did I fry my computer


cobrah
11-05-2009, 07:09 PM
first off this is a van but I know they are basically the same setup as a silverado so I posted it here.

I am thinking the computer maybe junked out. Ok I bought a van around six months ago. It is a 1997 coversion van with the 5.7 tbi in it. When I bought it the fuel pump was bad so I temp. fixed it by hammering on the tank and it unstuck. It had been fine ever since. Last week I pull it in the garage to pull the junk 4l60e to have the clutches replaced, reinstall the trans and nothing, the van would crank over but the pump was not turning on, I try a new relay and nothing. I assume its a bad pump, I then install the new pump and the same thing just crank and no start. I also couldnt get the thing to really hit on ether either which is odd. I then check the old pump and it comes right on. So I keep trying to check grounds and make sure I didnt unhook anything on the trans job that would keep the pump from turning on and I cant find anything. Then today the battery was dead from all the cranking so I try to jump start it and cranked it over a few times and nothing then on the fourth try it started cranking a everything quit. NO more cranking, no interior lights, no dash lights, radio or anything. Keep in mind this was with jumper cables hooked up so there was plenty of power. I checked all of the relays I could think of and they are all great. Is there a main relay somewhere or what? Im thinking maybe the computer went out and maybe thats why it wouldnt turn the pump on then it crapped completely out when jumping it. Please help me.

j cAT
11-05-2009, 07:50 PM
first off this is a van but I know they are basically the same setup as a silverado so I posted it here.

I am thinking the computer maybe junked out. Ok I bought a van around six months ago. It is a 1997 coversion van with the 5.7 tbi in it. When I bought it the fuel pump was bad so I temp. fixed it by hammering on the tank and it unstuck. It had been fine ever since. Last week I pull it in the garage to pull the junk 4l60e to have the clutches replaced, reinstall the trans and nothing, the van would crank over but the pump was not turning on, I try a new relay and nothing. I assume its a bad pump, I then install the new pump and the same thing just crank and no start. I also couldnt get the thing to really hit on ether either which is odd. I then check the old pump and it comes right on. So I keep trying to check grounds and make sure I didnt unhook anything on the trans job that would keep the pump from turning on and I cant find anything. Then today the battery was dead from all the cranking so I try to jump start it and cranked it over a few times and nothing then on the fourth try it started cranking a everything quit. NO more cranking, no interior lights, no dash lights, radio or anything. Keep in mind this was with jumper cables hooked up so there was plenty of power. I checked all of the relays I could think of and they are all great. Is there a main relay somewhere or what? Im thinking maybe the computer went out and maybe thats why it wouldnt turn the pump on then it crapped completely out when jumping it. Please help me.


with a meter measure the voltage at the battery when cranking after you charged the battery for 8hrs with a battery charger...monitor the charging current..then attempt to start ..if no cranking with a jumper wire short out the solenoid to see if the starter starts..if not then the starter was cooked...also check the fuseable wire links in the starter area ...

jumping a dead battery is a very good way to destroy the computer...best recharge the battery over a few hours rather than ram 60amps into it in 5 minutes...

10 sec. crank,,,then wait 3 min...this will not damage the starter..

no start what is the fuel pressure ? squirts pretty good is not troubleshooting helpful..

also being a van is not the same... check all fuses with a meter

kahjdh
11-08-2009, 01:30 AM
I know there is alot of probs with the ecm's rotting in these due to their location. Also the fuel pump connectors on top of the tank are prone failure and napa sells a replacement pigtail. Check to see if you have power and ground from the main harness while somebody is cranking.

cobrah
11-11-2009, 09:09 PM
I unhooked the battery and got everything working except the fuel pump. There is not any power at the fuel pump plug. There are four wires black with white purple with white drk blue and grey. I am lost on what to try and why this started with a trans swap

j cAT
11-12-2009, 04:31 PM
I unhooked the battery and got everything working except the fuel pump. There is not any power at the fuel pump plug. There are four wires black with white purple with white drk blue and grey. I am lost on what to try and why this started with a trans swap

you did not mention fuses..how did you get the other componets to power up?

at the fuel pump relay do you have power to the switching contacts ?

Add your comment to this topic!