dualblade

ok, so i finished my insanely long clutch job and am ready to go, but the car seems to not be. when i first finished, i turned the key and the car actually did start up but it was late and i hadn't put the exhaust on yet so i killed it. the next day, i started it up again and gave the gas a bit of a kick which made it stall. i tried to fire it up again and it didn't seem to idle well so i gave it a little bit of gas. when i did, i heard a metal on metal sound (never good) and the car stalled. took a look at my reference sensor and there was scoring on it so i hadn't aligned the bracket right. got a new reference sensor and made sure to align the bracket right this time (last time i just sort of guessed at it but this time was more precise), but the car won't fire. i took a look at the plugs and there is fuel on them from cranking so i'm guessing that's not the problem. all 4 of them had fuel on them so i'm covered in all 4 cylinders. now i'd like to check for spark and i'm curious how to do this. if i don't have spark, what are some causes. i don't think anything happened to the dme when it was in the garage (at least, i can't imagine what could happen), but the afm did come out to be taken apart and adjusted. i don't think anything else happened that might screw things up but you never know so please suggest any likely causes. since the reference sensor was disconnected, is there any possiblity the car is not timed right?

your help is much appreciated, as i haven't driven the car since august and i'm really excited to

Luis de Prat

I just had the clutch done on the 83 (not as brave yet as you are) and I had the chance to check in on the shop that did the work. There is a tiny bolt on the flywheel that's supposed to barely touch the crank sensor.

Did you have the flywheel resurfaced, and if so, is it possible that this little bolt was hit in some way? Hopefully, the sensor itself can be adjusted like you're implying, in lieu of pulling the flywheel out again.

dualblade

thanks for the suggestion but s and s2 cars don't have that bolt. the na and turbo cars have 3 sensors on a bracket over the bellhousing but the s and s2 cars only have one - they use teeth on the flywheel so that one sensor can gather all the data it needs. na and turbo cars have smooth flywheels with that one bolt that one of the sensors reads.



actually this brings up a question. is the process to align the reference sensor different for the s2 than the regular na cars? i took my old reference sensor and glued on a .8mm thick washer as in clark's garage's procedure. this was for alignment so that when the new sensor goes it, it would be .8mm above the flywheel. is this not the spec for s/s2?

Dave951M

Have you checked to see if the sensor is fully plugged in? My connector was cracked and could be wiggled enough to stop the car from running, but still look like it was making contact.

dualblade

it seems like it's in there pretty good and since it's a brand new sensor, i'd assume it's in good shape. or were you talking about the connector on the car side?

really i'd like to first test if the car is getting spark and then go from there. how can i do this? i've heard of some trick with grouding a screwdriver but i don't know the details.

SidViscous

Hey Luis how much did the Clutch job cost you, looking at it soon myself.

RajDatta

Andrew, in order for you to get spark, the speed/reference sensor has to work. That is how the dme knows when to send pulse to the coil to fire spark to the designated cylinders.
I have a feeling it is something related to your speed/reference sensor. You are correct that there is no magnetic trigger on the 16 valve cars, just a set of teeths (60-62) with a section where 2 teeth are missing. This is where the reference takes place. Everytime each flywheel tooth passes the sensor, it creates a sin wave and when it sees a flat area, it knows its the missing 2 teeth and hence it references the TDC mark or 8 degress before it (if I remember correctly).
Please tell us exactly what was changed? was the flywheel re-surfased?
If you are not getting spark, you are not getting signal from the sensor. Next, I would check to see if the sensor reads when you crank. I think its the 2 outside pins that need to be connected to an oscilloscope(sp).
Raj

MHT

pull one of the spark plug connectors out, stick a screwdriver in the end of the connector and hold it so the shaft of the screwdriver is about 1/4 in. away from something metal, crank the engine and you should see a spark between the shaft of the driver and the engine. Hold the screwdriver by the handle, not by the shaft and try not to be leaning on the car while you test it. 40,000 volts through the end of your "equipment" does not feel good.

Dave951M

I was refering to the connector that connects the sensor to the wiring harness. That's where mine had a problem. Looked connected but wasn't fully. Sometimes it would run and other times not start at all.

dualblade

sorry for not being specific enough. flywheel was lightened (slightly) and resurfaced. lightening didn't effect any of the teeth on the trigger wheel and didn't even come that close to them so i don't see that being a big problem (but i could be wrong of course). then i took it to have it balanced and resurfaced cause that's what i was told to do after the lightening procedure.

SoCal Driver

Signal comes in on the DME connector pins 47 and 48.

The adjustment for the sensor is the same at 0.8 mm.

This is a diagram of the signal. Detail 1 is the speed. Detail 2 is the reference.

Luis de Prat

Not to hijack the thread, but I guess the bump is good anyway!
Sid, I got a great price on a SACHS spring-centered clutch from Zim's Autotechnik, which I believe is a Rennlist sponsor. $439 for the kit including the disc, pressure plate and throw out bearing.

Additional items I needed were a pilot bearing, flywheel bolts, flywheel main seal, and clutch bolts. I also had to get a used and resurfaced flywheel which I bought from Ian's Euro, since this is the 4th clutch on the car and the original flywheel had been resurfaced a few times already.

Labor here in the Caribbean was $375 for the job, significantly less expensive than what I usually see quoted in these forums, which is why I didn't bother attempting it myself.

SidViscous

Expect more here. But not near as bad as I hoped.

Don't know how many mines had, but I assume my flywheel needs to be re-surfaced as well.

dualblade

is there any way to check output other than using a scope? i'll get one if i need to but right now all i have is an average multimeter

Big E

Without building a circuit to convert frequency to voltage (or having test equipment that already does this), you need a scope to actually look at the signal. Signal also must have a minimum peak-to-peak voltage, 3V as I recall, otherwise car will start/run/die sporadically (speaking from experience).

Make sure you're looking at the right connector, there's a second test connector located next to the real one that that isn't normally hooked up but let's you look at the timing signal w/ the engine running.