Exhaust coming out intake. Stalling. Please help

[ipeelscats]

I am having an issue with my 98 QX4. My girlfriend informed me that the truck had been misfiring on her way to work. I pulled the plugs and they looked bad so i replaced all of them. I also replaced the wires, cap, and rotor. The truck ran great when I finished and I took it for a nice long drive, no issues. 3 hours later I try to go to the store and it stalls in the driveway. I checked the wires and they are all tight. The cap and rotor still seem to be ok. So I thought maybe clean the MAF. When I took the first bolt out of the airbox I see white smoke, it smells like exhaust. I am at a complete loss on what this could be. Anyone ever had a problem like this?

[ipeelscats]

So im pretty sure the exhaust in the intake was due to a backfire when it stalled. I managed to get it to start after it cooled down. If i keep the RPMs up around 2-3k it runs great. Around 1.5k it will stall. I am thinking egr is clogged due to her driving it with the bad plugs. Does this sound reasonable?

[ipeelscats]

Update: removed egr and regulator, sprayed with a healthy dose of throttle body cleaner. Cleaned with a tool and compressed air, and reinstalled. No change. It seems like the truck is starving for gas. is there a fuel pressure regulator on this vehicle? I am running out of ideas for things to check. The truck will run smooth as butter for ~10 seconds if I let it sit for an hour or so.

[Leo1998]

Do you get to a stop light and it suddenly wants to die? but if you keep your foot on the brake and gas to keep the rpm's up you can take off and it will drive fine until the next time? If so, then it's your MAF sensor. I tried to clean mine (MAF) with no change, then replaced it and everything was good.

[ipeelscats]

I drove it earlier today and it ran fine. After it sat for a few hours I have been unable to get it to run long enough to get out of the driveway.

[Leo1998]

Yeah mine didn't do that. I could at least drive it around, just with one on the brake and one on the gas. Any codes? If you start it up and unplug the MAF and it stays running then it's bad, if it dies? it's good.

[ipeelscats]

No codes. I have not tried power braking. I'm thinking is a fuel delivery issue. Unfortunately I don't have the tools to test for that. Probably going to have it towed to a shop in the morning. Thank you for the input.

[Leo1998]

Good Luck and I'm going with bad Distributor for $200, just because everything I have read about misfires, stalling and not starting on a VG33E seems to be the Dizzy. Let us know what's up, curious about my theory.

[ipeelscats]

The misfires where caused by the plugs that where replaced yesterday. They where factory and a few had cracked. I replaced the parts with OEM plugs and wires. There are no misfires now, just this stalling issue.

[ipeelscats]

So after messing with it this morning I noticed that when left alone with the key in the off position, it will not crank. If I leave the key in the on position for 5 minutes or so, it will crank and run for ~30 seconds before stalling. Starting to sound like a fuel problem to me. Also, I opened up the distributor and removed the plastic cover on the inside looking for metal shavings, everything looks clean and clear.

[ipeelscats]

The truck has been picked up and taken to a trusted mechanic. I will update when they find the cause of this issue.

[Slumpert]

First the issue with or distribs is that the carbon dust from the cap rotor will migrate down deep inside where I guess it shorts out stuff... Far below the plastic cover.

Fuel pump / regulater are my guesses.

[ottofalcon]

Did you move the distributor when you replaced cap and rotor?

[ipeelscats]

I had to rotate the button with the starter to get to the screw. I did not turn it by hand.

[ipeelscats]

Truck came home today. It turned out to be the distributor.