Thread: No fuel past injectors 90 GP 3.1L-Ignition amplifier and switching module??

anyone ever hear of a ignition amplifier and switching module on a 1990 grandprix with a 3.1 in it?

I'm looking in Haynes manual page 12-27....

The problem i'am getting is im not getting fuel past the injectors... I'am assuming all my injectors did not go bad at the same time. The only 2 problems i could see it being is either the ECM or the ignition amplifier and switching module.

I have almost 50psi of pressure up to the injectors so its not fuel pump, filter, or regulator. (Regulator was just changed about 4k miles ago.)

What happens when this module goes bad anyone know?

Also the crank sensor was replaced because i thought that was the problem, but obviously did not fix the problem.

I will pay $25.00 Paypal to the person who helps me solve whats wrong :-D

Originally Posted by nissanboy86

anyone ever hear of a ignition amplifier and switching module on a 1990 grandprix with a 3.1 in it?

I'm looking in Haynes manual page 12-27....

The problem i'am getting is im not getting fuel past the injectors... I'am assuming all my injectors did not go bad at the same time. The only 2 problems i could see it being is either the ECM or the ignition amplifier and switching module.

I have almost 50psi of pressure up to the injectors so its not fuel pump, filter, or regulator. (Regulator was just changed about 4k miles ago.)

What happens when this module goes bad anyone know?

id have it run on a scan tool. although to me it sounds like it could be a cam sensor our motors run 2 injectors at 1 time it goes 1-2, 3-4, 5-6 hence the mpfi- multiport fuel injection. and if i remember right the cam sensor tells the icm when to fire so id try that if that didnt work then its most likely the ecm ive never heard of the switching module so i cant tell you what that would cause or not.

like i said have it run on a scan tool only way to really tell what it is(or what it isnt) cuz ecms and icms get expensive.

Yes, crank and crank with nary a sputter. It happened to me and turned out to be a short circuited injector (it measured zero ohms) All it takes to drive you crazy is one shorted injector out of the 6. The ECM simply will not fire ANY injector if one is shorted despite the fact that the injectors are wired into two sets of three each and each set connects to its own ECM output.
A good injector measures 12 ohms therefore one set of three connected in parallel as they are will measure 4 ohms. In my case, one set measured zero ohms; the other, 4 ohms.
I just now saw your post of a while back and hope you got back in business long ago but I am posting this in the event some other poor soul runs into this vexing problem