LT5 miss at all speeds - ZR-1 Net Registry Forums

Big D · 07-18-2015

I have an unmodified 90 and I have the 90 SM. I went to the library and got a diagram for the primary circuit which shows the primary wiring and the "splice S127" i believe. I also have the LT5 Fuel and Emissions Course book which is somewhat helpful. Not sure what my next step will be, was thinking turning it over and checking to see if i am getting voltage to # 6 at the injector. Shouldn't take but a couple of turns to verify. From the schematic it looks like i should be looking for a ground from the ECM on terminal A of the injector. Since i can shoot the wire from the yellow ECM connector to the injector and it is good I should be able to look for the ground on the back of the ECM while i turn it over, doing this would also NOT fire the left bank injectors since I haven't removed their electrical connectors, thus avoiding sending fuel into the cylinders. Also will check for 12 volts on the B side of the injector with the key on. Hope to look at this tomorrow if the chores don't overrule.

07-18-2015	#18
Big D Join Date: Jun 2014 Location: Washington state Posts: 17	Re: LT5 miss at all speeds I have an unmodified 90 and I have the 90 SM. I went to the library and got a diagram for the primary circuit which shows the primary wiring and the "splice S127" i believe. I also have the LT5 Fuel and Emissions Course book which is somewhat helpful. Not sure what my next step will be, was thinking turning it over and checking to see if i am getting voltage to # 6 at the injector. Shouldn't take but a couple of turns to verify. From the schematic it looks like i should be looking for a ground from the ECM on terminal A of the injector. Since i can shoot the wire from the yellow ECM connector to the injector and it is good I should be able to look for the ground on the back of the ECM while i turn it over, doing this would also NOT fire the left bank injectors since I haven't removed their electrical connectors, thus avoiding sending fuel into the cylinders. Also will check for 12 volts on the B side of the injector with the key on. Hope to look at this tomorrow if the chores don't overrule.