Engine cuts out while driving......then starts back up by its self

[CJG]

.

[khalild]

A tune-up is in order. At the least it's a bad filter.

[Sagaris]

I would say the main ECU relay is bad.

[wodcutr]

If your car's starter engages by itself then you have major issues! If your car loses power while driveing then it is most likely the ECU, main relay, fuel pump relay, fuel pump, ignition switch, or a short in any of those wires that control these things! Get a bentley manual and start to diagnose.

[smcdermott326]

in my experience, this usually means you should replace the main and fuel relays. While idling you can open the hood and smack them with a screwdriver handle to see if you can get the car to stumble. But replacing them anyway is an insurance policy on a 20 year old car.

Either way you'll still have electricals working while the car is traveling at road speed. And if you are still in gear when the problem goes away (relay reconnects) you are going to be pop starting your car as you go down the road.

Where in CT are you?

[asubimmer]

could be the vacuum hoses too...

[StereoInstaller1]

Main relay without a doubt.

The tach dropping to zero is the big clue.

[jlevie]

The starter doesn't engage but the engine starts back up. Its really weird I can hear the engine stop and the rpms drop to 0 and I can't accelerate and if I just coast for a few seconds it just starts back up and then I can drive like nothing happened. I was thinking that it was probably something with the ECU. I'll try replacing the relays like you guys said and see if that helps.

Does the CEL come on while the engine is "off". If so I'd suspect the main relay, fusible link, or DME. If not I'd suspect the crank position sensor.

[FredK]

A tune-up is in order. At the least it's a bad filter.

The car is already tuned up, as I used to own this car. It has new plugs, fuel filter, distributor cap and rotor.

I think I have a pair of new relays somewhere, let me check.

[StereoInstaller1]

Remember that the "Main" relay is different than any other relay on the car

[jlevie]

I didn't notice if the CEL came on but I don't know for sure.

That is an important clue. If the DME looses power while the ignition is on the CEL will illuminate while the engine is "off" and will extinguish as soon as the DME turns back on. Loss of power to the DME and loss of timing reference data are the only two things that will cause a "shut off" of the engine and the tach going to zero will the car is in gear and moving.

The CEL comes on before the engine "shuts off" the odds are that the crank position sensor is to blame.

[StereoInstaller1]

and if the gauges crap out (not just tach, but all of them) while you are still moving it is DEFINITELY main relay

[StereoInstaller1]

Hmmmm...lemme go look at the diagram

[jlevie]

and if the gauges crap out (not just tach, but all of them) while you are still moving it is DEFINITELY main relay

The main relay has nothing to do with any of the gages other than the tach & econometer. And those only because they are driven by signals from the DME.

[FredK]

This really has me scratching my head! I'd see a long crank every now and then during my ownership, but it was always fine during operation. Does the shutting off coincide with hitting a bump or anything like that?

Maybe something is interrupting the DME power, like the fusible link is going bad or something?