Mystery Death???

Went for a drive this past weekend and a few miles from civilization was coasting along the path, very slow, no throttle, in 3 (auto) when the dash lights came on, engine died. Cranked fine but no start.

Most recent mod was a "long range" fuel tank. Uncomfortable about fuel pump changes but its been running fine for about a month, no hiccups.

Pre-event, drove about 1.5 hr, stopped for lunch about 1 hr, then ran about 20 minute till event. Couple puddles but no splash. No hiccups.

Cheched engine bay, no water, no wet, dist looked completely dry, no hoses/wires obviously off. Twisted "coil" wire around, seemed tight and dry. Checked fuel pump plug. looked connected. Turned on ign but couldnt hear the FP run. Checked shraeder valve on fuel rail, good press and fuel came out. Disconnect/reconnect FP plug, looked completely dry inside. Checked fuel cap, no overpressure when loosened (did hiss when filling that am).

Total time about 5-10 min, attempt start, OK, ran fine rest of day and all week following. Never had any similar issues before.

Obviously I would like to figure this out to regain confidence prior to future trips. Any Ideas?

The fuel pump sound fishy, but if you have pressure at the rail then that dosen't sound likely. I had a cam shaft sensor go out on a 92 I had. It was a manual and died driving down a steet doing 35 or 40 in gear. I pulled into a parking lot and cranked it with no luck, let it sit a bit and then craked some more and it started after some craking. It ran fine for about a month and then did the same thing again. Finaly the third time I couldn't get it to start. Thought it was the fuel pump. I didn't have time to mess with it myself and had it towed to a mechanic, and it was the cam shaft sensor. $400 bucks for a part I could have replace for about $100 if I had known what it was. I now have an 01 with the distribiterless ignition so I don't have to worry about that again.

Trash in the fuel?

did you take a look at the cps sensor. when i bought mine it would crank but never start and i checked the cps with an ohm meter and it tested out fine but then the damn thing started ended up just being a bad connection. the cps sensor is by the number 6 exhaust port they seem to go out pretty often on the 4.0

lilwoody said:

did you take a look at the cps sensor. when i bought mine it would crank but never start and i checked the cps with an ohm meter and it tested out fine but then the damn thing started ended up just being a bad connection. the cps sensor is by the number 6 exhaust port they seem to go out pretty often on the 4.0

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Actually, the sensors themself don't go out all that often (but it does happen) - its the plug for the CPS thats trouble prone. Its right over the rear of the manifold, where the engine bay stays hot all the time. When your cps "fails", you can unplug it, spill a little dielectric grease in the plug and hook it back up - and it will keep going until it dries out again.

>Trash in the fuel?

I would consider that since the new tank came with a (cheap) fuel filter that I didnt use, and would expect to pick up junk from install/shipping/etc. I planned to replace the factory filter after a month or so, such that it would collect all the possible junk and then be tossed. Putting the new filter in with install is kinda worthless since it will pick up junk immediately and you would then need to change it soon thereafter.

But the failure didnt seem like clogged filter or bad fuel. No running problems at all. No coughing, sputtering, etc. It did crank a hair longer on the successful start, but not much at all. And no subsequent running problems.

I will look into the cps (cam position sensor?).

Thanks for the input.

crankshaft position sensor, its mounted on top of the bell housing of the tranny pointing down on the flywheel. the plug should be located in the very back of the bay right by the #6 exhaust port also try to follow the wire to see if it was melted by the manifold.