Hello!
My friend has a Chevrolet Suburban 2500 LT 454 Engine 7,4l BY 1997 with a Vortec Supercharger. He buyed the car complete with the sc installed.

He changed the Distributor and stupidly he loose the correct setting for the cap.

We tried to use a flash light tester but it seems like the ecm works again our settings?

We thinked we find the correct setting, and he drived the car for 400 miles but abruplty the car has misfiring (after 400 miles!?!). The sparks are total black.



Does anybody know if there is a trick with the ecm (it is the stock one)
or anything else to set the dirstributor correctly?

OD is correct.

Best Regards
Juergen

 

when you set the timing, the ecm may have to be put in a base timing mode.

 

...and how it will works?

 

basetimingsearchdoagoggle

 

I´ve tried this, but i did´t find something for this topic:-(