928 died

cas928s2 · 12-01-2008, 06:01 PM

85 928s2 euro died in road. have spark, fuel pressure, noid light firing, computer fine. please help! cas.

Danglerb · 12-01-2008, 06:07 PM

Spark, fuel, and compression.

Did the timing belt break or slip?

If it seems ok, then try a compression check. If the compression is ok, recheck spark and fuel.

cas928s2 · 12-01-2008, 06:15 PM

belt good+tight. if i lost the belt i wouldn't have a spark. one thing i noticed, no wet plugs but i smell fuel from the t-body, not the exhaust

Danglerb · 12-01-2008, 06:23 PM

Have you checked the spark on more than one cylinder with a timing light? (dual distributor belt can break).

Does the car still crank fine?

Too much fuel also can occur, but I would expect a few wet plugs. In fact if it isn't firing plugs should be wet.

Sure you aren't out of gas or fuel filter is clogged (I know you said you have fuel pressure, just double checking).

Do you smell gas on the vacuum side of the fuel regulator?

cas928s2 · 12-01-2008, 06:53 PM

spark from both caps, just fueled, no fuel from either p-regulator or dampr. press. at 38-40 psi and holdes for 15+mins. when chkng injectors with noid lights does noid flickler continuesly or blink every firing cycle.

Danglerb · 12-01-2008, 08:57 PM

Flicker does not sound good. I was using a noid light a couple weeks ago, but I can't say for sure exactly what it did other than go on and off. Injectors all fire at the same time, ONCE per cycle (2 revolutions per cycle), so with a 600 rpm cranking speed, thats about 5 blinks per second.

If you use a length of rubber tube held to your ear and next to the injector you should also be able to hear it click.

*************** Check your XXV relay

Dean_Fuller · 12-02-2008, 07:17 AM

Quote:

Originally Posted by cas 928s2

85 928s2 euro died in road. have spark, fuel pressure, noid light firing, computer fine. please help! cas.

How did it die??? Just shut off??? Odd noises before? Dash readings before? Any hard starts before? Motor sounded fine up until???

cas928s2 · 12-02-2008, 04:53 PM

hi dean. yeah, just died like no spark or no fuel, drove 1 block and it just died out on me. i was thinking crank position sensor but i don't know if that controls fuel or spark. it seems to me like no fuel or a weak spark. cas

Danglerb · 12-02-2008, 06:16 PM

Quote:

Originally Posted by cas928s2

hi dean. yeah, just died like no spark or no fuel, drove 1 block and it just died out on me. i was thinking crank position sensor but i don't know if that controls fuel or spark. it seems to me like no fuel or a weak spark. cas

You wouldn't get spark or fuel, I forget which or both.

Weak spark, I don't think so. Spark enough to flash is going to ignite at least some of the time.

This feels like something basic is wrong.

How was the spark tested?
Most reliable is to pull a plug and put it on the block to ground and watch while the engine cranks.

Noid tests the voltage signal to the injector, but with a plug out if you get no gas smell the injector isn't spraying anything.

Really verify spark and fuel, then do a compression check.

cas928s2 · 12-03-2008, 05:03 PM

hi danglerb. i have to check my timing belt, feels like somethings wrong. i lined up TDC on my damper. and saw my cam gears where off by 12 teeth. even if i have to rebuild, i will! refuse to take a euro off the street. next,compression chk and i'll keep you guys posted. a word of advice, don't buy an aftermarket timing belt. only from worldpac or porsche. the teeth on mine are starting to shear after only 30k miles.

MPDano · MPDano's Garage

I use a Continental brand which I've never heard of premature failure, but I guess it could happen with any belt. Sounds like your on your way.

Danglerb · 12-03-2008, 07:42 PM

***No point in a compression test with the belt wrong. Pull the covers, see whats wrong, and fix it before turning the motor. Piston to valve contact seems kind of likely, but the bottom end may be fine. I agree even if it needs a rebuild a Euro S is worth it.

I can't believe a 30k belt would have teeth issues without some major other problem regardless of brand unless its also really old. None of the belts are "bad", but some may be a bit better than others.

What shape are the timing gears in?

The cam gears should have no aluminum visible under the protective coating.

Are all the gears and belt the same type, round or square tooth?

I wanted a Gates belt last time, and due to a bit of confusion ended up with a Flenor (something like that) from WorldPac, but its supposed to be very good.

Continental some people think stretches, but I've also heard its the OEM belt to Porsche.