car runs for 2-3 minutes then dies.

[aharris82]

I would love some help solving this problem!

My car will start from cold and run for about 2-3 minutes, then cut out and not be able to restart. It will then turn over but not start. It'll then start from cold the next day and do the same thing.

Since I have spark, does this rule out all ignition related issues?

*After it dies, when you try to turn it over, I've confirmed i have spark to all 6 spark plugs.
*Reads 0.2 Ohms across the coil
*Reads 5.0V across the coil
*I tempsticked the water pump externally, and it cut out when the outside of the water pump hit just shy of 110F.
*I tried to measure fuel pressure between the control pressure regulator and the fuel distributor but I don't have the right fittings to get my gauge connected inline.
*I tried unplugging the oxygen sensor, which made no difference.
*Fuse slot 7 looks melted out, and the car operates no differently with a fuse in it or not. Slot 7 is Lambda, frequency valve, fuel pump, and control pressure regulator. I don't believe this is the problem, because it has been like this the whole time I've been driving the car for a year. Perhaps it is just jumped underneath?

Prior to this issue starting, the car was running fine.

[Bitsyncmaster]

The cold engine start will drive the frequency valve at 50% duty. After 2 to 3 minuets the O2 sensor is hot an drives the lambda to closed loop so the FV duty will change. With that info, it sounds like your mixture adjustment must be way off. You would need to try to do a base line adjustment since it won't run closed loop to adjust it via dwell meter.

[Michael]

I think Dave is on the money but if it was running fine one day and all of a sudden it's exhibiting this issue, something happened. Mixture doesn't get that out of whack without something big and probably obvious happening. Look for big vacuum leaks, unplugged or broke wiring especially around the CPR, frequency valve, microswitch area, etc.

Maybe even start with the basics like checking fuses and the battery voltage (also check voltage at the pump while it's running till it dies) so you don't spend an afternoon diagnosing in circles.

[Ron]

Sounds like you have spark.
For fuel, next time it dies give it a shot of starting fluid and see if it fires off. If so, check the filter (and as mentioned, that the pump is still working).

Does it just up and die, start missing first, smell rich, or...??

[aharris82]

Sounds like you have spark.
For fuel, next time it dies give it a shot of starting fluid and see if it fires off. If so, check the filter (and as mentioned, that the pump is still working).

Does it just up and die, start missing first, smell rich, or...??

It outright dies instantly after that 2-3 minutes. Until then, it runs as good as it has the whole time I've had it. It sounds/smells the same as it has. I'm not seeing how that could be related to the fuel mixture?

I bought the car at DMC-MW last year and had them do the Stage II upgrade before delivery, so its mixture was just dialed in a year ago. I'll look again for leaks, and try the starter fluid test.

[aharris82]

Also for what it's worth, the cold start valve has been unplugged since I got the car. DMC-MW unplugged when I first bought it last year, after the stage II conversion. The cold start valve was causing cold start problems back then, and it started fine with it unplugged.

[Michael]

*Fuse slot 7 looks melted out

[David T]

You have several issues to deal with. Make sure the frequency valve is buzzing when it is running. Get the cold start system working again. Fix the melted out fuse #7. Check for spark the next time it dies. Could be a bad impulse coil but they usually shut the car down after 15-20 minutes, not 2-3.

[Helirich]

Well, the equation is spark + compression + fuel. The compression isn't going away, so it must be fuel or spark. Spark is probably the easiest to check. (It's also the most likely to quit fast)

Please let us know what it is.

[Ron]

He said it had spark...