Engine sputters and stalls - '95 Transport 3.8L More Details Inside.

[yellowfiero]

My '95 Transport has been fairly reliable until this morning. It sat in the garage all night, ran fine last night. This morning, I cranked to get my kid to school, and it sputtered and stalled. Tried that half a dozen times and gave up.

Now its after lunch, and I tried it again, same thing. The funny thing is that if I rapidly and furiously pump the gas pedal at start-up, I can make make it run and keep running (as long as my leg can keep pumping), albeit revving up to 2000 rpm, then down to a sputter and back up again! The minute I take my foot off the pedal it will stall. With the key on, I can hear the fuel pump buzzing. The tank is full of gas. Sometimes when I crank and it stalls, I can hear a pop through the air cleaner (I think) - its definitely not through the exhaust.

Edit: No Check Engine light if I leave the key "on" (engine stalled).

Some history, it got a brand new fuel pump / filter last year about this time, I changed the air filter about two months ago, and it has had regular oil changes.

Any thing you guys want me to try, let me know - I'd like some direction before I start yanking things! Thanks!

[LMP]

It sounds like the MAF sensor quit. Pumping the throttle uses the throttle position sensor (TPS) to sense rapid throttle changes and that injects fuel, just like the old carburator fuel pump. You have no MAF code because the problem did not happen while it was already running. There has been a case where the 12v supply to the MAF sensor was lost because of corrosion at the large connector near passenger side suspension tower. At least, test for 12v supply to MAF..the pink wire.
www.avigex.ca/xport/maftest1.jpg
www.avigex.ca/xport/maftest2.jpg

[yellowfiero]

Originally Posted by LMP

It sounds like the MAF sensor quit. Pumping the throttle uses the throttle position sensor (TPS) to sense rapid throttle changes and that injects fuel, just like the old carburator fuel pump. You have no MAF code because the problem did not happen while it was already running. There has been a case where the 12v supply to the MAF sensor was lost because of corrosion at the large connector near passenger side suspension tower. At least, test for 12v supply to MAF..the pink wire.
www.avigex.ca/xport/maftest1.jpg
www.avigex.ca/xport/maftest2.jpg

Well, your hint did it! Turns out some inspection revealed that the tube that goes from the egr valve up to the intake was dislodged at the intake, creating a leak path for air. I pushed it back in (there was a o-ring that seated), and that did the trick! Your though on the MAF sensor was right on. Thanks LMP.

[LMP]

Funny...I had a similar problem with my late Dodge Omni..may it rest in peace...or in pieces...and I resolved to remove all of this EGR contraption and plug the holes....and the one thing that turned out to be an exact match for the threads in the manifold (after I removed the tube fittings) was a spark plug.. ..so others could imagine all sorts of technical reasons for seeing an additional spark plug at such a place...