Topic: My new T/A

[4wheeling79]

The last few days I have been working on my new ride as much as possible and getting to know it. The tach will need replacing it will not work wiring is good I check it with another tach and it worked. (Any ideas on this?)

The AC system although it isn't charged I am positive if it where it would defiantly blow cold air this is what worried me the most about the car. It did take the better part of the day to figure out all the wiring as it was not finished I got it all in place and working. Awesome!

Upon driving the car when I picked it up I could no help but wonder why it was such a DOG! This car had trouble getting out of its own way no power and had defiantly concerned me. So this evening I cleaned the carb fixed a vacuum leak and re set the timing. (It was at 0 degrees) I set it at 10 degrees and took it for a spin the more I drove it the better it ran so much that from a 15mph roll it tires will go up in smoke! Night and day difference I am totally amazed this thing will move!

Tomorrow I am going to do a tune up with plugs, wires, cap and rotor is there any thing I need to do in the distributor. Like change the coil or the control module? Let me know any thoughts on this.

Thanks!

[marx3]

If you change cap, rotor, wires, plugs and cables and maybe the vacuum canister if it is bad, there is not more to replace when servicing. Afaik control module and coil are either working or not. They dont get worn like the cables and such. When you are doing a check to be sure the engine is running properly, check the front vacuum can on the carb. See if it engages when the engine starts up. If it doesnt you need a new one. Get a new one from cliffshighperformance.com or from quadrajetparts.com.
Regarding timing: it is supposed to be 18 degrees initial from the factory, and you can bump it up a few more with out hitting detonation, when running stock vacuumadvance canister.
beeing at 0 degrees kills any car that is not computer controlled :-) Get it up to 18-20 degrees and get ready to buy new tires sooner :-)
Nice car, do you have pictures?

[winks79]

You can send your tach off the Daniel at Gaugemarks. I just sent him mine and got it back working like new now. Here is the web address, give him a call sometime between 10 and 1 eastern time. http://gaugemarks.com/

[4wheeling79]

Here she is thanks for the help! I did change plugs, wires, coil, module, and oil one of the items did make a difference runs even better. So initial timing on these cars should be 18 degrees? I reset it this week end and I'm at 10 degrees now.

[marx3]

Nice car. Yes sir. 18 degrees. believe it or not. It also says so on the emissions decal in the enginecompartment.
Changing all those things definately could make a difference if the parts replaced where worn. But timing beeing at 0 degrees will kill power in any old engine. Try putting it back down to 0 and see if if doesnt turn back into a dog :-)
18-20 degrees it is!

[Grand73Am]

You haven't said what engine you have. It is 18 degrees advanced, IF you have an Olds 403 in it. Not if it's a Pontiac engine.

Also, vacuum advance should be connected to manifold vacuum(after you adjust the timing).

Nice car!

[marx3]

Well, Haynes states that automatic 400 requires 16 degrees initial, 18 degrees for 220 hp version, 403 actually requires 20 degrees.

I garantuee you it wont matter anything or hurt anything to put either of these engine at 18 or 20 degrees initial.

[Grand73Am]

The Haynes is wrong about the 403 then. I have 2 79's with 403's and the emissions sticker says 18. I've tried a little higher, but it didn't like it...idle deteriorated. 18 was perfect though.

[hada76]

you may have to try a few different settings to see which runs best for you.

[marx3]

It may be wrong, I am not claiming it to be the 403 bible :-)
My point is, OP needs to get his initial up about twice as high.
Grand73am: how high did you set you initial before your idle deteriorated?
The biggest problem with the stock HEI is that the vacuum can advances the timing alot. You can seldom set your total up to the desired mid 30's for best power without running into detonation, hesitation and suffering idle, because the vacuumcan usually gives about 25 degrees of advance.

[Wallington]

It's the 400 W72, the W72 guide says these were set at 18 degrees over 16 degrees of the regular 400. But that may not be the best spot for you engine if already been apart, even the last of the '79 W72 cars were set at 20 degrees. Sneak it up until it stops being responsive, find the sweet spot!

Pic from his other posts:


If you've tested other tachos on the same wiring then it simply comes down to faulty tacho, you knew that already. The most common cause is the circuit board on these fails. Luckily you can unplug and swap this over and resolder two wires, should you find a working tach that has a rough face, or simply swap an entire unit in. I've just done this myself, was previosuly rewired with an aftermarket external circuit board, which was fine, but I had spare tachs to swap parts between to get a good one.