Question about IROC Fuel Pump
04-20-2015, 11:25 AM
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Car: 1987 IROC Z
Engine: LB9
Transmission: 700-4R
Question about IROC Fuel Pump
Hi Guys
Having issues with my IROC LB9 1987 not starting.
I originally thought this was a ignition issue.. the usual IGNITION MODULE problem when it stalled out on the side of the road. Changed the module with a backup on the side of the road and the IROC fired right up and was good for a few days. This motivated me to take care (tune up) things that appeared to be slipping.... replaced some "arc'ing" ignition wires with a new set (warranty) and even bought a new coil. After doing these I drove around and all appeared happy for a day...then the next morning no start. I replaced the distributor with a backup (that was working when I took it off 2 years ago) and installed a backup (NEW) module and the same no start. I was very careful to position the new distributor in the same exact position as the one that was removed.
1.) Diagnostic codes- None
2.) tried starting it with a backup MAF and with it unplugged- no sart
3.) checked all fuses, including the one by the battery for the ECM and fuel pump
4.) when I turn on the ignition the fuel pump primes every time.
5.) when I crank it appears to have spark (screwdriver test)
QUESTION: I don't have a fuel pressure tester... Is it possible that even with the pump priming.. that it isn't putting enough PSI to the injectors? The primal symptoms when I first started seeing this weird stuff was at times (not every time) when I first start it up it appeared to have lack of power and/or a miss as if a delay in shifting. The only other thing I haven't verified is the Electronic Spark Control thing that is near the relays...
I am going to manually set TDC with cylinder #1 and see if somehow it's a timing issue.. but then again I was very careful when replacing the distributor with the backup to put it in the exact position as the one I replaced....
Having issues with my IROC LB9 1987 not starting.
I originally thought this was a ignition issue.. the usual IGNITION MODULE problem when it stalled out on the side of the road. Changed the module with a backup on the side of the road and the IROC fired right up and was good for a few days. This motivated me to take care (tune up) things that appeared to be slipping.... replaced some "arc'ing" ignition wires with a new set (warranty) and even bought a new coil. After doing these I drove around and all appeared happy for a day...then the next morning no start. I replaced the distributor with a backup (that was working when I took it off 2 years ago) and installed a backup (NEW) module and the same no start. I was very careful to position the new distributor in the same exact position as the one that was removed.
1.) Diagnostic codes- None
2.) tried starting it with a backup MAF and with it unplugged- no sart
3.) checked all fuses, including the one by the battery for the ECM and fuel pump
4.) when I turn on the ignition the fuel pump primes every time.
5.) when I crank it appears to have spark (screwdriver test)
QUESTION: I don't have a fuel pressure tester... Is it possible that even with the pump priming.. that it isn't putting enough PSI to the injectors? The primal symptoms when I first started seeing this weird stuff was at times (not every time) when I first start it up it appeared to have lack of power and/or a miss as if a delay in shifting. The only other thing I haven't verified is the Electronic Spark Control thing that is near the relays...
I am going to manually set TDC with cylinder #1 and see if somehow it's a timing issue.. but then again I was very careful when replacing the distributor with the backup to put it in the exact position as the one I replaced....
04-21-2015, 07:28 PM
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Re: Question about IROC Fuel Pump
Try something even eeeeeezier:
Add some fuel to the intake some other way. (attach a hose to the PCV fitting and pour some fuel down it for example)
One of 2 things will happen:
Either it will start and try to run for acoupla seconds, or it won't.
If it does, you have a fuel problem.
If it doesn't you have an ignition problem.
Add some fuel to the intake some other way. (attach a hose to the PCV fitting and pour some fuel down it for example)
One of 2 things will happen:
Either it will start and try to run for acoupla seconds, or it won't.
If it does, you have a fuel problem.
If it doesn't you have an ignition problem.
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