Hi all,

I've just started my turbo project, and the first thing I've done is the MSPNP. I installed it with pretty much default everything and with the base map. It runs and drives fine. Megatune shows RPM, but my tach no longer works.

I didn't do any firmware updates so I don't think I fried the ignitors, also when I plug the stock ecu back in, the tach comes to life again.

At this point my car is all stock, except I did install an alarm with a remote starter several months ago. The alarm has a tach sense wire so I'm wondering if this is somehow screwing up the MSPNP. Alarm used to work fine, but now the remote start won't work since there's no tach signal.

Can anybody help me figure out what's gone wrong?

The car is a '95M. Alarm is a Hornet 564t.

Stuff on the garage floor waiting to be installed: BEGi S3, COPs, ACT Streetlite, Exedy Stage 1. Stuff on the way: Metal Cat, Enthuza 3"

 

Do you have a 95.5?
Do you have a wire on 1F or 2I?

 

As far as I know it's a 95. No OBDII.

Tach sense is on 2i

 

Unplug the wire for the alarm going to the tach wire to see if that is the problem. You are your own best troubleshooter.

 

It'll probably come to that.

I'm hoping to avoid messing with the alarm as it is *well* hidden

 

Did you remember to take out the 10amp fuse?

 

seriously, why do you try?

 

both the 95 and 95.5 will not be OBDII but the 95.5 was prepped for OBDII. IIRC, the pnp works great in my 95, but in my friend eric's 95.5 it worked except for the tach. my guess is that u have a 95.5. whats the code on the stock ECU? how many wires are going to the coil packs?

 

Eh you never know.

 

Not necessary on the 94-95

The code on the ECU is 079700-6022. I'll check the # of wires when I get home.

What did Eric do on his 95.5?

If it turns out that I do have a 95.5, I might try making my own tach driver as found here:
and here

If I make this tach driver, can I backfeed the signal into the tach wire, or will I mess up the MS by doing this?
Now that I've put more thought into this, my tach sense may not be wired into 2i.
I just wired it into the correct colored wire under the dash and I assumed it was 2i because thats what the wiring diagram shows.

 

Talk to Jerry so you don't **** your MSPNP up doing this, but when we installed orion's MM9697 Beta, Jerry had loaded the MM9495 basemap onto it and we forgot to reflash to the 96/97 basemap (or firmware, forgot which). His tach didn't work until we reflashed. (probably firmware)

 

Is it on 1F or 2I. Just go look already.
If it's on 1F then report back here and call Jerry. If that is the issue then you should be able to take a 1k ohm resistor and jumper the 12v and 1F wire to get your Tach back.

TALK TO DIYAUTOTUNE before doing anything, just like Savington said. I don't really understand why people come to the forum first before consulting the company who they bought their product from. Jerry/Matt answer emails with ninja like speed so hurry up and send them something.

 

There is a tach driver on the MSPNP already in place even though most '94-'95 models do not use it. In MegaTune, go to More Settings -> Tacho Output Pin, set it to X2 (JS0). Set it to normal speed, and let me know how that goes.

And yes, the 10 amp fuse removal is only for '93 and earlier.

 

+1 "2I to 1F" kinda. it's actually the opposite of that.

but you won't need the pullup resistor as its already installed. just move the wire on your harness from 1F to 2I. you move the pin on harness instead of messing with the PNP and no worry about ******* it up

 

Probably the same issue when I was wiring my 95.5.... for the EM-B.

Thought the tach wire was 2I... from the workshop manual etc.... turns out was 1F.....

If you look at the harness, you can see if there's the "blank" or the wire really easily....

Dave,

 

Black/White wire on 1f confirmed. No wire on 2i.

Left my laptop at work so I haven't tried changing the tacho output. I'll let you guys know what happens tomorrow.

 

Change your igniter and see what happens. I had the same issue, changed my igniter and now the tach works. (Yes I did unplug it when loading firmware but somehow it still fried)

 

There is no separate igniter on the 94+ cars.

He specifically said the tach works when the stock ecu is plugged in after removing the MSPNP.

 

Ok, it's a 95.5: Wire on 1f, 3 wires to coilpacks.

Matt,
I tried changing the tacho output setting and I still got no tach. What should I try next and what's your take on moving the tach wire over as suggested by Paul?

Paul,
Do you mean actually removing a pin out of the factory connector? How do you remove the pins?

 

Yes but removing those pins can be a bitch. The yellow plastic factory connector opens up and then you can use a very skinny micro screwdriver to release the clip that holds it. Or buy/get a pin, cut the lead to 1F, insert in new pin, insert new pin at 2I.

or spend a lot of money on a boomslang type harness and put between the PNP and the factory wiring. kinda defeats one of the beautiful things about the PNP though.