Tech Support Forum - View Single Post - 95 Chev PU / Check Engine light In-Operable & No fuel

UsedCarManTN · 05-12-2009, 11:26 PM

Any help would be greatly appreciated!
We recently did an engine change in this truck but, I'm not sure if this problem existed before then. Let me begin by saying that this is a pretty nice 1995 Chevrolet Silverado Ex-Cab / 5.7 / 2 Wheel drive / 5 Spd. and the engine swap was prety much bolt for bolt. We are still using everything factory (tbi fuel injection and stock everything else) and when we got it, it had a couple of valves bent from an over rev because the previous owner tried to siphen some gas out of another vehicle back last fall when gas prices were so high. Needless to say he ended up with a tank full of muck and his response was to rev it up as high as it would go to try to "blow" out whatever was causing it to run bad (not a real genius).
So, after emptying the fuel tank of everything, changing the fuel pump, and changing the engine, when we went to fire it up it has no power to the fuel pump but, it will run when we poured a little gas down the throttle body. At first it blew the ECM-B fuse every time we put one in it and after checking every wire we could for being pinched in the bell housing or something we loaded it on a trailer to take it somewhere else where we had more equipment to deal with it, then it wasn't blowing fuses but wouldn't do anything. That's when we found out the MIL light on the dash wasn't working.
Now, we did some homework and after checking the relay, the continuity of all the wires leading to & from the tank/pump/relay/ and fuse panel (ECM-B) and tirelessly checking every ground we could find, we have come to the conclusion that somehow the ECU is dead. When we turn the key on, there is no "Service Engine Soon" (MIL) light nor a CHECK GUAGES light but, all the rest of the idiot lights come on. We have another 95 chev truck here to try some part swaps but it is a 4WD Automatic and the ECMs are totally different but, when we turn the key to the on position without starting it, both these lights and the other normal lights come on. So, we feel pretty sure we're on the right track. We have no blown fuses and have even taken the ECM out and removed it from it's case and with a thorough inspection visually can find nothing wrong with it.
I know that things can be wrong with electronics without looking bad but, without ALLDATA (which I sorely miss) I am kinda in the dark now as to where to turn next without trying to order some expensive computer from the parts house that if it does not fix it, I can't take back. Any suggestions anyone? Usually, I'm the "go to" guy that everyone asks these kinds of questions to but, this time I'm stuck.
Thanks

05-12-2009, 11:26 PM	#1 (permalink)
UsedCarManTN Registered User Join Date: May 2009 Posts: 5 OS: Vista	95 Chev PU / Check Engine light In-Operable & No fuel Any help would be greatly appreciated! We recently did an engine change in this truck but, I'm not sure if this problem existed before then. Let me begin by saying that this is a pretty nice 1995 Chevrolet Silverado Ex-Cab / 5.7 / 2 Wheel drive / 5 Spd. and the engine swap was prety much bolt for bolt. We are still using everything factory (tbi fuel injection and stock everything else) and when we got it, it had a couple of valves bent from an over rev because the previous owner tried to siphen some gas out of another vehicle back last fall when gas prices were so high. Needless to say he ended up with a tank full of muck and his response was to rev it up as high as it would go to try to "blow" out whatever was causing it to run bad (not a real genius). So, after emptying the fuel tank of everything, changing the fuel pump, and changing the engine, when we went to fire it up it has no power to the fuel pump but, it will run when we poured a little gas down the throttle body. At first it blew the ECM-B fuse every time we put one in it and after checking every wire we could for being pinched in the bell housing or something we loaded it on a trailer to take it somewhere else where we had more equipment to deal with it, then it wasn't blowing fuses but wouldn't do anything. That's when we found out the MIL light on the dash wasn't working. Now, we did some homework and after checking the relay, the continuity of all the wires leading to & from the tank/pump/relay/ and fuse panel (ECM-B) and tirelessly checking every ground we could find, we have come to the conclusion that somehow the ECU is dead. When we turn the key on, there is no "Service Engine Soon" (MIL) light nor a CHECK GUAGES light but, all the rest of the idiot lights come on. We have another 95 chev truck here to try some part swaps but it is a 4WD Automatic and the ECMs are totally different but, when we turn the key to the on position without starting it, both these lights and the other normal lights come on. So, we feel pretty sure we're on the right track. We have no blown fuses and have even taken the ECM out and removed it from it's case and with a thorough inspection visually can find nothing wrong with it. I know that things can be wrong with electronics without looking bad but, without ALLDATA (which I sorely miss) I am kinda in the dark now as to where to turn next without trying to order some expensive computer from the parts house that if it does not fix it, I can't take back. Any suggestions anyone? Usually, I'm the "go to" guy that everyone asks these kinds of questions to but, this time I'm stuck. Thanks