Scotts97C4

On my 87 base coupe auto with a new 350ci/330hp Crate Engine.
I'm having issues with the external spark control.
I would like to make it a stand alone type HEI.
I tried changing the module to the old style 2pins on each side.
And it worked great for about 8 sec's then the car died.
I figure its tied into the ECM and it shut it down.

(It was amazing the car started before I stop'd turning the key.)

Has anyone else done this conversion?

vetteoz

What issues?

Unlikely it would run with a non CC HEI ( and the TPI ) because the ECM needs the input signal from the dist in order to fire the injectors

My1991

You originally had hei/est no way to make the ecm control spark on a hei with vacuum advance.

Scotts97C4

I don't want the est. Or vacuum advance.
I'll just degree it in and run it that way.
Does MSD have a conversion?

Benny42

Your ECM needs distributor feedback to run the fuel pump. It won't run well with no
advance, the system is too integrated to just throw away.

vetteoz

Fuel pump is fine ,will run off the OP switch; it is the injectors that rely on the signal to the ECM from the dist.

Alternative is to install the F.A.S.T EZ system that has electronic fuel control with a non CC dist so you can run purely mech advance like the OP wants to

Rohn

[QUOTE]I would like to make it a stand alone type HEI.
[QUOTE]

Why?

Scotts97C4

[QUOTE=Rohn;1584432114][QUOTE]I would like to make it a stand alone type HEI.
Because every TPI I have seen has issues with hard starting.
It Shouldn't take 2 seconds or more to start the engine.

When I changed it to the stand alone it started as soon as the engine started to turn over.

The extrenal spark control lacks to say the least.

I did the same thing to an older chevy and it made a hugh differnce.
But it didn't have the spark control on board the ecm.

Rohn

That may be related more so to fueling. I was not aware of any deficiencies in the GM HEI/ESC. As good as aftermarket.

bjankuski

I agree, this is a fueling issue, you probably need more cranking fuel. If the fuel is dialed in correctly it will start immediately.

Scotts97C4

I orginally thought that but I replaced the filter.
Then check fuel presure it runs at 39 psi., then leak down went to 37 psi over night.

bjankuski

The engine is not stock it probably needs more cranking fuel in the tune then the stock engine. You could also have a bad cold start injector.