97_Roadrunner

iTrader: (2)

I've tried to plug my msd 8969 rpm window switch today.
Everything seemed to be right until I started the engine.
No rpm reading "0" displayed!
Now, +12v(red) and ground(black) are hooked on the cigar lighter,
as it's powered by the ignition switch.
(I've hidden the msd inside the drawer above the ashtray.)
The normaly open output(yellow) is hooked to the VI's solenoid, while the normaly closed output(grey) is left unused.
Finally, the tach signal(white) was first hooked on cylinder #2 coilpack ground wire.
(The one noob's call cylinder #1 on the front bank! hahha!)
But no rpm... I didn't panic and tried on the "info" wire from the ecu... still no rpm...
I bought the msd from XJinCT and it seemed in great condition and was very well packed, but no manual.
Since my swap is quite rare, 3.0l cams and 4spd auto.
I've set the VI to close at 1800 rpm and re-open at 4300 rpm. (Stock rev limiter)
"On cylinder" setting was already set to "6" but changing it to "1,2...6" haven't changed the tach reading at all.
"0" still displayed and of course, the VI is not working.
So..... can anybody help me on this?!?
Thanks twice!

gtr_rider

iTrader: (50)

Pull your cluster out, and put the RPM signal to the TAM screw behind the gauge cluster. Problem solved

97_Roadrunner

iTrader: (2)

I totaly hate to pull the cluster out. I've done it too often. My wiring is already in the engine bay. So does tapping the tach signal on the transmission's rev sensor wire, will make it work?

gtr_rider

iTrader: (50)

cutting corners just makes it more work.. just tap into the cluster, thats a clear cut source for RPM signal.

JClaw

iTrader: (17)

No need to pull the gauge cluster. It's the same as installing an aftermarket tach. On a distributor-less system like the 4th gen and up (coil on plug), instead of tapping the RPM signal wire onto a coil pack ground, you need to tap that wire onto the signal directly from the ECU.

Pin #5, White wire with a green stripe

grey99max

iTrader: (12)

I do the same thing with a under-the hood MSD 8969 to control some relay logic to switch over my MEVI. I believe the center wire on any coil connector will do what you want. Mine's connected to #4's coil. Works great.

I also use another 8969 (inside the cabin) connected to the Tach output from the ECU (pin #5, I think) and the MSD works fine there - programmed to 6 cylinders of course.

Tatanko

iTrader: (34)

I'll reinforce what's already been stated: either pin #5 on the ECU or go for the TAM screw. Personally, having done both ways, I think the TAM screw is much easier than crawling around in the passenger's foot well. Go for either one of those and you eliminate the guesswork and headaches.

97_Roadrunner

iTrader: (2)

I tapped on the tranny's rev sensor's white wire. As it is THE SOURCE of tach signal, and guess what.... nothing again.... aaaaarrrrrggh! I did lost the tach signal while doing the swap. I belived that it was cluster related, since it didn't cause drivability problems. But now I start to belive the rev sensor died on me. What you guy's think?

BTW JCLaw my tranny shift well now! And pm me your phone number again, I need to call you.

Tatanko

iTrader: (34)

GO WITH OUR SUGGESTIONS. Trust us, we have experience, we know what we're talking about

If your rev sensor was dead, I doubt the car would function...period.

97_Roadrunner

iTrader: (2)

Still no luck...
Ok, now I've tapped on ecu pin #5 (tachometer) and nothing again.
+ I've extracted ecu's codes and I got: 1207 Engine Speed Signal.
Did I was right when I sayed my rev sensor was dead?

Tatanko

iTrader: (34)

You could very well be correct, or it might be disconnected somehow. Make sure all the wiring is perfect/in tact before you replace it.

Maybe I was wrong about the car not functioning

nismology

iTrader: (8)

If the crank position sensor (POS) was dead the car wouldn't run, like tatanko said. Simple as that. There's either something wrong with the ECU's tach output itself or the post-ECU wiring has been compromised. Perhaps even the CPS's wiring has been slightly compromised, but not enough to prevent the car from running.

What I'd do next is test the voltage at pin #5 during warm idle. It should be ~7V.

97_Roadrunner

iTrader: (2)

You make me remind that when I first started when I swapped, it wasn't firing up. JCLaw taught I screed-up the wiring, but I made him shave more material off the oil pan, so the CPS would sit further inside. It made the car start. Maybe the CPS is still a bit too far outside.... Swaping the VQ30 oil pan could fix that...

nismology

iTrader: (8)

Thing is, if the car is starting up and running at this point, the ECU is getting all the info it needs to output a tach signal to the guage cluster. This is strange indeed. I tried looking up the DTC that you posted (1207) and I can't find it.

97_Roadrunner

iTrader: (2)

1207 = DTC P0725

Page 69 in FSM AT section (automatic transaxle)

nismology

iTrader: (8)

Didn't realize it was an AT code. In any case, the problem is with the ECU's engine speed output. Like I said in post #12, you should start by checking the reference voltage at ECU pin #5. That will determine whether the problem is with post-ECU wiring or not.

deletedalien

Subscribed.

NmexMAX

iTrader: (22)

Might not do any good since this thread has been inactive for the past 9 years.

deletedalien

well... dammit....

so has anyone figured out how to add an aftermarket tach yet?

Mattx

iTrader: (2)

Yea you have to look in the 5th gen stickies

NmexMAX

iTrader: (22)

Aftermarket tach is easy, not sure why you'd want to but yeah, you just need a +12v and a ground, and either the signal wire from one of the coil packs or the tach wire from the dash. I'd recommend the signal wire from the coil pack so it's more accurate. Any of the AFC/EMU wiring diagrams would have the ECU wire callout. Or an FSM.

Mattx

iTrader: (2)

Not sure why anyone would want one either unless they need that badass light to come on so they know when to shift😂.