1987 Pontiac Firebird



December, 18, 2010 AT 8:26 PM


I recently purchased a 1987 Firebird 5.7 Liter as-is. Car only has 75K miles on it.
I put a new battery in and turned the key. It barely ran and then stalled out. I checked the fuel gauge and it said I had a quarter tank. I thought the fuel pump was bad so I replaced it and also found out that there was no gas in the tank to begin with. The only thing in there was what looked like injector cleaner. That most likely explains why it smoked so much when I started it.

So I installed the new pump and sending unit and filled with gas. Tryed to turn over, but nothing. After a while the starter began to click and I realized the vehicle was Hydro Locking, from an overload of gas in the system.

In that time period I have replaced the Coil, Ignition box (on the distributor), fuel pressure regulator, Coolant sensor and Bosch +4 spark plugs.I have a nice fat spark.

I partially took out the fuel rails with the injectors and turned the key for one click. Each injector shot out about 1/4 of a bottle of water into the engine. I now have a ton of gas in my oil and still have a lockup problem.

I don't know what's wrong and am getting ****ed off. Is it a bad ecm?

Also, I have a check engine light. When I hook up the two terminals on the OBD1 I get the error code 12. No other numbers, I don't know why. Also the cooling fans for the radiator randomly turn on???

I just took out all the spark plugs, unplugged the injectors. I turned the key for a few seconds and there was some gas that blew out onto the manifold. However the injectors are not leaking. I also just changed the oil and it had at least 2 quarts of gas that mixed with it.

I wouldn't know what to diagnose. I know that I have spark and the injectors are not leaking. Somethings telling the computer to give more gas??? I was told by a mechanic to test the temperature coolant sensor, and I just replaced it.

I just cleaned out the cylinders, put new oil in and disconnected the injector wires and it started right up. Well then it died, so I reconnected the injector wires and I caught the underside of the car on fire. I was video taping it. Maybe this can be helpful in solving the problem. Could the MAF sensor be causing this problem. Maybe the ECM. Heres the video. -

Any help would be appreciated,


3 Answers



December, 18, 2010 AT 11:03 PM

I would be thinking that a faulty MAF or a TPI sensor is part of the problem, can you get an OBD11 scan and codes, these are better to work with than flash codes, I would be fitting up the exhaust before any further attempts at starting and check for fire damage, do this run the scan and let me know what codes, this may even be a faulty ECU causing over extender injection duration.

Mark (mhpautos)



December, 19, 2010 AT 3:18 AM

Thanks for assistance.

I installed a new ECU after trying to test the injector wires, as the voltages weren't right. The car fired right up.




December, 19, 2010 AT 3:48 AM

Good result, thank you for using 2carpros.

Mark (mhpautos)

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