I'd rather see the definitive "swap ecu controlled alternator to reliable NA setup" thread.

 

I've fried two cam sensors in 3 days. I wired it such that the cam and crank sensors share the +12v & gnd that used to power the cas. I wired the cam sensor pigtail as pictured below. Is this all correct?

Full disclosure, both of the cam sensors were used. "Stop being a cheap bastard & buy a new sensor" is a perfectly acceptable answer. I just want to get confirmation that my wiring is legit.

 

That looks correct
What do you mean "fried"

 

Thanks

By fried, I mean stops working. Both created signal in composite logger and ran the car fine for about a day, then car won't cold start. No signal in composite logger. I swapped out the first dead one, and car fired right up. Now the second one isn't sending signal. If the wiring looks right, I'll pick up a couple new sensors. Could be I just had bad luck with used sensors.

 

Thats odd. Are they fried forever? Like if you use the first one again is it still dead.

 

Haven't tried. I'd be tempted to test that if it was a hot start issue, but cold start? Seems unlikely. I can plug it back in & see what happens. What's your theory?

Don't want to cause too much thread drift here. I'll buy some sensors. Thanks for validating my wiring.

 

I think Sav has said that he's had the experience of buying a new cam sensor and it being DOA out of the box. Keep a spare or two around (and test them, of course).

 

No theory. Just want a complete picture. Too many times have I assumed something was broken, or not broken, only to test it again and find out I was wrong.

 

I had the same CAS on Rover for a couple of years, and it finally started acting up in hot weather in March, then died completely a week later in cooler weather. I swapped in another one, which lasted a week until it, too, died in hot weather. The third replacement has been solid. The OEM CAS design is garbage, I would always carry a spare in the glovebox and 2-3 spares if you track the car.

 

I havent had one fail completely. But the only ones I've had luck with are the old OEM ones that dont have the diamondstar mark on it.

 

Hello everyone... I have been working on this swap since last September and finally got some time and motivation to try and figure out why I can not get this VVT swap to run.

I am confident I have double/triple checked my wiring based on the "Definitive" write up... I had spark, fuel, and compression last I checked but I can not get the car "RPM SYNCED" with the MS3 basic...

The current setup is 01 VVT long block, Squaretop intake manifold, Skunk2 throttle body, Jackson racing header, racing beat full exhaust and aftermarket cat. I am using the 94-95 MS3 Basic for my ECU. Transmission is an 04 MSM 6-speed, Toda 1.6 flywheel and 1.6 ACT clutch... currently have the Torsen I 4.1 diff...

In my search for any possible reason why I can not get this motor running I came across a question in reference to the 95.5 Miata and the MS3 Basic. My manufacture date on my Miata shows 03/95. My factory ECU is a "BPL9B" which I searched today and it came up as a 95.5 manual ecu... I purchased my MS3 basic as a 94-95 and I am wondering if I should have purchased the 96-97?? I am no expert by any means and this project has been a learn as I go project but I am so bummed I have everything installed and the car still doesn't run...

I had a spare 94 harness from a 94 manual... The ECU is a "BPE8" and I noticed the ecu harness is missing one blk/wht wire compared to my 95.5 ecu harness...



In short... is it possible my Not RPM Synced could have anything to do with this blk/wht tach wire?? Or does the 95.5 Miata require the 96-97 MS3 Basic... Any suggestions or direction would be a big help.

 

A couple more pictures to go with the last post...

 

That blk/wt wire is simply the ECU's tach signal. Provided by the coils in the earlier NA8s, so it doesn't go to the ECU.

Check for spark and fuel for both coils and all four injectors in test mode, report back.

composite log too please.

 

Thanks for the quick reply. Just confirming I do this in the "Output Test Mode Inj/Spk" ?

 

Yes. You'll have to fiddle with the settings but you'll hear a clicking sound, unplug coils and injectors to make sure each one is working if necessary. You can also test your tach, VVT, IAC, and fan in the output test screen.

 

I went through the Output Test Mode Inj/Spk test...

I can hear my fuel pump priming when I turn the pump on.

I can hear a faint clicking with the coils (A-B) This was a bit more settle than the injector test.

I can hear the clicking of each injector (Injector A-D). (My injectors (01+ purple injectors) were tested and gone through before this swap.)

I am not sure how to provide you the best composite log so I took a picture by phone. Looks like a sync error... I did replace the cam and crank sensors with new sensors and have checked the tooth gap with a "credit card"..

Again I am figuring this out as I go so if I am doing something completely wrong I am all ears to get on the right track!

 

No sync error there. The ones at the beginning are normal as it starts up. So it looks like its syncing. Are you getting spark?

 

What settings are you using for the ignition pick-up, '99+ Miata, rising edge, falling edge etc.?

 

Post tune and log

 

I use an mspnp pro for my vvt swap in my 91. After getting the car running I noticed that there was no tach. So after reading what might solve this. I installed the tach out jumper. But now the car won't start anymore and there is no crank and cam signal in the composite logger. All fuses are fine and F1 and F2 are still getting the required voltages. Also both sensors recieve 12 volts on the pigtails.
Any advice on how to get these signals back ?

Thanks in advance,
Cedric