poor tach signal ford tfi

feldz82 · Post by **feldz82** » Fri Jun 02, 2006 9:07 am

is there a way I can test the ignition input and output to see if I have them correctly assembled? I have a stim I can use.

MegaScott · Post by **MegaScott** » Fri Jun 02, 2006 1:52 pm

You can only test the MegaSquirt on the stim for ignition input, the ignition output you'll have to measure with a scope or add the circuit in the assembly manual to your stim for ignition output. Your problems are on the PIP input, so plug your stim into the Megasquirt and test it, you should be getting a rock solid tach in Megatune on the stim. While your at it test everything else, you should be able to pull up the realtime display and vary all the pots and get a response, if not you need to look into the reasons why.

See the MegaManual - http://www.megamanual.com/v22manual/mtabcon.htm

Troubleshooting - http://www.megamanual.com/ms2/V3trouble.htm

Ignition triggering - http://www.megamanual.com/ms2/Ignition.htm

feldz82 · Post by **feldz82** » Sat Jun 03, 2006 9:02 am

I plug the stim in and ran realtime display. I get a good tach. rpm goes up when I turn both pots. I did the stim mod for the output and the led pulsates at lower rpm. the led shuts off at 0 rpm. I currently have r43 in, do I need to jumper that? I'm assuming the megasquirt should be fine. when I wired up the ignition I used diyauto tunes remote tfi diagram. I took the pip directly from the tfi into pin 24, and i splice pin 8 of the distributor connecter into the pip because it looked like pin 4 and 8 were jumpered. I connected the spout to pin 36. I have pin 4 of the tfi powered in run and start to the coil and pin 1 of the distributor. pin 3 of the tfi is power in start only. Pin 5 of the tfi I have going to the negative side of the coil and pin 6 of the tfi into pin 3 of the distributor. The distributor shows ground at pin 2,6, and 7. does this sound correct?

feldz82 · Post by **feldz82** » Sat Jun 03, 2006 9:12 am

And does the shielding on pin 24 of the db37 need to be grounded? I tried it both with and without.

MegaScott · Post by **MegaScott** » Sat Jun 03, 2006 3:14 pm

feldz82 wrote:I plug the stim in and ran realtime display. I get a good tach. rpm goes up when I turn both pots. I did the stim mod for the output and the led pulsates at lower rpm. the led shuts off at 0 rpm. I currently have r43 in, do I need to jumper that? I'm assuming the megasquirt should be fine. when I wired up the ignition I used diyauto tunes remote tfi diagram. I took the pip directly from the tfi into pin 24, and i splice pin 8 of the distributor connecter into the pip because it looked like pin 4 and 8 were jumpered. I connected the spout to pin 36. I have pin 4 of the tfi powered in run and start to the coil and pin 1 of the distributor. pin 3 of the tfi is power in start only. Pin 5 of the tfi I have going to the negative side of the coil and pin 6 of the tfi into pin 3 of the distributor. The distributor shows ground at pin 2,6, and 7. does this sound correct?

You can leave R43 in or jumper it, makes no difference. You should not install R57.

Just to refresh my memory, I put up the diagram, I've never done a remote mount TFI, but others have done it per this diagram with success. From what you said, your wiring sounds correct. Do you have a grey or a black TFI module?

feldz82 · Post by **feldz82** » Sat Jun 03, 2006 4:48 pm

I have the black module. for the ignition relay, is that 12v's in run or run and start? I have it wire run and start. I took the original pip from pin 4 of the distributor and spliced it into pin 8 or is pin 4 not needed? I replaced the distributor with a new one. the coil still produces spark. that leaves the tfi module. Is there a method to test the tfi? I also checked the board and noticed the 1k resistor in d2 was backwards. would that make a difference?

MegaScott · Post by **MegaScott** » Sat Jun 03, 2006 5:43 pm

Ah, you have a Computer Controlled Dwell Module, or CCD.

They are slightly different than the grey push start module.

1. The CCD does not control dwell, you will need to restrict your dwell settings to ~3ms so as to not over heat the module and the coil.

2. Pin 4 on a grey push start module is for the start bypass signal, The black CCD modules use pin 4 for IDM back to the EEC, therefore you need to remove your +12v in start wire from pin 4, that could be shorting out your spout which would cause problems.

EDIT - The orientation of resistors doesn't matter.

MegaScott · Post by **MegaScott** » Sat Jun 03, 2006 6:00 pm

I see a problem with the above diagram, the TFI connector is numbered backwards, I will correct it. If you wire it up as shown as looking into the end of the connector, you should be good, except leave off the Start wire on pin 4.

feldz82 · Post by **feldz82** » Sun Jun 04, 2006 10:57 am

do you think I might have burn out the tfi by now? I try this out today and let you know what happens

feldz82 · Post by **feldz82** » Sun Jun 04, 2006 6:40 pm

still no luck. I'm going to replace the tfi. I'm gonna try to get a distributor with the tfi mounted on to maybe simplify things