Not a clue.
senoggle
10-30-2004, 05:19 PM
Have a 96 Sierra vortex truck. The injectors will not fire, if I put a little gas into the air intake it will run till the gas is gone.
New fuel pump and relay.
New fuel presure regulator.
New Ignition module.
New computer.
New crank case sensor, (old only putting out 2.2 VAC)
If you have any ideas please let me know, thanks.
New fuel pump and relay.
New fuel presure regulator.
New Ignition module.
New computer.
New crank case sensor, (old only putting out 2.2 VAC)
If you have any ideas please let me know, thanks.
GMMerlin
10-30-2004, 07:59 PM
1 of 2 things could be going on...
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
senoggle
10-31-2004, 09:09 AM
1 of 2 things could be going on...
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
The injectors all have 12 volt source and the switching lines from the computer all ohm out good, but are not switching on and off from the computer. I checked for switching at the injectors and the computer and no go. I don't understand "stuck injectors", cause I can switch them on and off manually. Something is telling the computer not to fire the injectors. This is my neighbors truck and I am trying to help out. Do you know what could tell the computer to not fire the injectors. The fuel system has been all replaced from the fuel pump to the injectors.
He ordered a computer and they sent him a replacement without the chip in the computer and was told to use the chip in the old computer but he did not take it out of the old one before he sent it in and so bought one from a dealer. Does any of this stuff have to be reprogramed to work...?
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
The injectors all have 12 volt source and the switching lines from the computer all ohm out good, but are not switching on and off from the computer. I checked for switching at the injectors and the computer and no go. I don't understand "stuck injectors", cause I can switch them on and off manually. Something is telling the computer not to fire the injectors. This is my neighbors truck and I am trying to help out. Do you know what could tell the computer to not fire the injectors. The fuel system has been all replaced from the fuel pump to the injectors.
He ordered a computer and they sent him a replacement without the chip in the computer and was told to use the chip in the old computer but he did not take it out of the old one before he sent it in and so bought one from a dealer. Does any of this stuff have to be reprogramed to work...?
senoggle
10-31-2004, 09:15 AM
The injectors all have 12 volt source and the switching lines from the computer all ohm out good, but are not switching on and off from the computer. I checked for switching at the injectors and the computer and no go. I don't understand "stuck injectors", cause I can switch them on and off manually. Something is telling the computer not to fire the injectors. This is my neighbors truck and I am trying to help out. Do you know what could tell the computer to not fire the injectors. The fuel system has been all replaced from the fuel pump to the injectors.
He ordered a computer and they sent him a replacement without the chip in the computer and was told to use the chip in the old computer but he did not take it out of the old one before he sent it in and so bought one from a dealer. Does any of this stuff have to be reprogramed to work...?
One other thing, the crankcase sensor only put out 2.2 VAC with 13 Volts source. I get 2.2 in the truck or on the bench. The book says 5volts and I expected 4.7 more or less. Is this normal. And thanks very much.
He ordered a computer and they sent him a replacement without the chip in the computer and was told to use the chip in the old computer but he did not take it out of the old one before he sent it in and so bought one from a dealer. Does any of this stuff have to be reprogramed to work...?
One other thing, the crankcase sensor only put out 2.2 VAC with 13 Volts source. I get 2.2 in the truck or on the bench. The book says 5volts and I expected 4.7 more or less. Is this normal. And thanks very much.
senoggle
10-31-2004, 09:24 AM
1 of 2 things could be going on...
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
If the fuel pressure is not high enough will this tell the computer not to fire the injectors...? The fuel system and pressure regulator was replaced before I got on the project. Thanks again.
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
If the fuel pressure is not high enough will this tell the computer not to fire the injectors...? The fuel system and pressure regulator was replaced before I got on the project. Thanks again.
sammy2
01-17-2005, 02:32 AM
This is new to me and I am gleaning useful info from posts....my veh is 87 ply voy, an injector was leaking and I picked up fuel rail with inj from salvage yard....though I disconnected ....and removed plenum, someone else repl the injector[s] not just the leaking one. Veh will start fine and not run. I used computer to test and get a code 26...which told me that there was high resistance in inj[s] 1, 2 or 3. I've removed plenum and am not certain what to do next. I have never tested injectors with ohm meter and really have not much clue. Help with this would be much appreciated....my window for time is small. Good chance that I will work thru much of night as I have to work tomorrow...I need help, Thank you.
1 of 2 things could be going on...
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
1 of 2 things could be going on...
First the injectors are not being powered electrically...remove the injector connector on the top of the intake and using a test light jumper between the terminals for 1 injector while spinning over the engine if the light flashes then the injectors are being controled.
Next, if you have fuel pressure (60-65 psi) and the injectors are being controlled then you have a set of stuck injectors.....GM dealers have a tool and a procedure for unsticking the injectors using high pressure nitrogen...if that doesnt work then there is a replacement injector unit for your vehicle
There is a GM TSB for this..I don't remember the number
sammy2
01-17-2005, 02:34 AM
Which is injector 1?
This is new to me and I am gleaning useful info from posts....my veh is 87 ply voy, an injector was leaking and I picked up fuel rail with inj from salvage yard....though I disconnected ....and removed plenum, someone else repl the injector[s] not just the leaking one. Veh will start fine and not run. I used computer to test and get a code 26...which told me that there was high resistance in inj[s] 1, 2 or 3. I've removed plenum and am not certain what to do next. I have never tested injectors with ohm meter and really have not much clue. Help with this would be much appreciated....my window for time is small. Good chance that I will work thru much of night as I have to work tomorrow...I need help, Thank you.
This is new to me and I am gleaning useful info from posts....my veh is 87 ply voy, an injector was leaking and I picked up fuel rail with inj from salvage yard....though I disconnected ....and removed plenum, someone else repl the injector[s] not just the leaking one. Veh will start fine and not run. I used computer to test and get a code 26...which told me that there was high resistance in inj[s] 1, 2 or 3. I've removed plenum and am not certain what to do next. I have never tested injectors with ohm meter and really have not much clue. Help with this would be much appreciated....my window for time is small. Good chance that I will work thru much of night as I have to work tomorrow...I need help, Thank you.
sammy2
01-17-2005, 03:23 AM
Okay, I removed metal clip & connector from injector, not knowing which to test the injector or connector I used ohm meter on both....most had a reading of .015-.017 but one connector and one injector [ i believe it was] had a reading of .004. I was told to watch for a spike. The odd reads were : one in 3rd position closest to firewall and the other was center and to front of veh. I do not know where to go from here.
sammy2
01-18-2005, 02:07 AM
Test done following instruction from a post. Results:
inj 1 .015
inj 2 .015
inj 3 .015
inj 4 .015
inj 5 .004
inj 6 .015
injector 5 is the one that was replaced because fuel was not dripping but running out. What would next step be. My Chilton's manual has not been helpful in dealing with this matter.
inj 1 .015
inj 2 .015
inj 3 .015
inj 4 .015
inj 5 .004
inj 6 .015
injector 5 is the one that was replaced because fuel was not dripping but running out. What would next step be. My Chilton's manual has not been helpful in dealing with this matter.
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