Testing fuel pump relay on a 90 corvette

Yea , those crossfire injection vettes can be a bear sometimes . I had dealings with them 84-85 - 86 working as a tech at a chevy dealer . Don't remember much about them , haven't heard anything about them for long time .

How's the fuel pressure ? Have you put a fuel gauge on it ? I would imagine you don't have a Tech 1 scan tool ? What's the map sensor voltage at idle ?

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The only part that would come to mind after all of this would be the fuel pump relay. This is located on the fire wall on the drivers side of the car. When that goes bad it does not allow for adequate fuel to cycle through.The other thing would be timing. You need fuel air and spark for the vehicle to fire. After all the test and after replacing the fuel pump relay. I would do a compression and a leak down test. Are you sure that the timing did not jump a gear? You can also look and test the IAC (Idle Air Control) or the MAF (Mass Air Flow Sensor). Also do a test to check fuel pressure. The last Corvette that I worked on personally that had this issue it turned out to be the Fuel Pump Relay. Good luck let me know if you have any further questions.

When was the last tune up? What was changed? Coils are notorious for a non running condition. Dead cell in battery or loose battery connections can make it stall. Bad alternator also. Bad fuel filter or fuel pump. Any of these are places to start checking.

CHECK FUEL PUMP RELAY. TRY STARTING FLUID .IF THAT DONT MAKE IT FIRE YOU HAVE NO SPARK

If your vehicle is factory should have electronic multiport fuel injection, and would have a fuel pump located inside the gas tank with the sending unit to the fuel gauge. also check fuses and relays first before removing tank. and ensure that you have spark before checking fuel, unless you know that spark is good. oh i this is of course if the vehicle is cranking at lease, if not start with the starting and ignition circuits. hope this will help.

It sounds to me as though you have a clogged or malfunctioning fuel pump. Depending on the engine in your car, and whether or not the engine has a carb or fuel injection system.

In most of the early 90's corvette's, there should still be a fuel filter on the fuel injection throttle body (it looks like a carb), and a fuel filter under the car on the fuel lines. I believe you'll want to check the passenger side, but follow the fuel lines to find the filter. You might only have one under the car, so don't be alarmed if you don't find a small one on the throttle body.

Try changing your fuel filters first, as this is an inexpensive way to make sure your vette is in optimum condition before you do anything else.

If fuel filter replacement doesn't work, you will want to have your fuel pump tested. The only way to DIY, is to remove the fuel pump from the lower drivers side of the engine and to blow in the "in" side with a little water and see if it puts out the fluid. Even at that it could still be bad, so if you pull the pump, plan on replacing it.

The only other realistic option is that your fuel injectors are dirty or the gaskets are bad and it is time for an injector overhaul. This is not to hard to DIY, but does take patience and attention. You can also try running some fuel injection cleaner through your engine before trying anything else to see if it helps.

Some unlikely options are that your smog pump is clogged, your catalytic converter might be bad, you EGR valve or Purge Valve is clogged, your timing is off and you need to check the spark system, or that you could have low compression.

is it fuel injected? you might have a faulty sensor it sounds like a vapor lock, also you fuel injectors might be dirty or bad also check fuel pump pressure or a cloged fuel filter, or it is putting to much gas if your vette has a carb.

I had the same problem. Turns out,( and I didn't believe it when I was told) but, my problem turned out to be cheap (inferiour) plugs and wired. I was reccomended to use NKG plugs and Borg-Warner wires.

I am looking at alldata , the schematics for the fuel system. I see a fuse in the fuse block(10 amp) that comes from the fuel pump relay to the pump. I see a fuseable link (link H)that goes through a oil pressure sending unit. I would get a test light and test the oil pressure sending unit, the inline fuseable link and the relay. If still no power check the connection at the pump and then work backwards testing the harness.

is it a security light that comes on? if so you may have a problem with the ign system. can you hear the fuel pump come on when the key is turned on?