Fitted 36-1 trigger wheel, firing on 2 cylinders
 

Hi,

I have a 1996 1.6 miata running on DIYPNP. I decided to upgrade from the CAS and fit a 36-1 trigger wheel, whilst still using the cam signal form the CAS for sequential fuel. The CAS was modded by removing all but the smallest cam signal tooth.

The car now starts and runs but only on cylinders 1+4, I adjusted the #1 tooth angle so the spark angle matches my timing light but it's still the same. I have a feeling it's something to do with this number or some sequential injection settings that need changing.

I've attached my tune and a composite log.

Attachment 56367

Attachment 56368

And here's a screenshot of my composite log

https://www.miataturbo.net/attachmen...ine=1349122878

Thanks in advance for any help.

Nile

in ignition settings you have "single coil" - that needs to be wasted spark.
also your trigger wheel is on backwards if your angle is 246 degrees.... should be like 80-85.
finally I would change 'second trigger active on' to Rising edge instead of falling edge.

Ah! Can't believe I missed that. It's too late here to test now but i'm sure having single coil selected is the problem.

The tooth angle I got from this guide, plus some adjustment with the timing gun.
MS2-Extra Dual Wheel Manual

Thanks for your help.

Single coil is your problem.

I'm just saying you put the timing gear on backwards - outer side needs to be facing.. out.

If it's triggering reliably, it doesn't matter.

Thanks for the help.

She now runs on all 4 cylinders, but badly. I keep getting sync losses, especially during cranking. I made sure the cam signal is not too close to the missing tooth signal so i'm not really sure why.

Here is a composite log of cranking.
Attachment 56476

Soviet, the timing wheel i'm using is a universal ring gear welded to the bottom pulley, I fitted the wheel in the Ford edis style, so tooth 9 lines up with the tdc mark at tdc.

The composite log looks perfectly fine.

post a screen capture of when you lose sync.

Ok I can't even get the car to start, so both of these shots are from cranking.

Attachment 56485

Attachment 56486

I see I get error 1 and 2 for sync loss. What does error 1 init error mean?

Thanks

doesnt appear to be really capturing your cam signal anymore, as well as skipping teeth on the crank.

This is the latest comp log, it does have a regular cam posn signal.

Attachment 56495

I just want to confirm that the cam posn signal is supposed to be read before the missing tooth? Also that the polarity of the signals is correct?

cam needs to read anywhere but at the same time as the missing tooth, looks like you're okay juding by the above.

you have cam reading as rising and crnak as falling?

If he's using the protege 36-1 wheel, it's concave on one side, like Miata wheels. it should be mounted the right way because otherwise it pushes against the crank pulley.

OP you need to play with your VR pots.

Both are set to falling at the moment. I will try cam rising.

Does the DIYPNP have VR pots?

It should.
I just installed the same trigger wheel and had to play with pots to get it working. It still works but I have a lot of trigger error now, so I guess I need to fine-tune it.

Also, disable cam signal altogether now and just get the trigger wheel working. Switch to batch fuel and get the RPM signal nice.
And yes, cam tooth comes before missing trigger wheel tooth.

Still no start with the second trigger set to rising.

The weird thing is the car did start earlier and was idling ok.

depends on how you built it. You can add one and change the threshold of VR2 only.

Your previously posted composite logs looked great, but these look horrible. What has changed? Do you have a bad wire connection? Is your crank sensor not solidly mounted?

Exactly what sensors are you using? Is the CKP a VR type?
I'm assuming that CMP is hall or opto, modified from a CAS?

I think he's using the stock 96 crank sensor which is VR.
On related note, would there be anything to gain by switching to 99-05 crank sensor? It's a hall and has same mounting and connector. Wiring would be trivial - just switch one wire from ground to 12V.