no power/pulse to injectors. Please Help
11-14-2017, 10:53 PM
#21
Melting Slicks
11-14-2017, 11:44 PM
#22
I would back probe the TPS and either verify or adjust for the .54 voltage signal at the idle position. According to the Blue sheet an appreciably Higher voltage is determined by the ECM as an engine flood condition and will turn Off the injectors.
Which FSM do you have; the factory manual or a cheaper version Haynes type of manual.
Which FSM do you have; the factory manual or a cheaper version Haynes type of manual.
11-14-2017, 11:48 PM
#23
Team Owner
I’ll check the tps when I get some time and let you how it goes. When I came to the fsm I just googled it I read how things work in order step by step but It’s not telling me what’s wrong with it. Everything is leading me to all the expensive scan tools and probes so I’m waiting on money to roll in before I can actually get to the bottom of it
11-15-2017, 02:47 AM
#24
Melting Slicks
I have no power/ pulse to my injectors. it all started with a head gasket leak. I tore everything off all the way down to the block to make sure to replace all top end gaskets.
In the process i decided to change the distributor, coil, plugs and wires, distributor modular, oil sending unit, fuel pump, fuel filter, tps sensor, ecm, fuel pump relay, radiator and i know there are other things that are not coming to mind but iv pretty much rebuilt this whole car.
iv got everything working all the way up to the injectors. The car wants to start with starter fluid. my fuel pressure holds at 42. i used a noid light to test the injector harness pulse and none of them work besides the cold start injector. Please help.
In the process i decided to change the distributor, coil, plugs and wires, distributor modular, oil sending unit, fuel pump, fuel filter, tps sensor, ecm, fuel pump relay, radiator and i know there are other things that are not coming to mind but iv pretty much rebuilt this whole car.
iv got everything working all the way up to the injectors. The car wants to start with starter fluid. my fuel pressure holds at 42. i used a noid light to test the injector harness pulse and none of them work besides the cold start injector. Please help.
The Inj 1 and Inj 2 fuses supply the power (pink/black wires at injector harness) the ECM grounds the injectors light Blue wire for Cylinders 1, 3, 5,7 and light green for Cyl 2,4,6,8.
If you have no power to injectors while someone cranks the engine over via ignition switch check the switch at lower part of column.
A noid light or multimeter should flash or show 12 volt pulses (across the two injector connector terminals) while the engine is being cranked over or running.
They batch fire, all right bank then all left bank
So either no power via inj 1 or inj 2 fuses (via ignition switch) which is supplied by fusable links from battery. or ECM ground.
Confirm the light green and light blue wires ground via the ECM.
Good luck
11-15-2017, 11:47 AM
#25
I would back probe the TPS and either verify or adjust for the .54 voltage signal at the idle position. According to the Blue sheet an appreciably Higher voltage is determined by the ECM as an engine flood condition and will turn Off the injectors.
Which FSM do you have; the factory manual or a cheaper version Haynes type of manual.
Which FSM do you have; the factory manual or a cheaper version Haynes type of manual.
11-15-2017, 11:54 AM
#26
Team Owner
11-15-2017, 12:02 PM
#27
Hi What year C4?
The Inj 1 and Inj 2 fuses supply the power (pink/black wires at injector harness) the ECM grounds the injectors light Blue wire for Cylinders 1, 3, 5,7 and light green for Cyl 2,4,6,8.
If you have no power to injectors while someone cranks the engine over via ignition switch check the switch at lower part of column.
A noid light or multimeter should flash or show 12 volt pulses (across the two injector connector terminals) while the engine is being cranked over or running.
They batch fire, all right bank then all left bank
So either no power via inj 1 or inj 2 fuses (via ignition switch) which is supplied by fusable links from battery. or ECM ground.
Confirm the light green and light blue wires ground via the ECM.
Good luck
The Inj 1 and Inj 2 fuses supply the power (pink/black wires at injector harness) the ECM grounds the injectors light Blue wire for Cylinders 1, 3, 5,7 and light green for Cyl 2,4,6,8.
If you have no power to injectors while someone cranks the engine over via ignition switch check the switch at lower part of column.
A noid light or multimeter should flash or show 12 volt pulses (across the two injector connector terminals) while the engine is being cranked over or running.
They batch fire, all right bank then all left bank
So either no power via inj 1 or inj 2 fuses (via ignition switch) which is supplied by fusable links from battery. or ECM ground.
Confirm the light green and light blue wires ground via the ECM.
Good luck
11-15-2017, 01:34 PM
#30
Team Owner
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nmay (11-15-2017)
11-15-2017, 02:24 PM
#31
11-15-2017, 05:06 PM
#32
Team Owner
11-15-2017, 07:50 PM
#34
Team Owner
IIRC, the TPS is adjustable. http://www.enduringautomotive.com/tps/
IDK. I'd use my scanner but you can try unplugging the battery or going to Autozone. Supposedly they tell you to unplug the battery and turn on the light or wait for 20 mins. Never verified that personally so IDK.
