Dunno if what I've done is holding me back or not. Two years ago, I pulled the 305 TPI and swapped in a 350 carbed. I have not changed the ignition from the original factory setup. Now, some threads I have read have lead me to realize that I may not be seeing the full potential of my motor due to using the computer controlled ignition which (now that i know better) may be in limp home mode due to the lack of input from the now absent TPI related sensors. Is this a problem for me?? I also recall seeing somthing saying that my TC lockup is not functioning now?? Any answers/comments/suggestions would be greatly appreciated.

Thanks,
Adam

 

The ignition is holding you back.

Your transmission is on borrowed time if the TC hasn't been locking up (which it hasn't been).

 

Is it the trans itself, or the TC that is in trouble???

And regarding the ignition, can anyone recommend a good unit on a for a reasonable price? The only component I have now is the Mallory standard HEI distributor.
http://store.summitracing.com/partde...0&autoview=sku

I'm just beginning to get a grasp on ignition systems, so a breakdown of what components I need would be a big help as well as greatly appreciated.


Adam

 

You'll burn out the transmission 3-4 clutch pack if the TC isn't locking up.

That distributor will work fine. It will drop right in place of the stock distributor and even hook up electrically the same. You won't need the flat 4-wire connector that goes to the firewall harness.

You can find less expensive HEI distributors on eBay. I've seen them for as low as $65 shipped. Quality is more of a crapshoot, but feedback seems to indicate they're selling a decent product. The Mallory is a good bet, though.

 

So was I correct in assuming that my ECM is still trying to control my spark timing while in limp home mode? Will this ignition control box solve my problem? http://store.summitracing.com/partde...5&autoview=sku

Can I expect a noticable gain after this upgrade? Also, how do I remedy the TC problem??


Adam

 

Don't need the box.

You can purchase a kit to control lockup or do a search here to find the parts you would need to wire it yourself. Probably won't save too much (and more aggravation) over spending the $70 or so for a kit. Check your Summit or Jeg's catalog.

Your problem now is that the ECM is no longer receiving the sensory input to tell it when, and how much, to advance your ignition. The MSD is a good unit although more expensive than some. If you have an Autozone, Advance Auto, or one of the others nearby you can usually order the dist you want from them and save on shipping. If it's bad or the wrong part you return it to the store. Sometimes beats the E-Bay crapshoot or the RMA thing through one of the mail order chains.

 

I want to keep the Mallory dizzy that I am using now. I just need to know what I need to have the ignition advance properly. I don't care about the ECM anymore, as far as I know, if it is not controlling my ignition properly, then I don't have a use for it. Sorry if I've been too vague or confusing, but like I said, I'd like to get the ignition right so I can move on to other probs or mods.

Now, I understand that I can fix the TC with the kit. You are telling me now that I don't need the aftermarket ignition box to properly operate my ignition advance?

Thanks for you guys' time and knowledge,
Adam

 

Which is it - stock, or Mallory?

 

All stock with the exception of the Mallory dizzy linked in my second post. No other components yet.

 

Then you've got all you need.

 

So my timing is NOT being affected by the ECM even though the dizzy is plugged into stock wiring harness?

 

I too was confused. First by your statement: "I have not changed the ignition from the original factory setup." and evidenced by my statement: "The MSD is a good unit although more expensive than some."

I stand behind what I said earlier, 10-bolt rearends are a dime a dozen at the yards around here....

 

I'm sorry for being so confusing, but I still don't have the answer to my question. Now that I have swapped the original 305 TPI for a carbed 350 with the mallory dist(powered by the original factory wiring harness which is still connected to the ECM), is my timing being adversely affected by continuing to use this original igniton system? Or, do I need to upgrade the entire system to stand alone (without ECM and orig. harness)? If you know the answers to these questions, I would be SO grateful. Thanks,
Adam

 

The distributor you linked to should only be receiving a 12 volt feed from your wiring harness. The ECM commands the distributor through the four-wire connector which should not be hooked up to your dist. There is another Mallory stock-style dist that will work from this connector, though. Provided you have the model dist you linked to the ecm IS NOT talking to it. You still need to verify that it's working correctly though. The timing advance on your dist may need adjustment, may be broken or your initial timing may not be set correctly.

To verify that it's working correctly and to properly set it up there have been some recent threads that provide some good info. Notably:

https://www.thirdgen.org/forums/tech...g-advance.html

You may also want to check the Mallory website and attempt to download a manual for your dist. Should be able to provide specifics to your model, if available.

Missed your last post right before mine. It takes me a while to type with the one finger.

 

Thank You, I will check.

Adam