Chilkoot

When cold, car will start and idle fine @ ~1100rpm. After a minute or two it stalls. After it stalls it will crank, and fire, but stall instantly once it catches. After doing this a few times it will crank, but wont fire until it's cold again.

It's not:

Fuel filter (replaced)
Fuel pump or ECU (no change with b+ and fp jumped, can hear fuel in the rails)
MAF (no change with MAF unplugged)

with heavy throttle while warm it will fire and rev like hell, but sounds ugly and rpms will cut out to near stall and jump back up intermittently, sometimes stalling.

I'm thinking the driver side coil dies when it gets hot, anything else it could be?

Plugs, wires, caps, rotors all replaced 3 years/20k miles ago during tb/wp job, coils are original @ ~150k miles.

Thanks all.

deanshark

Yeah it sounds like that coil is getting hot, it's common for the drivers side coil to do that. Try switching the coils around and see if it happens again.

PureDrifter

iTrader: (10)

there's tests posted for the coils and igniters. do them.

radiokilla

Check the coolant temp sensor or the thermometer. My engine would do that then I replaced the thermometer and it was fine.

PureDrifter

iTrader: (10)

thermometer

Chilkoot

Would that I could, but I've had very limited facetime with the car, as it didn't die at home. I've only been able to steal the girlfriend's car for about 4 hours worth of time over the past few days.

The good news is, from the 15 minutes I was able to stop by the car today, it seems that the driver's coil has completely died now, as it won't crank without throttle and when it does as best I can tell I'm only running on one (weak) bank.

Already picked up a new coil, I'll have all the time I need to install it tomorrow. Last one in town, a BWD, for $45. Decent brand? One will at least get it running, and I'll have to wait for the other to be delivered.


I've had pretty bad low RPM hesitation for the past 6 months or so, my best guess is that I've been intermittently running between 5-7 cylinders depending on what the coils could keep up with at any given time, and with one coil finally failing the other just can't keep a whole bank running at idle to keep the engine alive.

Oh, and I replaced the temp sensor a year or two ago, thanks to a thread I read here. Got a few MPG back out of it, and got rid of my white smoke at idle

deanshark

You darn Californians, you talk weird.
I think it would be "thermostat"

Anyway, Chilkoot, I doubt you will need to change the other coil b/c the drivers side is usually the one that dies and that's b/c all the heat down in that side of the engine.

Chilkoot

I'll let you all know how it goes.

And thermostat? They fail open, if it goes bad your temp sticks around 1/2 way to hot. Fixed that with the tb/wp 3 years ago

Chilkoot

New coil seems to have helped a lot, but she still cuts out. Now it takes up to a few minutes to stall.

When it does stall its quick, most of the time, its like ive turned the key to off. Doesnt seem to make a difference whether ive got constant throttle, whether im pulsing it, or letting it idle. Runs smooth until it dies.

Sometimes it will bog down a few hundred rpms and come back. Once it bogged down to 2-400 rpms, then stalled, and while it was bogging the ce and tracoff lit up. but mostly just died without warning on maybe 10-15 starts. No difference when hot, if anything it took longer to die.

Going to try to get it the 3miles home tonight like this, then pull codes. Didnt have anything with me to jump the te1 and e1 ports. Next guess, tps.

Sigh.

PureDrifter

iTrader: (10)

stop throwing parts at it and diagnose it properly..

Chilkoot

Yeah, tomorrow when it's home I intend to do just that.

In my defense, i already had the fuel filter. Id been dreading it and procrastinating, so had it sitting in the trunk.

fsuguy

Test the other coil - it should be less than .6ohms. Also, test the fuel pump resistor. Both of these tests should be done across the heat range, since at different temps the specs should match OE. Also, there are Vacuum Switching Valves (VSVs) that go bad - not sure about the '93, but think the '92 has three of them. Another thing to test is your EGR temperature sensor. All of these may work when cold, but go south when operating temperatures are reached. Finally, use a pressure gauge plugged into the fuel rail to check actual fuel pressure and the pressure regulator. Not sure about the '93, but I believe you should have at least 44 psi.
HTH