Speed/Reference sensor test

[mikseymono]

Thanks George...sadly mine does not have the in built space for the bracket.

Just asking if the 0.3mm spacer is critical to it sitting square to the teeth of the flywheel?

Thanks,

M

[Jfrahm]

There are cheap DMMs these days for $20 and less that will measure Hz and AC voltage from sensors like these. Maybe the ZT102 for $16 'merican, that looks like a good choice.

I'm thinking it's a spark problem in your case but you might be able to inductively measure that while driving. Or maybe first try to observe the DC pulse frequency at the coil while revving/driving.

-Joel.

[mikseymono]

Have just found out the speed sensor female plug is intermittent. This is the plug that goes back to the DME (ECU) It is the wires just behind the plug....certain bending produces no tach bounce/start and another way starts straight away......probably my fault as I have pulled these apart 20 times or more in setting various sensor gap combos....

So, finally, a problem that I can solve....HOORAY. :clap:

So, what are the options please to repair this lead.....not much room or length in the lead to splice much.

Would this have an impact on my rev issue or am I being over optimistic?! :food:

M

[944 Ecology]

https://www.lindseyracing.com/LR/Porsche/LR-944-HAR-REF.html

[curtisr]

The part number for the figure 8 washer (should you not know) is 951 101 325 00. You can get them here and here among others.

And I'm sure you've heard this before: avoid the FAE sensors (should you need them). I tried them without success and had to borrow some Bosch ones from a friend. Bingo! Car started.

[mikseymono]

So...my "B" reference sensor is definitley intermittent. I need to unclip it/bend wires to get it started/tach bounce every now and then. I feel that I will change the sensor first, as I have a spare, before I try and splice in new cable.

The question is though, once started I then pulled the B reference sensors apart and the car still ran....is this normal?

Thanks,

M

[mikseymono]

Ok...so its been a few days since my last post.....

I have managed to get the instrument panel battery light up and working now and this has definately made things better. It can now pull towards 5000 rpm There was no earth strap on my alternator just the exciter small blue wire and the heavier gauge one to the starter. Would this make a massive difference?

However, it is still pretty pedestrian......I have checked and changed the reference sensor twice now...but as I have nothing to compare it to I don't know if this is good or not. It all checks out as per Clarks....but it is definately not right.

For the moment the car runs and gets to speed eventually which around these parts is generally an earth shattering 80kph......

I fear I may have to visit a local Porsche mechanic as I seem to have exhausted all sensible possibilities....but open to other suggestions.....

Thanks,

[944 Ecology]

Originally Posted by mikseymono

The question is though, once started I then pulled the B reference sensors apart and the car still ran....is this normal?

Thanks,

M

Yes, once the ECU has figured out where TDC is, it simply counts the teeth on the starter ring gear to know where it is from then on. Of course, you still need both sensors to get the car started.

[mikseymono]

Ok...so here it is.....my 0-60mph time.......don't always rag it but this was basically WOT from standstill up to 60 mph....about 11 seconds!!...3rd gear pulls quite well but first and second seem really strained. It is certainly alot better since I put in the battery dash bulb and can rev it up to around 5300rpm.....but no red line...and I tried......still very slow...according to by power curve diagram 60 mph should be achieved by just going into third.

https://youtu.be/uDEjcsI3nSs

So...all comments welcome!

Thanks,

Michael

[DannoXYZ]

Originally Posted by mikseymono

So...my "B" reference sensor is definitley intermittent. I need to unclip it/bend wires to get it started/tach bounce every now and then. I feel that I will change the sensor first, as I have a spare, before I try and splice in new cable.

No need to splice in cable. Just snip off the connector and install new one. I listed all parts needed to replace just about every connector in harness here: DIY Harness Connectors