Perry 951

It looks that way. Under the speed sensor, there should be a spacer. It has a hole for the sensor, and one for the bolt. If that is not on there.. it will sit too low. Because of the way the arm works, this actually raises the height of the reference sensor.

You need to get that spacer, then gap the sensor to .8mm. That could be the reason the DME senses cranking, but won't send spark. It may not be getting the reference signal.. therefor it has no idea where the motor is sitting timing wise.

GOBOGIE

Too funny Danno, I needed a good laugh today (me and the Mis's had a tiff).

Hang in there bud!

Dan87951

Cory this car has brought to much negativity, it was time to have a good laugh.

Chris_924s

Cory- you didnt borrow the laundry bucket without asking again? Didya??

I touched up the pic to give it the proper "feel" Hope you get a laugh Dan!

I can almost smell the bad vibes coming off that guy!! j/k Dan.

Dan87951

LOL, Yea you sure could smell the vibes that day Chris, probably even see them!

Danno

Sorry had the URL mistyped:


Minimum positive peak on the Ref. signal is 2.0v and the amplitude of the Speed signal should be 2.5v or greater.

Perry951 is right on about that spacer; it allows you to adljust the two sensors relative to each other since the bracket wil adjust both of them simultaneously. Another stupid engineering 'feature' by Hans & Frans for ya, they could have built that bracket so that both sensors are in the correct position when they're fully inserted.

Anyway, I suspect that your Ref. sensor is too far away from the trigger on the flywheel. I've seen people unscrew the allen-key screw on the flywheel to make up for this, but I don't know how many threads you have left in yours. Also they tend to be loctited pretty well to the flywheel and trying to unscrew them often breaks it.

Martin

Grab a red LED and connect it across pins one and two of the crank sensor plugs, get an assistant to crank the engine, the spped sensor should flicker constantly and the ref about twice per rev.
You can inspect the pins through the starter hole.

Tom Carson

I like the idea of being able to just use an LED to see an output from the flywheel sensors

I don't see the speed sensor's 'D' spacer here either...which models must have them?

http://www.pelicanparts.com/944/944_...-85/Pic109.jpg

Danno

"I don't see the speed sensor's 'D' spacer here either...which models must have them? "

In that picture, it would be right next to the number "13" pointing to the washer. You'll notice on this bracket that both mounting points for the speed & ref sensors look exactly the same? Yet the picture posted on the last page from Clark's Garage shows more emptyness under the speed-sensor? The D-shaped water gives a lip to the mounting surface and provides a hole for the bolt to go through like on the reference sensor.

89magic98

My microfiche shows the washer... part 951.101.325.00... see #29 in the picture (this for 86-88 924s).

Dan87951

What is wire 24 at the very bottom of that picture do? It looks like another sensor or something. I don't have that could that be a problem?

Perry 951

That is the TDC / external tach sensor. It is for diagnostics only.. you can run without.

Tom Carson

Kevin...the diagram also shows a 'sleeve' for the reference sensor (part 28) while the 'early' .jpg shortcut I posted has none

so I guess my real question should be which brackets must have these 'D' spacers since so many brackets might/do get replaced with a different p/n

just the ones with a sleeve?

(not to mention that little 'tension sleeve' part 21 that reduces the mounting bolt hole size...I'll bet many are replaced without that part too)

89magic98

Tom,

I'm 100% sure that my diagram is correct for '86-'88 924s. This is a scan of the factory microfiche. This would leave me to believe that it _should_ be correct for Dan's '87 951, since I can't imagine how this part would be different for turbo/non-turbo cars. He should take a good look at his other '87 951 and do a comparison.

On possibility is that your diagram might be a 3rd party copy of the drawing, and might not show 100% of the parts.

I know that on my car, the D-ring and the sleeve make "almost" an air-tight fit when the sensors are put in and removed. I wonder if the sleeve would also effectively raise the sensor a bit. I also wonder if that sleve somehow provides magnetic shielding for the sensor.

I think we're on to something here. Maybe someone has a PET diagram of this that they can post, so we could be 100% sure.

The other point I was thinking of was that if Dan has access to an oscilloscope, he should use that to make the measurement. Since he has brand-new speed/reference sensors, the _quality_ of the signal is what he should be testing for, not that he has some kind of pulse as seen on a led.

-Kevin

Dan87951

What parts do I exactly need? It looks like you guys are telling me I need part 28 and 29 from that diagram. If anyone knows the exact part numbers I would appreciate it if you posted them on here so I can get these parts ordered ASAP.

part 951.101.325.00

The above is one of the parts I need correct?