1996 LT 1 Auto, car sat for about 8 years before I bought it. So far I haven't been able to get it to start.

The injectors aren't spraying any fuel when I try to start the car. I just got a noid light tonight and confirmed no injector pulses. No codes show up when I hook up a code scanner.

Background on what all I've changed/tested so far:
I've changed plugs, wires (one was cut in half), and fuel pump (completely corroded).
I tested for spark at two plugs by pulling the wires and sparking against the block.
Cleaned the gas tank, flushed the fuel system, pulled and cleaned the injectors.
Injectors are all measuring between 12 and 12.2ohms. A couple were stuck closed but freed up after cleaning and bench testing.
Injector plugs are showing 12v.
Fuel pressure after pump has primed is around 45-50psi.
TPS voltage at closed is .53, open is 4.2.
I checked a couple of the injector signal wires for continuity at the PCM plug and they wire fine.
Tried starting with and without the MAF sensor connected.
I sprayed a little starting fluid in the throttle body and the engine sputtered a bit and sounded like it wanted to start.
Dash and electronics all seem to be working.
Aftermarket opti installed by PO. Vacuum lines don't appear to have ever been connected. The vacuum line from the intake manifold that should have gone to the opti was shoved into a hole in the air intake ducting.
There are 3 vacuum lines that are broken and I haven't fixed yet. Two on the passenger side of the intake manifold that go into the wire loom and one from a T that goes under the battery.

From what I've been reading if the Opti was bad I'd be getting a trouble code and no spark. Any ideas on what else I can check? I've seen a couple mentions that bad grounds to the PCM could affect the injector pulse lines since they're just grounds as well.

What's the best way to test those? A continuity test between the PCM plug pins and another ground source or measuring voltage between them and a power source?

 

Are you using factory service manuals? Sections 6E has DTC and driveablity diagnosis and 8A wiring diagrams and component locator. From what you are describing substituting a PCM would be a good idea. The PCM is the same as the full size and f body although programming is different. Ideally I would barrow or buy a known good used PCM from pick n pull or off Craigslist. AFAIK dealer has to reprogram PCM

 

Any idea of a dealer could run diagnostics to see if the PCM is bad?

 

There is no dealer tool to plug GM PCM into to test them. Because it's a 96 you need to call ahead to find out if they will work on it. Testing will follow FSM cranks but won't start chart.

 

Well, weird update. I reinstalled the injectors and fuel rail and decided to try the noid light again and I’m getting signal. Plugged the injectors back in and it almost started but then one of my injectors failed and is stuck open. I guess I damaged it while cleaning or it was just it’s time to go. Just ordered a set from FIC.

 

Stay away from the dealers! A local Corvette shop yes! You want some one who daily works on these cars. You can also ask a lot of questions here, but do not throw parts at it. Not being run for 8 years why? Did they have a problem with it prior to storage? Check history if you can and just keep on trying.

 

Well a dealer has a better chance of having any specialized equipment required along with someone who specializes in Corvettes. Smaller sports car shops may or may not. The main thing is their reputation. There are plenty of SWAGs and parts changers. it lies in the integrity of the person working on your car. Possibly member here or in local Corvette club can refer you.

 

So more background on me and the car:
I have some automotive experience. Shocks, steering, fluids, lights, engine bolt ons, etc. I've worked on and owned a 67 Lemans, 2011 Silverado 1500, and a 2017 Camaro SS.

Ideally I'll be doing this on my own. I only asked if a dealer could check the PCM because I want to do everything I can to make sure a part is bad before just replacing it. Especially when it's something over $100-$200. I picked the car up pretty cheap knowing it wasn't running. I wanted an inexpensive (to purchase) project to work on for the winter.

I don't know much about this car. I bought it from a guy that had it for maybe a month before his wife told him to fix it or get rid of it. He already had 3 other projects vehicles. He said the PO had it for 15 years and was a "mechanic". I use quotes because I don't think a real mechanic would have twisted injectors wires together and wrapped them in electrical tape as a repair or installed a new opti without attaching the vent hoses.

The registration sticker says 2010 so that's why I assume it sat for ~8-9 years. All of the weather stripping is dry rotted and broken down, the gas cap was stuck (had to break it into pieces to remove), the bottom of the tank had a layer of sediment in it, and the paint has a lot of cracking so I also assume it sat outside for most of that time.

I have the fuel system sorted out to the best of my knowledge.

• Drained the tank, cleaned it out, installed a new sender unit, and gas cap.
• flushed the lines
• new fuel filter
• cleaned and tested the injectors (and broke one along the way). Refurbished bosche injectors are on order from FIC.
• Injectors have 12v power, they did not have a pulse signal until yesterday though.
• Checked the fuel pressure regulator vacuum port for fuel. Didn't find any.

Ignition system:

• New spark plugs (One of them was a different part number than the rest)
• New wires (one of the old wires was cut in half, they appeared to be original)
• Opti doesn't look OEM. It's a black body with yellow back.
• I checked spark at two wires so I'm assuming ICM, coil, and opti are good.

I did hear some combustion when I tried to start it yesterday but then one of the injectors went bust and is frozen open. I'm hopeful a new set of injectors will at least get the engine to start running.

Once I confirm the engine will at least start and stay running I'll start on other maintenance items:

• Check timing
• Possibly pull and clean the opti.
• Oil change
• Tires
• Air filter
• Clean the MAF
• Water pump (removed the old one to get a better view of the opti and make changing wires easier)
• New opti vent lines
• Brake fluid, and probably pads and rotors
• Finish repairing vacuum lines
• New belt

Then after I've put some miles on it so I know it's mechanically sound and decide I want to keep for 3-5 years, I'll look into other items:

• Needs a new passenger louver panel and driver rocker panel
• Pull out the interior and clean the carpet, seats, plastic panels
• Doors need a little TLC. The windows go up and down but slowly. I'm guessing some cleaning and proper lubrication will help
• Weather stripping
• Tint
• Sand down and paint cracks/bubbles, smooth out the body, and do a vinyl wrap.
• Refinish wheels
• Modern head unit
• Heads/cam/headers