No-Start Condition (Fuel and Spark, but no Joy)

[NeedPrscheSpeed]

Greetings to all.

The car in question is a 1993 968, and the no-start problem arose about two weeks ago in 30 degree weather. Earlier that day, I remember thinking, "Well, is she going to start." She did that time, but later on she did not. (I'm quite the prophet, it seems...)

Okay, without further ado, so far, I have done the following:

a) Changed out the DME Relay (with the 1992's)
b) Checked the Fuel Pump Fuse
c) Inspected everything under the hood
d) Held the throttle open while cranking the engine
e) Changed out the distributor rotor (with the 1992's)
f) Changed out the distributor cap (with the 1992's)
g) Tested for Spark (spark at all four plugs)
h) Checked the fuel pressure (it seems just fine--it registered 60 psi)
i) Redundantly changed out the coil, just in case (with the 1992's)
j) Noticed that tach bounce is present (So, the reference sensor should be fine)
k) Rolled the car off a ravine (J/K) (Hey, a joke won't hurt when a man's down...)

As you can infer, as with any problem in which spark and fuel are present, this problem does not lend itself to an easy diagnosis. I have a few ideas:

a) DME computer

Even though I have fuel and spark, perhaps something has gone awry with the computer. I seriously doubt it, however, for it makes perfect sense to me that if spark and fuel are present, combusion should take place. I should add that the does attempt to start intermittently; on some days it has shown slight signs of life, but generally for only short bursts. On other days, no signs of combustive activity has been present. When the 1992 went down in 2005, the problem ended up being the DME computer; however, a tell-tale sign was present: there was no spark.

b) She has skipped time

I spoke with my mechanic earlier today, and he said that there is a chance that the belt slipped on the car and that she skipped time. (If the car has skipped time, here's to hoping that the valves survived!) This is certainly a possibility, for why else would both spark and fuel be present without any combustion? When I checked the belt at the camshaft pulley, sure enough, it did seem quite loose... What's worse, oil was on the belt! Darn it! Back in November, I inspected the belt, and all seemed well! At this point, even if the car is not mistimed, I would be a fool not to have the belts done; while I'm at it, I'll throw on a water pump, too, of course.

c) Starter

The starter seems to be spinning the engine quite slowly, even with a new or freshly charged battery. It seems unlikely that it would inhibit the car from starting, however, for when the temperature is in the teens or single digits, the engine turns over very slowly, yet still fires up.

It is glaringly obvious that the next thing to do is to get the engine set to TDC and see if all is timed properly. (I will have to do that tomorrow, for I have absolutely no energy left after having worked for 16 hours per day the past three days!) Apart from that, I suppose that I could switch out the DME from the 1992 model.

If any of you can provide any insights, I would greatly appreciate your doing so.

Thanks for reading!

[dapatch]

Hello NeedPrscheSpeed,

Any progress yet? My '93 968 suffers from the exact same problems.

Patrick