ScottEwine

I have my 1992 project put back together, replaced intake gaskets, optispark, did a tune up etc. The car has not run for 8+ years, I have drained the gas completely and put 5 gallons of hi-test in. I turned the car over long enough for the gas to get there and it did not start, turned it over a bit more and still nothing. Cracked the main fuel line to the fuel rail and nothing, so it seems I have a fuel pump issue. Any tips on troubleshooting that?

Scott

Solderhead

If it's been sitting that long, pump is probably shot. Do you hear a hum sound from the fuel tank area for about two seconds when you turn the key to the ON.position and before you crank it? The pump should come on to prime and pressurize the fuel system so adequate fuel is available at tnt injectors.

ScottEwine

I have not heard that hum, so I will assume the pump is shot.

Thanks,

Scott

billschroeder5842

Easy swap- 45 minutes. While you are in there consider taking apart your fuel sending unit and cleaning it. It only takes a minute or two and your fuel gauge will get a much improved signal.

ScottEwine

I have the assembly out and NAPA has the pump so I will dash over there and get one. Let me know if you have a link to the cleaning the sending unit.

Scott

Peku

Did you check the fuse?

ScottEwine

I have installed the pump and now I have fuel at the rail (I unhooked the supply line at the rail and there was pressure), but it does not start. It sounds like it is getting a bit of fuel in that it turns over a little more vigorously than before but that is the only change. What should I look at next? Could all of the injectors be gummed up enough that they will not function?

ScottEwine

I pulled the #2 plug wire and confirmed I have spark, so it seems it is not getting fuel. The car has not run for 8+ years, could all the injectors be gunked up? I did not clean them when I had the fuel rails off, not sure if that was even possible.

ScottEwine

So I guess it is possible that it is not a mechanical problem with the injectors, it could be that they are not getting the signal to open, never had a fuel injected corvette before, how do you troubleshoot electrical issues with fuel injection?

Thanks,

Scott

aklim

Only 2 ways to clean. Send it off for testing and know it is really cleaned and tested or dump some snake oil into the tank and pretend it is clean.

aklim

Get yourself a noid light. Beg, borrow or steal one from Autozone. They have a fuel injection testing light.

ScottEwine

That is on the agenda for tomorrow. I had one of the kids spray starter fluid in just now and it fired up so it seems it is an issue with fuel. Autozone is just 5 minutes away and I have borrowed tools from them in the past so they should be able to help me out here.

Scott

xrav22

Better change the fuel filter also.

ScottEwine

I did that and drained the old fuel before I put in new fuel. I have a friend that is bringing over a fuel injection test kit later today so I will be able to check it out in more detail.

Tom400CFI

It's a '92 (LT1) so this is easy. Unbolt the fuel rails and lift the fuel rails/injectors up/out of the manifold and support the rail/injectors assy above the intake. Crank the engine and watch the injectors. Are they all firing nice conical fuel shots? All the same? No? the ones that don't are bad. Change 'em.

I just went through this on an '89 that had sat for 5 years. of the 8 injectors, 3 worked. TPI is harder to do the above test on, than an LT1, but I was still able to do it:

ScottEwine

After I confirm that the injectors are getting a signal I may try this to confirm that the injectors are not working. Is this procedure safe? Can the injectors be cleaned or is buying new ones the only option?

Tom400CFI

It will take you longer to get the Noid light than to run my test. All the injectors on each side of the motor are wired in parallel...so if one fires, it's extremely likely that they all have power/ground. You can Key On and check for power at any/all of the injectors w/a Meter.



Not if you're smoking a cigi. Use a little common sense and it's safe enough. I've tested injectors this way many times; it's easy and conclusive.

ScottEwine

So if I find out it is the injectors and replace them I have seen where if they are not the exact same as stock I may need to reprogram the computer. The newest vette I have had before this one is a 1975 so computers are a new idea to me, how tough is it to reprogram?

ScottEwine

For example, I see several different sets of injectors at Summit that will work, ranging from 24 to 36 lbs/hr, what is the stock flow rate?

aklim

I'd go with FIC and get a reman set. He will know what you need.

https://fuelinjectorconnection.com/collections/gm-car-rebuilt-injectors/products/92-lt1