Eng. died suddenly, started soon after. Need quick opinions.

[RidgeRunner]

'93 Sunbird
3.1L
5spd
224k miles

~40 degrees, light flurries.

Started out from my apartment. Got a couple miles up the road. Stopped at a light. Turns green, I take off. Pulls fine through first, I shift to second, and BAM! it just quits running. Kaput.

Roll off to the side of the road, and try to restart. No fire. I think to myself the timing has jumped. I can hear the starter slowing down as I crank, I think it's time for a new battery too.

I sit a few minutes longer, and try cranking again. Finally, it spits, sputters, and finally roars to life. Drives fine afterwards, like nothing was wrong. Scratch timing.



What the #@$& could have caused it to just die like that? I take off on a 1,000 mile round trip starting tomorrow. Are EFI vehicles suceptible to "carburetor ice" or anything of the sort? It has a 62mm TB, so there is no TB heater. I'd hate to end up stuck on the side of the road in the middle of nowhere swamp-ville. Especially in cold weather.

[SappySE107]

RE: Eng. died suddenly, started soon after. Need quick opini

Not likely that its got an issue with ice in the TB. Check your ground wires and battery connection. Those are the most likely for an intermittent like that as far as I can think of. Possible that the computer is going south too though that usually does something else screwy too, like SES light, no codes (no 12), or no speedo. Id say loose wire as my guess.

[RidgeRunner]

Was suggested to me via IRC that it might be the crank position sensor. Likely culprit?

[SappySE107]

Possible, though why would it be ok now? If there are no loose wires, then its more possible that its that.

[RidgeRunner]

Can those not fail intermittently?

Eh, I'm gonna see if it'll make it the 200 miles home, at which point I'm borrowing something else to make it the other 300 miles or so to Cape Hatteras.

This car is becoming an annoyance... I want a Solstice.

[SHOoff]

Low oil pressure

[RidgeRunner]

Can't see why it'd have low oil pressure during a ~3500rpm shift. Oil level is not low.

[SHOoff]

I know it's a common thing for that to happen to the Quad4 cars. They'll spin a bearing and the oil pressure will suddenly drop. The pressure switch then turns off the fuel pump and the car dies. What ends up happening though is people will restart their car and tear the crap out of the engine.

[Scott205]

My first guess would be the ICM. I have broken about 5 of those on my 90 Lumina 3.1L. The last one ran sometimes, replaced the Crank Sensor, ran for awhile, stoped. Replaced the wiring from the Crank Sensor to the ICM, ran for awhile quit. Finally took it to a friend to have it diagnosed becuase i was getting intermittent readings of what was bad. ICM came up bad, replaced been running since. But nothing wierder than it running from 5 minutes to 5 hours and suddenly quiting like that.

[Manitcor]

the CPS is a good culprit, the wire to my CPS was laying on the header and the seathing on the wire had melted however the connection was still there, intermittently the wire would make contact with the header or someother ground point and kill the car or keep it from starting.

Might as well check the wire for any frays, rips or breaks.

[Juglenaut]

This is a 3.1/3.4 ECM, I believe it doesn't have provisions for a oil pressure safety switch.

Check resistance at the primary side of the coils.

Defective Coils out of the box can blow a ICM if the impedence is to low.

Check continuity of the negative primary side of the coil plug to ground. Tap the ICM while doing it.

Check continuity of all leads from the ECM (Disconnect ECM plug) to the ICM.
Vary by model, make, year.
White, Tan/Black, Purple/White, Black/Red> To ECM
White tach signal or Negative primary.
Black/white ICM ground leaded
Pink/Black or pink Hot in run.

These colors vary it seems by even mileage, so white may appear tan, tan may appear like white would if it looked tan, purple may appear black, red may appear pink and so on.

And as well as the well know yellow and purple..I still don't know why reversing these makes an extended harness work.