Jay7199

I have a 84 that i did a carb conversion on, i got a mechanical/vac dizzy that has a 5 pin HEI module installed, The car is freaking out and sputtering around 3000RPM.. I think its the module.

I used the factory connector that went into the 7 pin module dizzy and hooked it up too the vac advance with the 5 pin module..

What do I need to do to eliminate the retard in the 5 pin module and does the large flat 4 wire connector need any modifications?

Thanks

oldalaskaman

convert to a ...'4'...pin module dist.?

Jay7199

What's involved in swaping a 4
pin module in?

oldalaskaman

buy a cheap hei dist, hook it up to 12v switched, good to go

Jay7199

Any way to just put the 4 pin module in my current distributer? I'm sure there is, just need a little help with the wiring

oldalaskaman

the 5 pin module has the knock sensor in it, if the 4 pin will physically plug in to the 5 pin plugs , that should eliminate the knock sensor cause there wont be a plug for it and the module wont be spazzing out. . and ...probly run ok. post this in C3, I've used the gm hei on fords , toyots, bmw's , honda's, etc. but as cheap as they are , I just go buy a complete dist, when it comes to chevy's. eliminates all the b.s.

Jay7199

W and G on a 4 pin HEI module just go into the pickup around the distributor shaft?

So if i just left the large flat 4 wire connector off it should work fine correct? problem is that it won't start if that is disconnected.. Is the ECU killing spark some how?

oldalaskaman

post in C3, you're trying to make a 7 pin plug work on a 4 pin, good luck

rodj

If you have a carb you don't use the stock ECM, it should be disconnected because it plays no part anymore in engine management

Jay7199

I know it doesn't do anything anymore, The only reason I said that is because the ECU and wiring are still in place for now and im not getting spark unless the EST is pluged in.

oldalaskaman

I posted a 4 pin diagram in your other thread in C3, hope it helps

War Vet

Couldn't he just put a cost friendly ignition box in place and solve all? Should be cheaper than a new hei and it will help his current hei as well.

Jay7199

what like a 6A box?

War Vet

I replaced my MSD 6AL box with this summit box when it went out on me. No problems at all.

http://m.summitracing.com/parts/sum-850610/media

If you download the installation instructions and scroll down to the GM hei 4,5 and 7 pin modules you will.see how easy it is to install.

Jay7199

I just wired in a 4 pin module, runs good now! still need to tweek the carb and total advance some more, But im happy.

oldalaskaman

War Vet

Awesome!!!!!!!!

383vett

In the last few months, someone posted a picture of the internals of a Summit MSD lookalike vs the actual MSD 6AL. Might want to search it out and have your old MSD refurbished.

War Vet

No issues with it, that's what matters overall.