now taking donations for a v-8 swap. Any and ALL parts would be appreciated

you check the pickup coil in the dizzy?

yes, every electrical componant in the dizzy & on the motor has been replaced with new or known good parts.........

It sounds so much like the egr. Have you attempted to totally block the egr port? Take a piece of sheet metal the basic size of the egr port and use it like a washer between the egr and manifold. That will eliminate any possibility of the egr valve, solenoid, etc. The EGR should only open up at cruising speeds. If any of that exhaust gas is getting into the intake manifold at idle, it will die due to a lack of oxygen.

It sounds so much like the egr. Have you attempted to totally block the egr port? Take a piece of sheet metal the basic size of the egr port and use it like a washer between the egr and manifold. That will eliminate any possibility of the egr valve, solenoid, etc. The EGR should only open up at cruising speeds. If any of that exhaust gas is getting into the intake manifold at idle, it will die due to a lack of oxygen.

no we haven't , will have to try that . what would cause that condition / a cracked manifold maybe , or warped ?

I know this wont help, but I had a s10 doing the exact same thing, I put everything on there you could replace.It NEVER would run right,so I pulled the motor and put a carbed v8 in it.To this day I still wonder what it was...

need some ideas guys , this thing can't beat us , its got to be a fixable problem .

Bill's right, try blocking off the EGR with a plate. You have nothing but a gasket to lose...