I'm at a loss, so hopefully I can get some input regarding my issue. 2002 GC Sport, 3.3 L.

Wife was on a road trip yesterday when the engine, while cruising at 75 mph, suddenly shut off as if the key had been turned. She stated their was no hesitation, bucking, etc. indicating a problem or that a stall was coming. Luckily she was able to safely get off the highway. Van would crank but never restart - no codes. Thanks to AAA (worth the money when needed) was able to get it home.

After getting it home, I of course attempted to start it. Plenty of battery and cranking power - no dimming of lights or diminishing crank, so pretty sure starting system was fine (outside possibility of no spark). Seemed like it was going to start when doing short bumps on the ignition, but holding ignition just never attempted to even start.

After several attempts to start I finally got code 1282, so replaced fuel pump relay and reset PCM. Still nothing - plenty of crank, no start. Could smell gas as I intentionally attempted to flood it.

Kept attempting to get it to start, with and without pressing the accelerator and eventually got it to. Had to keep gas on it or it would die. Tried again, giving more gas and got a backfire at about 2k rpm or so - immediately stopped and checked for a new code, but nothing. Restarted, backfired again, rechecked for code but again, nothing.

Restarted, and it would now idle without applying accelerator. However, idle was very rough and would slowly cycle between 400 and 900 rpm. Applied accelerator and no more backfire, but when letting off would drop to about 400 and than slowly come up to around 900, but I still feel like the idle felt wrong when it would stabilize around 850. Seemed to run "better" after every restart. Have not road tested as off yet to avoid possible damage under load.

Still have no code, so now I am down to possibilities:

1. TPS fault that isn't setting a code.
2. IAC fault/dirty with no code (+ dirty throttle body)
3. Faulty Fuel Pump or pressure regulator, clogged fuel filter.
4. Crankshaft or Camshaft position sensor. Replaced the crankshaft sensor 2-3 years ago.
5. Fuel injector harness - melting issue or otherwise.
6. Bad PCM
7. Faulty coil pack (replaced ~ 2 years ago)
8. Electrical issue
9 Other

While I know how to assess most of these issues, would rather start at the most logical point based on the symptoms. I imagine that with the prevalence of these vans that someone will
have experienced something similar and can suggest a plan of attack.

Thanks.

UPDATE:

So wife just got home and after some probing, it appears that the beginning of this issue differed from what I stated above. While doing 75 mph with cruise control on, she noticed the speed starting to decline and the rpms dropped to 0. Cruise control did not turn off according to her. After making it to the side of the road, she stated that the engine was still running, but tachometer still read 0. While still in drive, she gave it gas, but the vehicle would not move at all and tach remained on 0. At that point she shut the van off and from that point it wouldn't restart.

Very odd, but also leads me to believe the fuel system is fine since engine remained on. Hopefully this will generate some new ideas. Although I haven't road tested the vehicle since getting it running again, I did drive it into the driveway to get it off the street. So, leads me to believe it is not tranny related as I have already been through the tranny imploding before (plus no 700 level codes). Just a reminder: tach has been fully functional since getting it running again.

 

Update:

Just attempted to start it and it wouldn't. Tried with and without pedal, but nothing. Only tried a few times before bumping it as the starter wound down from last attempt and fired up. Ran a little rough before settling down at 850. No backfire. No codes.

I did hear what sounds to me like stuff rattling around, but not very loud. Almost sounds like the catalytic convertor when inside the van, but can not be sure it really was coming from there as I cannot pinpoint it when outside the van. Also noticed a faint melting plastic smell when under hood, but was hard to track as faint as it was.

 

Check fuel pressure with a pressure gauge. May need adapters if you don't have a test port on the fuel rail. You can sign them out from parts stores. Should see 55 psi.

Short of that try starting with starting fluid sprayed in the intake. If it starts right up then dies, it's a fuel problem. If it doesn't try to start it's likely spark related.

 

No codes has me curious as I have the same van.
Standing by for the outcome.

 

See update (revised info) in original post above.

 

Will check the fuel pressure, but based on my revised original post I am starting to lean towards a TPS problem. In searching, I found that a lack of throttle response is indicative of a faulty TPS/throttle body. At least it is easy to check and can be stricken from my potential culprits.

 

I think you may have hit the nail on the head Cougar. Rented a fuel pressure gauge. However, turns out the adapter for GM/Chrysler vehicles was broken - go figure. But in a strange twist of fate, it lead me to an observation: when attempting to alleviate the pressure manually I got nothing! Not a drop. Nothing. Nada.

So this indicates to me that the fuel pressure regulator is toast. Going to go by my favorite local mechanic who I send occasional work to and see if I can borrow his kit. Although I think I am onto something, I still can't logically put a failing regulator and the loss of RPMs and unwillingness to go as stated in my op though. I can see how it explains the difficulty starting, but not the other symptom.

Assuming it is the regulator and it is attached to the pump, would it probably be best to just replace the entire pump assembly since I am approaching 200k miles and wil already have the tank down?

 

After some further diagnosis, am rather positive the fuel pump is the culprit. Pressure, both before and after running the engine, is absent based on no fuel leaving the pressure relief valve. Plus, I noticed that the pump does not kick on every time it should.

Thus, I am in the process of draining the tank. However, as I learned the hard way, cannot get a siphon hose into the tank as it screened off. So, in an effort to return useful knowledge to the community, I wanted to convey a way to drain the tank without siphoning. This will only work if the pump is at least marginally working, but will take awhile and can drain the battery down if you have a lot of fuel to move or the pump is very weak:

1. Remove fuel pressure relief valve cover.
2. Using an appropriate tool - hemostats in my case - remove the shrader valve from within.
3. Attach appropriate hose to fuel pressure relief valve housing and secure with clamp - careful not to crush the valve housing or threads.
4. Run line to another vehicle's tank or appropriately sized fuel container.
5. Remove fuel pump relay.
6. Run a wire from positive battery terminal to pin receiver 86 of fuel pump relay position in ipm and watch fuel pump out! No need to have the key on as this bypasses the entire system and applies 12v directly to the pump.