IDK. I'd use my scanner but you can try unplugging the battery or going to Autozone. Supposedly they tell you to unplug the battery and turn on the light or wait for 20 mins. Never verified that personally so IDK.
11-15-2017, 09:58 PM
#35
Melting Slicks
Here is the Code interrogation instruction;
http://www.corvettephotographs.com/c4vettes/codes.htm
To Clear the codes on an 87 you can simply remove the Battery negative cable for a few seconds, and reattach.
http://www.corvettephotographs.com/c4vettes/codes.htm
To Clear the codes on an 87 you can simply remove the Battery negative cable for a few seconds, and reattach.
11-15-2017, 11:39 PM
#36
Team Owner
Here is the Code interrogation instruction;
http://www.corvettephotographs.com/c4vettes/codes.htm
To Clear the codes on an 87 you can simply remove the Battery negative cable for a few seconds, and reattach.
http://www.corvettephotographs.com/c4vettes/codes.htm
To Clear the codes on an 87 you can simply remove the Battery negative cable for a few seconds, and reattach.
11-16-2017, 03:43 AM
#37
Melting Slicks
Yep, there should be a main ECM fuse, just trying to keep things simple..
11-16-2017, 08:59 AM
#38
Melting Slicks
I have no power/ pulse to my injectors. it all started with a head gasket leak. I tore everything off all the way down to the block to make sure to replace all top end gaskets.
In the process i decided to change the distributor, coil, plugs and wires, distributor modular, oil sending unit, fuel pump, fuel filter, tps sensor, ecm, fuel pump relay, radiator and i know there are other things that are not coming to mind but iv pretty much rebuilt this whole car.
iv got everything working all the way up to the injectors. The car wants to start with starter fluid. my fuel pressure holds at 42. i used a noid light to test the injector harness pulse and none of them work besides the cold start injector. Please help.
In the process i decided to change the distributor, coil, plugs and wires, distributor modular, oil sending unit, fuel pump, fuel filter, tps sensor, ecm, fuel pump relay, radiator and i know there are other things that are not coming to mind but iv pretty much rebuilt this whole car.
iv got everything working all the way up to the injectors. The car wants to start with starter fluid. my fuel pressure holds at 42. i used a noid light to test the injector harness pulse and none of them work besides the cold start injector. Please help.
Lot's of people helping you here ... we should be able to help figure this out. Also the ECM for an 86 has the driver transistors for the injectors. It is your cars brain. If it will not display 12's then there is something seriously wrong.
Last edited by 3D-Aircrew; 11-16-2017 at 09:01 AM. Reason: added
11-16-2017, 10:15 AM
#39
Team Owner
11-16-2017, 12:27 PM
#40
Burning Brakes
Member Since: Oct 2017
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iirc it's a backup for the fuel pump relay.
that's what I thought about the injectors being fed 12v from the fuse panel, but chevythunder.com says otherwise.
Good point about the ignition switch. Nmay, do you hear the fuel pump prime when you turn the key on?
You have to check for injector power at the injector plug, not just at the fuse panel.
It should show 12s anyway whether there are other codes or not. 12 just means the engine isn't running.
Hi What year C4?
The Inj 1 and Inj 2 fuses supply the power (pink/black wires at injector harness) the ECM grounds the injectors light Blue wire for Cylinders 1, 3, 5,7 and light green for Cyl 2,4,6,8.
A noid light or multimeter should flash or show 12 volt pulses (across the two injector connector terminals) while the engine is being cranked over or running.
They batch fire, all right bank then all left bank
So either no power via inj 1 or inj 2 fuses (via ignition switch) which is supplied by fusable links from battery. or ECM ground.
Confirm the light green and light blue wires ground via the ECM.
Good luck
The Inj 1 and Inj 2 fuses supply the power (pink/black wires at injector harness) the ECM grounds the injectors light Blue wire for Cylinders 1, 3, 5,7 and light green for Cyl 2,4,6,8.
A noid light or multimeter should flash or show 12 volt pulses (across the two injector connector terminals) while the engine is being cranked over or running.
They batch fire, all right bank then all left bank
So either no power via inj 1 or inj 2 fuses (via ignition switch) which is supplied by fusable links from battery. or ECM ground.
Confirm the light green and light blue wires ground via the ECM.
Good luck
Good point about the ignition switch. Nmay, do you hear the fuel pump prime when you turn the key on?
My c4 is a spilt year between 86 and 87 i think. my title says 86 but the vin says 87 and the vin on the title matches the car. i have power in the injector spots on the fuse panel. i havent checked the ecm ground yet. not sure how to do it. someone on this forum told me to check for volts at the tps and i still havent yet. you said check the ignition switch for power and its toward the lower end of the steering problem?
Have you used the paperclip method to pull your codes? If you did there should be only 12's unless something is wrong.
Lot's of people helping you here ... we should be able to help figure this out. Also the ECM for an 86 has the driver transistors for the injectors. It is your cars brain. If it will not display 12's then there is something seriously wrong.
Lot's of people helping you here ... we should be able to help figure this out. Also the ECM for an 86 has the driver transistors for the injectors. It is your cars brain. If it will not display 12's then there is something seriously wrong.