no injector pulse
Thread Starter
Instructor
Joined: Sep 2004
Posts: 208
Likes: 1
From: Lawrenceville GA
no injector pulse
I don't know how to repost my last post of about 2/3 but I was at a no crank point. I have replaced the ign sw. verified the battery and all fuses (twice over). I jumpered the purple wire to the yellow wire on the start relay and it turns over like brand new just no injector pulse so no run. I was pointed at VATS or central control module but I don't know anything about either. I did try a spare ECM. The injectors all light up but no pulse. Tried a separate key also. ANY IDEAS? I want my car back!
Thanks guys!! and gals
Thanks guys!! and gals
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
I don't know how to repost my last post of about 2/3 but I was at a no crank point. I have replaced the ign sw. verified the battery and all fuses (twice over). I jumpered the purple wire to the yellow wire on the start relay and it turns over like brand new just no injector pulse so no run. I was pointed at VATS or central control module but I don't know anything about either. I did try a spare ECM. The injectors all light up but no pulse. Tried a separate key also. ANY IDEAS? I want my car back!
Thanks guys!! and gals
Thanks guys!! and gals
are you saying you have a steady light? you are assuming no injector "pulse" which is what the test will tell you.
Thread Starter
Instructor
Joined: Sep 2004
Posts: 208
Likes: 1
From: Lawrenceville GA
I have good spark just no fuel. Fuel pump can be heard. Following the FSM it would appear VATS has failed. Without jumpering the starter I have no crank and no injector pulse, just steady light. Found an earlier post as to bypassing VATS. Ordered a kit yesterday off Ebay. Hope it works. I've yet to find a CCM anywhere.
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
I have good spark just no fuel. Fuel pump can be heard. Following the FSM it would appear VATS has failed. Without jumpering the starter I have no crank and no injector pulse, just steady light. Found an earlier post as to bypassing VATS. Ordered a kit yesterday off Ebay. Hope it works. I've yet to find a CCM anywhere.
no idea what year you have. if you have the FSM you can pull codes from the ccm on the '91, also the ecm of course. if a key does not read it should show a ccm code, not sure what they are but I have pulled all of them before.
ccm sends inputs to ecm once key resistance is read. ignition switch is directly connected to ccm.
only time I had issues was with key not reading. finally bypassed the key with a harness from Echler's.
but, steady light is not VATs issue best I recall.
Last edited by joe paco; Mar 10, 2014 at 05:56 PM. Reason: clarity ***
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I was wondering too, but from his avatar I would guess it's a '93. Putting the year in the original post is generally a good idea...
I would verify fuel pressure at the fuel rail. A gauge is a LOT more accurate than "I think...".
The injectors don't pulse unless they get reference pulses from the opti-spark (or distributor on earlier years). The ECM uses the reference pulses to synchronize the injector pulses to the rotation of the engine. The engine must be cranking or running for the opti-spark to produce reference pulses.
I would verify fuel pressure at the fuel rail. A gauge is a LOT more accurate than "I think...".
The injectors don't pulse unless they get reference pulses from the opti-spark (or distributor on earlier years). The ECM uses the reference pulses to synchronize the injector pulses to the rotation of the engine. The engine must be cranking or running for the opti-spark to produce reference pulses.
