Team Camaro Tech banner

1 - 5 of 5 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter #1
I posted a question yesterday about my factory tach not working with a stock points distributor on my 69 with an AAW breakerless conversion. I didn't get any response so I'm assuming I stumped everyone also. I did however do some reading on the site with other posts and there seems to be alot of talk about this resistor wire thats with the yellow wire that comes off the "+" side of the coil. I understand that the starter needs 12V to crank but when the engine is started the resistor wire comes into play cutting the running voltage down to 9V to avoid frying the points, which I no longer have. Am I correct so far? When my engine runs it seems to shake alot at idle, smoothing out at 1500RPMs and above, and yes the factory tach doesn't work at all. I have a blueprinted L88 427 and L88 people tell me because the cam is so big it does shake alot. I think this engine is shaking more than it should, it just doesn't seem right. I was wondering if all these problems could be from that resistor wire? If I was to eliminate the resistor wire what would be the best way to do this? I would like to avoid just cutting it until I can pinpint my problem. The only posts I've found reguarding eliminating the resistor wire are talking about MSD, Mallory and Pertronix systems, nothing about that AAW breakerless conversion. Any input would be greatly appreciated. Thanks again guys.
 

·
Super Moderator
Joined
·
32,349 Posts
Best route to take to eliminate the resistive wire would be to fold back the wire in the engine harness and tie it off to prevent it from touching other surfaces. Maybe even put a length of shrink tubing around to insulate it.

Then, run a #12 AWG wire from the fusebox spade labelled IGN. Measure it to be sure it only has voltage during IGN. After confirming proper action, run the new ign wire from this spade through the firewall, grommeted hole, to the + terminal of the coil. Attach yellow wire with it.

Tach wire goes to - terminal of coil or to TACH terminal/wire of new ignition system depending upon manufacturer. Follow their instructions.

L88 camshafts are lopey. Confirm all cylinders firing by either placing a drop of oil/WD40 onto each header tube and see it evaporate or read each tube with a temp gun, aka, 400°F or more. Adjust carb mixture screws using a vacuum gauge and adjust for the highest reading. Maybe alittle more initial timing, i.e., 10°-12° BTDC, but not enough to kick against the starter when hot.
 

·
Premium Member
Joined
·
22,122 Posts
Another way to verify all cylinders are firing consistently is to just hook the timing light to each wire in turn and look for that nice steady flash.

Most breakerless conversions require you to remove the resister wire. As AAW is in the wiring business, you might ask them about that.

Tach needle doesn't so much as budge, huh?
Did it work before you switched ignitions?
This http://www.camaros.net/techref/electrical/tachfilter/ is a tachfilter you can build. I dunno if it will help a dead needle.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #4
Well I spoke to Donny at AAW today and he said he hasn't had anyone question the breakerless conversion they sell with factory tachs before. He said the system is designed to work WITH the resistor wire in place. But as far as the tach goes, he suggested a "inline tach filter". I really don't understand how that will help because to the best of my knowledge tach filters straighten out erratic tach readings, I'm not getting any reading, unless the system is sending a signal the tach completely doesn't understand and the tach filter translates it so it will understand it...I'm just stumped. The car originally came with a tach but it was gone when I gought the car and I replaced it with an OER one. I wish there was a way of bench testing it. My other car has an MSD setup, so that won't be much help either. I guess if I pull the plug out of the back I can test the pink wire and make sure it's getting power. Any more input would be appreciated.
 

·
Premium Member
Joined
·
22,122 Posts
The tach filter I linked above has helped a LOT of tachs over the years, but if anyone ever brought back a dead needle with it they didn't tell me about it.

Tach filters get rid of stray high frequency noise, and send the tach a nice smooth square signal. One might help here. If it was mine, I'd pull it out, get some wire, and "Bench test it" on another car.

The tach lead on the msd should run it, but do not hook it to the coil neg on an msd equipped car.
 
1 - 5 of 5 Posts
Top