MSD and the 85 Supra

[csuprafreek]

Has anybody had any problems out of the MSD installs on a MKII? I have a 6m with 2 1/2 inch ex., headers, MSD complete unite except for dist. and I am getting Tac. bounce idle speed. Has any one else had this prob. And I am not getting but about 14 mpg. I have tried diff ECU's, different AFM's and all but pulled my hair out, I have even swapped out the MSD unit once... HELP!!!!!!

[grahamus]

Don't our toyotas need a special tach adapter or something like that to make the MSD work correctly?

[Solo1Supra]

Granted it's a year off, but I had an MSD 6 in my 84. I had to use a Tach adapter to get the tach to work, but it never bounced at idle. Needless to say I took it out one day when the damn thing wouldn't start, the MSD toook a dump for no reason at all.

[csuprafreek]

It has the whole set up,MSD tach adapter,MSD coil, MSD main box MSD wires...the whole set up...

[SilverMk2]

The next question is do you have the correct tach adapter wired in correctly?

[joefoe]

I bet you have some interferance in the ground or the + wire going to the tach adapter. What cercit do you have the tach adapter wired in to? As for your mpg, you said you have headers, do you have a o2 sensor in them?

[csuprafreek]

Yes I got the header from Rappid Chimp, the whole set up is wired like MSD says to. Has anybody had this problem...anybody ,,, anybody BULER....? Thanks guys, keep those anserws coming...CHEERS!!! LEE :-)

[StanS]

If it were me. I would remove the MSD and get the mileage back to normal via troubleshhoting and repair. As suggested above you may have a bad Ox sensor causing poor mileage. I'd put the MSD back in after I resolved the mileage problem. You don't want to add a mod on a broken setup. It only makes the troubleshooting much moe difficult.

[csuprafreek]

The O2 sensor is brand new , yes it is a Denso....I did put the stock ignition system back to factory today, I think the MSD is not ment to be in the SUPRA :-)

[Solo1Supra]

On a bone stock engine, it's a waste of money, just my opinion....
Switching to an Accel 140008 coil is a better choice.

[mr toytech]

ive got the msd6al on my 84 and its beed trouble free for 6 yrs. but , in the begining it quit after 3 hrs and a limiter bump in 3rd and it was the wromg tach adapter sold to me and they replaced the box for free at the place puchaced.

[csuprafreek]

Well it's not really bone stock but I guess it could be considered stock. It is a 6MG, with headers and a 2 1/2 inch ex. So I guess it really is stock... :-)

[Darrow]

Why does the supra need a tach adapter? Does the MSD replace the igniter? On an 86 the tach signal comes from the igniter. I know with the Jacobs ICE system there is no need for a tach adapter. But the jacobs doesn't repace the igniter.

[csuprafreek]

it woin't run without an adapter....this is making me nuts..... :-)

[csuprafreek]

Yea my tac adapter went out after about ..well less than 10 hours,however the Tac issue has never been right!!! :-P

[AJ]

I have wiring schemetic at
http://members.aol.com/aj9o4/Supra/

Under MSD

MSD does have an issue with heat soak, thats why NASCAR has them mounted inside the cab not the engine compartment.

MSD does not replace the ignitior in the MK2.

[Darrow]

MSD does not replace the ignitior in the MK2.


So then why do people need a tach adaptor, since for the 85/86 atleast, the tach signal comes from the ignitor?

[Solo1Supra]

My 84 wouldn't run without the tach adapter.

[AJ]

IIRC your mounting the tach adapter between the ignitor and coil, and need the some sort of signal to "fire" the ignitor??? The tach adapter besides providing a tach signal also allows the ignitor to fire.

[Solo1Supra]

If I could draw worth a damn on a computer, I'd lay out how I had mine installed.

[csuprafreek]

If you could get that it would be great....I would really apprechiate it! :-)

[mr toytech]

pm sent on tach adapter hook up. any other questions let me know.

[bowtiebuba]

how do you wire the msd in?

[ddd228]

On a bone stock engine, it's a waste of money, just my opinion....
Switching to an Accel 140008 coil is a better choice. NO MSD for the 5MGE? A better choice is a hotter coil,instead? Hmmm. The reason I ask this is that trouble that Solo is having with tach bounce. Adapters,ground fault,etc. Why cannot a MSD be used as a clean bolt on?

[CelicaSUPRAMK2]

Well, from a friend of mine that works at Schucks Auto Supply who owns an AE86 Trueno, the only way he was able to get the MSD coil to function properly is have the tach bounce and ignition control. After testing his car out with these new products he said he didn't feel any difference in driving performance. However he did say the change made a GREAT difference in fuel economy - an additional 5-8 mpg!

[Don L.]

Maybe not significant, but i recall I also needed a small in-line diode to get my MSD 6AL to work on my '84.

Don L.

[boomostik]

I work at Advance Auto Parts and got a 6AL. You all have said that it does not replace the ignitor. However my dilema is I got the box for free and the cheapest ignitor I can find is 55 dollars. From looking at the wiring diagram it looks like the box receives the signal from the Pentronix unit (magnetic pickup) inside the distributer. So I am going to try to hook up the box without the ignitor to see if I can get the car started. The guages don't matter to me. I have all aftermarket guages except the fuel and Speed. I'm going to put this on in the morning and see if I get any fire. I'll let you know.