Ive got a 1990 vette, and all my experience in cars is with a 73 c10, so I'm pretty overwhelmed with the complicatedness of a corvette.

If anyone could tell me where to start, I would be grateful.

Symptoms:

When vette starts, it sounds HORRIBLE, bogged down, when you press the gas it tries to rev up and falls on it's face. Seems like a fuel system problem to me.

Fuel pump is new, don't know much else.

Oh and when it did start a few months ago, it would run until it got warm, then if you turned it off, it wouldn't start again for a few hours.

Throw me some suggestions of what I can start checking, to try to figure out what's going on!

 

Falling flat on its face when revved sounds like cat converter going south.
Hard start when warm...???? Could be a few things...
Check fuel pressure and check for spark when cranking.
Probably not a bad idea to replace fuel filter at this time.

 

Brand new magnaflow cat, definitely not the problem. I had it in a shop and they said it had fuel pressure.

It's got spark because it will start if I give it some gas, but I have to keep gassing it to keep it running.

I'm thinking fuel injectors, will ohm test them tomorrow.

 

Tested the fuel injectors, all are 16-17, except for 2, which are 12 and 0.

Is the next step replacing just those two injectors?

 

Call John at FIC. He will make you a deal. See the sticky on injectors.

 

Replace all 8 !!!!!!!!!!!!!!!!

As suggested, call Jon

 

Fuel filter been replaced?

 

No, but I checked fuel pressure, off and running, and it's staying above 40.

I'll call Jon, thanks

 

Holy crap - in the last 30 or so years, this is your first car with electronic fuel injection???

How much fuel it gets is a function of Coolant Temp (and that's true for whatever Toyota you might have in your future - assuming it has an internal combustion engine) and the ECM sends 5 volts to a thermistor which is a device that loses resistance as it warms up so as more of that reference voltage reaches ground the higher the voltage drop which is used to calculate temperature which then determines how often the injectors are cycled on/off. If the temperature isn't right, fueling isn't right, and it'll either get too much or too little meaning it doesn't run right. You check what it is with a Scanner and after the engine has sat overnight, it should be the same or very close to outside air temp. Then start the car and there should be a linear rise until the thermostat opens, then a small decrease before it increases to whatever the threshold is for main fan operation. I'd start there first. It replaces the choke which you might suspect if your '73 whatever had a similar problem.

 

You need some basic test tools before ANY of this makes sense...
GM Factory service manual (before anything else) (e-bay used $75 two book set)
fuel pressure gauge
noid lite
spark tester
paper clip

eventually....
Vac tester
compression tester

Your choking and gagging when you apply throttle could be a cat pluged, OR it can be the mass air (or air density sensor) and/or the TPS (throttle position sensor).
Learn to use the paper clip and the flash codes. That tells you wnat system is malfunctioning, not what part but what system. Its what the computer is seeing. The computer simply makes adjustments to changing conditions/demands based on fixed sets of parameters. It has 2 basic outputs...one is based totally on sensor input and constantly recalculates and the other is pre-programmed to make t he car run with minimal or no fresh data. When the ECM shifts into the 2nd "channel" or mode of operation after warm up, that is the result of a sensor or some other input being out of spec. Thats what the flash codes tell you...what and where to look. look at the coolant sensor plugs and wiring, and the engine harness in general. That might be the warm restart problem. The ECM makes lots of decisions based on what the eng temp is...really is. A tired/hot ignition module that gets too hot can also cause a weak spark.

So, books, test tools and a weekend and you'll be fine.
Trust me, they ALL eventually need attention and the littlest parts can make the worst symptoms. The longer they sit the more they misbehave too..

 

It seems the last 2 posters did not read this part.