Hey guys,
I'm new to the site but got referred here by a friend who said if anyone could help it would be you. My wife runs an '85 Grumman Olsen step van with a Ford 5.8l as an icecream and snow cone truck. After cold start,Choke and flooding issues I want to set it up with a Chevy tbi to make it more drivable for her. I have a truck to get donor parts, ecm, harness, tb and sensors from. My question is ignition related. Can I use the stock distributor and duraspark module with vacuum advance and not have the ecm controll timing or does it have to have that to function properly. I found a link on this sight about wiring into the duraspark but it kind of eluded to the ecm controlling timing with the duraspark still in. What is the best route?? Thanks in advance

C.W.

 

It isn't so much that the ECM needs to run the spark timing, it is that the ECM requires distributor reference pulses (DRPs) to operate properly.

If the distributor has a magnetic pickup coil use a stock GM 8-pin ICM. That will provide the proper handshake to the ECM along with the proper DRPs. A side affect of this is that the ECM will also be able to control the spark timing (a big win).

Will need to lock the distributor for this to be done correctly. Be sure to get the rotor to cap phasing correct.

RBob.

 

Thanks for the reply. The duraspark does have a magnetic pick up in it and I saw some post on here or a link from here on wiring the Chevy ign module in using the duraspark distributor and pick up. Is he tach signal from the duraspark module not a sufficient signal to the ecm to controll the injector pulse?

 

I have no idea, what is the polarity and voltage level of that signal along with it's relationship to TDC?

RBob.

 

Ok. I think I will try to wire in the Chevy ign module using the ford distributor like outlined in this blog post http://tc.wagoneer.org/2012/08/gm-tb...iring.html?m=1 How do I pin down the mechanical advance? Just wire the weights together with the springs removed and unhook vacuum advance hose?