1989 C4 engine sputters and bogs when accelerating and eventually stalls.
 

Good evening fellow Corvette enthusiast! I am new to the forum and almost at my wits end! I purchased a 1989 one owner Chevrolet Corvette C-4 with 76,000 miles in December from my boss. He took meticulous care of this vehicle and has sat in a garage at work covered for the past 15 years. In December I installed a brand new top-of-the-line battery with a higher CCA as well as A new alternator dura last gold. It ran fine for a month but then started to stall out as soon as I give it gas it sputters and then cuts off. Today I hired a mechanic and we tested the fuel pump and it was dead so we replaced it. Also replaced the fuel filter. Brand new ignition coil. Brand new air filter. Brand new full set of eight Bosch spark plugs. Brand new mass airflow sensor. Brand new fuel pump relay switch. After doing all of this it still sounds completely the same. If anyone has had this issue before please help before I dump any more money into this beautiful blue car prematurely!!

Did your mechanic test for proper pressure after replacing the pump and while engine was running?

Honestly no he did not. It was someone that I found on craigslist because I desperately wanted to get it fixed before it was going to be towed away.

Check the fuel pressure at the rail...you can get a gauge witha long hose or borrow one from an auto parts store (some of them)
Check it wiht the key on, then running, if all is well tape it to your windshield and see what it does under a load; also watch after you shut it off

Do you have the original injectors stil?

Sure sounds like a fuel pressure problem to me. Enough pressure to start and idle but not enough fuel at part throttle. Check the fuel pressure

If the car sat for 15 years there is a chance that debris and gook are in the fuel rail and entrance way to the injectors. Something to look at. I've seen this fool some mechanics.

Welcome to the forum and congrats on the new to you vette!

That's a lot of parts to throw at a problem. I hope he kept your old MAF because some of the new ones don't work the same and might cause MAF codes. If the new one is working without a code then I'd keep the old one as a spare.

Post up pics of the car;)

Here is something you can check on your car. Cost is next to zero will take about a minute to do.

1. Open Hood.
2. Next to battery check the frame for rust. (The rust will be on the frame, you can follow the Negative cable small wire,)
3. If there is rust there take a wire brush and remove it. (The small cable from the Negative cable is connected to the frame there. The big Negative cable ties to the back of the engine on the left side. A cable from the back of the engine left side connects to the frame about an 2 inched from the small negative cable)
4. After removing the rust and cleaning the 2 Ground cables with a wire brush. Replace the cables I painted the area

Ray 1990 6SP Black Vette