Hi Everyone, I recently purchased a stock, base model 88 Fiero. The previous (original) owner said that the car hasn't run for 4-5 year. CarFax shows that it last passed inspection in 2000. Anyway, the engine cranks but will not start. Using starter fluid, the engine will start but not continue to run. The TBI is not spraying gas into the bowl. There is gas on both sides of the fuel filter - which we replaced. The gas is fresh - drained what little remained from the previous owner. Do any of you have troubleshooting ideas please? Particularly on how to check and clear the fuel line from the fuel filter to the carburetor. I'm not sure what else would prevent the TBI from spraying fuel. Thank you!
It's actually a throttlebody (TBI), not a carb. The line is probably fine, check the fuel pressure at the TBI, should be 14ish. Low pressure is probably a bad hose at the fuel pump (in tank). Injector may need to be cleaned or replaced. Rebuild the TBI, GP Sorensen kit # 96-626B
Check with a test light or multimeter to see if TBI is getting power and opening to spray fuel. Rent a fuel pressure tester from Autozone or similar and check fuel pressure in fuel rail.
If you have fuel pressure and the Injector is getting power, then it is an issue with injector. It may need to be cleaned or replaced.
If no power to injector, start by checking the INJ fuse. If there is power to injector but the other side is not grounding, then could be an issue with ECM or wiring from ECM. Fuel injectors are hot with key on and ECM grounds them to complete circuit. Use a test light from hot side of injector to some clean bare metal on the motor to make sure it has power and has current too, I have found wiring that is at 12 volts with a multimeter but will not light up the test light because the wire was mostly broken.
If you get no fuel pressure, you will have to drop the tank to see if the rubber line connecting the fuel pump to the fuel line is split. This is very common when someone replaces the pump without using a submersible fuel hose, regular fuel hose is not rated to be submerged in gasoline and will break down relatively quickly and split inside the tank. I would go ahead and replace the pump while you are in there because it is a pain to get to that point. Obviously make sure to use a submersible fuel hose piece to replace it. And make sure to buy the 4cyl pump instead of the 6cyl pump because it is lower pressure. Also see if it is rusty inside your tank because that can kill fuel pumps and clog fuel filters.
I would go ahead and replace the fuel filter too, it is cheap and might as well just do it now.
87+ TBI is near "bullet proof" and injector rarely fails.
1. Turn key on Do Not start. Does fuel pump runs for a few seconds? Should hear it run. Yes then... 2. look into oil fill hole and watch the rockers as someone tries to start the engine... If no moving there the timing gear likely failed. 3. If the rockers move... check for spark... ECM will Not turn on the Injection w/o a spark first. ⚠️ Warning: Ignition coils can hurt you or self destruct if test for spark is done wrong. 4. with a spark, ECM can be "bad" and still not run the injection.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Thank you everyone! I’ll run through troubleshooting and let you know how it goes. I hope I don’t have to drop the fuel tank, but if that’s what it takes, then that’s what it takes.
Well, it is at least a bad fuel pump. It does not come on when the ignition is in the On position. New fuel pump on the way, along with strainer and fuel sending unit - which is also bad. I'm betting I will see a lot of corrosion and other bad stuff once we pull the tank and get inside. I will keep you posted - and thanks again everyone!
New fuel sending unit and pump are ready to go on the tank once it finishes drying out. The tank needed a thorough cleaning to get out all of the gunk, rust, and other flaky material. I connected the power to confirm that the pump comes on when the key is in the On position. The gas gauge works now too. The fuel pump is for an 87 Buick Grand National, so I think I will have enough psi for fuel delivery. Thanks again for all of your input!
Latest update: Fuel pump is replaced and working correctly. We can hear and/or feel fuel moving through the line all the way up to the throttle body. There is no fuel spray from the injector. Both TBI 5 amp fuses are good. It appears that the next step is to check that the injector is getting power. Is that correct? Are there any other suggestions? Thank you in advance - this is a fantastic forum filled with good and knowledgeable people!
Have you solved the problem yet? Sounds like the next thing to do is put a noid light on the injector connection. Sounds like the computer is not telling the injector to fire. Noid light will confirm that.
New fuel pump, fuel sending unit, and injector, along with cleaning the fuel tank did the trick. Started with the first key turn and no starting fluid.
The 88 takes a Bosch PFI noid light to check the circuit, which fortunately works as installed.
New fuel pump, fuel sending unit, and injector, along with cleaning the fuel tank did the trick. Started with the first key turn and no starting fluid.
The 88 takes a Bosch PFI noid light to check the circuit, which fortunately works as installed.
