1988 Pontiac Firebird No Signal

Hello –

I need some more specifics on your vehicle to better assist you. Is your vehicle just a Firebird, or a Firebird Formula, Firebird Trans AM, or Trans AM GTA? Also, I need the engine size in liter and the 8th digit of your VIN.

Just a couple of questions to get on the same page. Why did you replace the starter and alternator?

So if I understand, the car was running just fine….you replace the starter and alternator and now it is doing this?

Next, if it is drivable, please go to Auto Zone (AZ) or O’Reilly’s (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don’t get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery, alternator and starter.

Now I know you just replace the alternator but I want to see how it is reacting with the battery and in the car.

If you can not drive it….then you can check the code scanner out from AZ and check the codes yourself and then please let me know the info above.

We need to figure out if it is electrical or fuel related. Pull a plug wire off of the spark plug and insert something into the end of it and have someone try to start the car and have the metal object really close to a piece of metal on the engine and see if you are getting a good strong popping blue spark. Don’t have your hands on any part of the metal!!! If there is no spark, then it is electrical. If you are getting good spark then you need to get a fuel pressure check on the fuel pump to ensure it is putting out okay.

Do the above and please get back with me.

The Tachometer is operable but I am getting no signal to the ALDL prom, to therefor when I scan for trouble codes, the scanner is blank, thie is a 1988 Pontiac Forebird and according to the Vin # it is a formula the vin is 1G2FS21E0JL2*****/the engine is a 305 cubic inch/5.0 liter Throttle Body injection The previous starter was replaced due to damage from the headers and due to a servere drop in amperage I replaced the alternator but and as of today I also replaced the Fuel pump relay furthermore I pulled the fuel tank to test the fuel pump and it is operablebut after connection and reassembly I am still having the same trouble, so there is something blocking signal to the fuel pump.But the car is by no means driveable since it will not start, the engine only rotates.

Hello - Simpimp From what I can see of your car.....nice looking and in good shape. Thanks for the info..... Let's see what we can do here...... First are you sure you are getting spark? Have you pulled a couple of plug wires and made sure you have a good hot blue spark? Next, I have attached a pic showing where the fuel/oil switch is. If this is defective it will not allow the car to start. Next, I have attached info on the fuel pressure. Sounds like you did a lot of work today...are you able to check the pressure?

FUEL SYSTEM PRESSURE RELEASE 4 & 8 Cylinder Engines With engine Off, remove fuel pump fuse from fuse block. Start engine and allow to run until fuel supply is exhausted. Crank engine an additional 3 seconds to ensure fuel supply is exhausted. Install fuel pump fuse. On 4-112 and 4-121 overhead valve engines, install fuel pressure gauge between throttle body side of fuel filter at the rear of the car. On 4-151 engines, install fuel pressure gauge between TBI unit and steel fuel line. On V8 engines, install fuel gauge between front and rear TBI units steel fuel line. Start engine and observe fuel pressure. It should be 9 to 13 psi. Relieve fuel system pressure. Refer to steps 1 through 3 above. Remove fuel pressure gauge and reinstall fuel lines. Start engine and check for fuel leaks. FUEL SYSTEM PRESSURE TESTING Before servicing fuel system components, fuel system pressure must be released. To relieve pressure, proceed as follows: Remove fuel pump fuse from fuse block. Run engine until fuel remaining in lines is consumed. When engine shuts down, engage starter for approximately three seconds to relieve any remaining pressure. With ignition off, replace fuel pump fuse. Remove air cleaner and plug THERMAC vacuum port on throttle body unit. Remove fuel line between TBI unit and fuel filter or between front and rear TBI units on ``Crossfire'' injection systems. Use a suitable back-up wrench to hold flare nut on throttle body when removing line. Install fuel pressure gauge J-29658 or equivalent, between throttle body and filter or, on ``Crossfire'' systems, between front and rear TBI units. Check pressure reading with engine running. If fuel pressure is not between 9 and 13 psi, refer to ``Fuel System Diagnosis.'' De-pressurize fuel system, remove pressure gauge and reinstall fuel line. Start engine and check for fuel leaks. Remove plug from THERMAC vacuum port and install air cleaner.