Jed

As soon as I turn the ignition on the ecm1 fuse blows. I disconnected the fuel pump and it still blows. Injectors, pcm/vcm are on this fuse. The problem started when the fuel pump seemed to not be running. 99 Suburban 1500 5.7l 4x4 with 115k miles. Any ideas would be great!

Jed

Ok, so I've narrowed it down to the fuel injectors. When the injectors are plugged in the ecm1 fuse blows. When I unplugged the injectors ( 16 port plug) the fuse doesn't blow and the fuel pump runs normally. I tested each injector for resistance and they all seemed fine measuring 11.4 to 11.6 ohms. Can anyone please tell me how to test the power to the injectors? Also a wiring diagram for the injectors would be great!

Jed

Ok, Tested injector pulse with a noid light, all seem normal. Injectors all measure normal resistance. Ecm1 fuse blows the moment the ignition is turned on. Please help if you have any thoughts or ideas, thanks!

nauticstar87

Do you know if you have any codes?

Jed

Thanks for the response. I had two codes, none pending. One was was for low pressure in the fuel tank. That was because I had the sensor unplugged as we changed the fuel pump, plugged it back in, and the code is gone. The other was for secondary air injection, it was a past code. I believe that is for the pump the puts air in the exhaust gases to save the planet (sigh, whatever). Here is what happened. We towed it to dealer, for two hundred large they told us number five fuel injector is bad. For seven hundred grand total they will replace it, for thirteen hundred they'll replace the whole spider or at least all eight injectors. We refuse, we're towing home and I'll replace the injector. Can you verify for me that the number five injector is the one going to number five cylinder? (feels like a stupid question). And any adivice or warnings before I tear off the intake manifold cover and throttle body to replace the injector are more than welcome!

Jed

Ok, I replaced the whole spider, it looks like it was already updated to MFI, but there was a short on the number five injector right where the wires bend above where the injector fits into the intake manifold.