My '88 (302 EFI C6 AT) stalled on me as soon as i pulled out of the driveway. Wouldn't restart then. I let it sit for 5 hours, then primed the fuel pump & it ran ok on the back tank, but stalled on the front tank when I hit the gas. I figured it was a problem with the front tank's pump.

Started it today on the rear tank, it choked & stalled as soon as I hit the gas. Same on the front tank when I gave it gas. Ran the EEC-IV codes, no current ones. code 33 for EGR was in the continuous memory codes. No other codes given.

I checked the fuel pressure at the schrader valve, was 40 PSI with the engine off, 35 PSI with the engine running. I started thinking it might be the timing, so I let the truck idle to get up to temp for a few minutes. When I came back out, there was fuel pouring from the front gas tank filler (I would guess at least a quart leaked out). Any ideas of what is causing this??

-Chris

 

Nobody has seen this?? My only idea is to start at the fuel filter and work backwards to the high pressure pump, then the dual function reservoir and hope I find some blockage that allows enough fuel for the engine to idle but not rev very high without stalling. Any other ideas are welcome & appreciated!

-Chris

 

Sounds like a faulty valve in the DFR. The diverter sounds to be stuck about half way. Allowing fuel to return to the wrong tank and not enough flow to the HP pump to keep engine running. With key on, engine not running, try tapping on top of DFR with a rubber mallet and see if the valve will seat. If it works, replace the DFR.

 

OK, just got back from my honeymoon and started working on truck again. I tapped the DFR, didn't help the stalling problem. I switched tanks several times to see if maybe the valve in the DFR would seat on its own. This worked, and the truck ran fine on both tanks. Later that night, I was idling at a stoplight and started smelling gas. I looked out, and the front tank was overflowing again (I was running on the rear tank). Even while I was driving, gas was flowing out of the front tank's filler hole and running down the side of the truck! I know about the faulty check valve issue in the front tank, but I am wondering if my problem lies in the dual function reservoir. I had a full back tank, and about 5 gallons in my front tank. 30 miles later, my front tank is full, and my back tank is down to about 1/4 full. If I let it idle in the driveway, it runs fine if it's on the front tank. If I idle on the back tank, after about 30-60 seconds, the front tank starts pouring out through the filler neck opening. Sooooo, would a bad check valve in the front tank allow THIS MUCH fuel to be swapped into the front tank??

 

Sounds like the DFR. I had a similar problem with gas pouring out the front filler hole, but not the stalling problem. In any event, I changed the DFR (about $80.00 at the dealer) and have had no problems since.