TPI NO injector pulse signal
TPI NO injector pulse signal
Let me give you some background on my vehicle in question. Approx one year ago I put a TPI system on a new motor I build in a 96 Chevy Silverado. I used a well-constructed TPI wiring harness, and all the correct components, computer and EPROM. I am a Electrical Engineer and a reasonable mechanic, and I am very good with wiring and I know I have all the connections correct. I had the EPROM reprogrammed by a EFI connection due to my lack of hardware for doing so. He modified the computer to allow 24 LB/HR injectors, disable emissions, disable vats, ect.
So after installing, I had the motor running and it sounded GREAT, everything was fine! Approx 2 weeks later I pull the truck up to the garage, and shut it off, then try to start it back up, just cranks, no fuel (No Fuel Pulse Signal) when cranking the engine, but If I spray gas it starts up and runs, or If I ground the injectors (Connection C11 and C12 on the ECM) manually before starting like the ECM should do it will spray and start and runs fine. I know everything else is ok like fuel pressure, fuses, power, grounds, no open circuits, ect.
I installed a new distributor with module (tested), and replaced the 730 ECM with another used 730 ECM with the same PROM, still no dice, I have wasted 100s of dollars having GM mechanics look at it and telling me to replace distributor, ecm, ect, with no results. I checked the Fuel Injector resistances they are as follows
INJ #1 16.4 OHMS
INJ #2 16.4 OHMS
INJ #3 16.4 OHMS
INJ #4 16.4 OHMS
INJ #5 16.5 OHMS
INJ #6 16.3 OHMS
INJ #7 16.5 OHMS
INJ #8 16.5 OHMS
With the Fuel Injectors disconnected and check ECM connection C11 and C12 I get ground (0 V) at those connections, but with the Fuel Injectors connected I still get ground ( 0 V) but it seems like possibly it is too much current to drive the injectors (I am pulling that out of my A** I am not sure) because like I said above when I ground those pins, I get the injectors to spray. I don’t know what’s with that, its possible I am getting a incorrect reading I am not sure, That’s all I have any help would be appreciated,
Brett
So after installing, I had the motor running and it sounded GREAT, everything was fine! Approx 2 weeks later I pull the truck up to the garage, and shut it off, then try to start it back up, just cranks, no fuel (No Fuel Pulse Signal) when cranking the engine, but If I spray gas it starts up and runs, or If I ground the injectors (Connection C11 and C12 on the ECM) manually before starting like the ECM should do it will spray and start and runs fine. I know everything else is ok like fuel pressure, fuses, power, grounds, no open circuits, ect.
I installed a new distributor with module (tested), and replaced the 730 ECM with another used 730 ECM with the same PROM, still no dice, I have wasted 100s of dollars having GM mechanics look at it and telling me to replace distributor, ecm, ect, with no results. I checked the Fuel Injector resistances they are as follows
INJ #1 16.4 OHMS
INJ #2 16.4 OHMS
INJ #3 16.4 OHMS
INJ #4 16.4 OHMS
INJ #5 16.5 OHMS
INJ #6 16.3 OHMS
INJ #7 16.5 OHMS
INJ #8 16.5 OHMS
With the Fuel Injectors disconnected and check ECM connection C11 and C12 I get ground (0 V) at those connections, but with the Fuel Injectors connected I still get ground ( 0 V) but it seems like possibly it is too much current to drive the injectors (I am pulling that out of my A** I am not sure) because like I said above when I ground those pins, I get the injectors to spray. I don’t know what’s with that, its possible I am getting a incorrect reading I am not sure, That’s all I have any help would be appreciated,
Brett
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