how new is the hei module. the first one i tried to use was burned and would not work. i got another and it cranked.

 

Did you bypass the ballast resisitor?


Otherwise, dunno what to say, I am still using the same hei setup and IMO, its the best thing I have done to the truck. Might be a faulty module.

Oddly enough, I grounded a spark plug a couple months ago, cannot recall what for but I had a very strong blue spark as I recall, using the hei setup.

Good luck

 

cant seem to load up pics need to see them

 

Go to this link...

http://www.carbdford.com/tech/HEI/hei.htm


If you have any questions use the address at the bottom of the page, your questions would be answered better by that person. later

 

While this conversion can be done and it "works", just not as well as the OEM DS-II system, it is best to find the fault in the DS-II system and fix it. With this conversion you will have a bunch of "haywire" connections in your vehicle that will be a problem later on.

 

Define haywire connections.



I agree if you have a problem fix it first.



However, I replaced a fully operational duraspark II ignitions system, everything, with brand new duraspark parts, distributor, coil, module, etc., felt no difference, less than 5000 miles later I do this gm module conversion just to be doing it (nothing faulty with the durasparkII at all) and it made a noticable difference, in my experience.

 

If the DS-II system was working you will get no (none, nada, zippo) improvements with another ignition system, either GM or aftermarket. In fact, the hot start retard function built into the DS-II module will give better starting under those conditions than the GM conversion or aftermarket systems. Any "improvement" felt means that you had a fault in the DS-II system. The guys at most parts stores will not tell you this. They want to sell you parts and high $$ aftermarket systems.

 

Well junkyard route and if you have the DS II distributor, it might cost a total of $20 to try it...new parts, less than $40 if you have the DS II distributor.

I would like to agree with you, that there should have been no change but from where I sit, there was. IN my experience, the timing could not have been dialed in any better, the parts were replaced and as far as I am concerned, the DS II was as good as it could possibly be (remember I used two seperate DS II coils and two seperate DS II modules). I used the same distributor as it sit, did not touch the initial - vacuum advance - or centrifugal, I used the same power wire for the GM module that was run to the duraspark module, and the same connections on the distributor for the tfi coil, as were used on the DS II coil. Plain and simple, she fired quicker and idled smoother on cold starts. Its not easy to see the benefits of an ignition in seat of the pants but when it comes to starting a cold carbed engine, it is noticable, at least it is from my experience.

The first time I replaced all the DS II parts, it was more or less maintenance, as I put a newly built engine in and figured why not, the parts weren't changed due to being faulty. Then I went with the GM module, after I asked around about an msd, someone said go look at the GM conversion link you might wanna try that first, I did and couldn't be happier with it.

Who knows? later

 

You had a fault, plain and simple. You bypassed it or fixed it somewhere when you did the conversion. You will not get any improvement, starting, running, or otherwise with any other system period. You can read this article, copy and paste the address:
http://www.centuryperformance.com/timing.asp

 

tfi coils are better than the durasparks coils.

 

Actually the TFI coil is made to run at full ignition voltage without an external ballast resistor. I do not know if it has an internal ballast resistor. It is a nice coil but I am unable to tell if it has as much voltage capability under reduced voltage as the DS-II coil. If it has a ballast resistor built in it will not give the same performance as the DS-II system coil. In the DS-II system the ballast resistor is bypassed for starting. It does not matter a whole lot since the spark voltage is determined by the spark plug gap and not the coil or other component's voltage capacity. I may check out a TFI coil on my truck tho since I have a good used one. I also have two DS-II coils, one almost new and the other one is new. It may depend on which one mounts the best with my dual snorkel air cleaner. I do like the coil terminal on the TFI coil better also.

 

Well if I am mistaken then so are the others who have tried this.

Lets say for a second that I did bypass a problem (which didn't exist) and it runs better now, it was the best $40 I could have spent.

You would really freak out if I told you I was running full direct vacuum to the vacuum advance at idle, which is pushing it to well over three times the recommended initial, then you would probably tell me how I would have trouble starting the truck due to the overly advance timing....then I would have to disagree once again.

It is what it is, I know exactly what your trying to tell me, I know why it shouldn't have made a difference but in my experience...it did, each component had the right voltage etc.. Who knows?

 

I run full manifold vac also on many applications. It is better for load sensing but then you may need to increase your total mech advance and decrease your vac advance. When I get into that territory there is lots of trial and error.

I have seen the same thing you experienced many times tho on vehicles, equipment, and many other machines. There was a problem and you bypassed it or "fixed" it. It is good that it is running now. Just beware that gremlin could pop up again.

 

Fair enough...anything is possible. later