No start on '85 GT (Page 1/3)
jumpmonkey APR 30, 10:24 PM
I recently purchased a barn find '85 GT.

I thought that I had figured out the issue for why it refused to run. In this thread I went over why I thought it was the fuel pump and the symptoms I had. The post seemed to be met with agreement from other members. I replaced the pump,sending unit, and fuel filter with parts from the Fiero Store. I also cleaned the tank while I was at it. Today, I finished buttoning everything up(I didn't fully mount the tank, just the hoses and lines) and went to start the car. I primed it a few times and expected to hear a mighty roar! The awakening of a sleeping giant.
nothing...nothing but cranking.
Alright, enough theatrics
The fuel pump is operating. I can hear it prime when I turn the ignition to on. While my dad and I were trying to get the car started, he placed a hand on the tank while I cranked the engine and could feel the pump working. I did disconnect the line coming out of the fuel filter and gas started spewing out so we have fuel movement. I know that the engine wants to start, too. We tried using a bit of starting fluid, to help get the engine fired up, and it sounded good when we'd get it going for a bit.
Don't really know where to go from here. If the engine turns over well with starting fluid, we have spark and I assume compression. And I would think that fuel would no longer be an issue. Needless to say, no start.
Any suggestions on what to look for next would be great. I was thinking plugged up fuel injectors.

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Jumpmonkey

Mike in Sydney APR 30, 11:43 PM

quote
Originally posted by jumpmonkey:

We tried using a bit of starting fluid, to help get the engine fired up, and it sounded good when we'd get it going for a bit.
Don't really know where to go from here. If the engine turns over well with starting fluid, we have spark and I assume compression. And I would think that fuel would no longer be an issue. Needless to say, no start.
Any suggestions on what to look for next would be great. I was thinking plugged up fuel injectors.






Could be the injectors but try changing the fuel filter if you haven't done that already.
Patrick APR 30, 11:58 PM

quote
Originally posted by jumpmonkey:

And I would think that fuel would no longer be an issue.



I see no mention made of an actual fuel pressure reading.
cartercarbaficionado MAY 01, 03:20 AM

quote
Originally posted by jumpmonkey:

I recently purchased a barn find '85 GT.

I thought that I had figured out the issue for why it refused to run. In this thread I went over why I thought it was the fuel pump and the symptoms I had. The post seemed to be met with agreement from other members. I replaced the pump,sending unit, and fuel filter with parts from the Fiero Store. I also cleaned the tank while I was at it. Today, I finished buttoning everything up(I didn't fully mount the tank, just the hoses and lines) and went to start the car. I primed it a few times and expected to hear a mighty roar! The awakening of a sleeping giant.
nothing...nothing but cranking.
Alright, enough theatrics
The fuel pump is operating. I can hear it prime when I turn the ignition to on. While my dad and I were trying to get the car started, he placed a hand on the tank while I cranked the engine and could feel the pump working. I did disconnect the line coming out of the fuel filter and gas started spewing out so we have fuel movement. I know that the engine wants to start, too. We tried using a bit of starting fluid, to help get the engine fired up, and it sounded good when we'd get it going for a bit.
Don't really know where to go from here. If the engine turns over well with starting fluid, we have spark and I assume compression. And I would think that fuel would no longer be an issue. Needless to say, no start.
Any suggestions on what to look for next would be great. I was thinking plugged up fuel injectors.




ah the lovely crappy tbi injection. check fuel pressure and that the injectors spray at cranking speed, quick and dumb way to check pressure is to let it pressurize and then find the Schrader Valve and poke it with a screwdriver after you disconnect the coil on all sides, the fuel geyser should be around 4 to 6 inches tall. aka if it touches the decklid its perfect
1985 Fiero GT MAY 01, 05:54 AM
Double check your fuses, the Fiero has 2 fuses for the v6 injectors, if those are blown or removed, it won't run.
olejoedad MAY 01, 07:19 AM
Plugged injectors, low fuel pressure, bad IGN1/IGN2 fuses......
jumpmonkey MAY 01, 08:18 AM

quote
Originally posted by Patrick:

I see no mention made of an actual fuel pressure reading.



I may be able to borrow a fuel pressure gauge from someone I know. Or I can test it how cartercarbaficionado suggested. What would the psi specs be?

I had checked those V6 fuses when I first tried getting the car to run and one was blown. I replaced it. I'll check both of them again.
If the fuel pressure is good and both fuses aren't blown, would I need to move towards cleaning up the injectors?
olejoedad MAY 01, 09:17 AM
The injectors.always have 12vdc on the pink wire with the key on.
Check that first.
The injectors fire when the ECU supplies a ground.
The 2.8 is a bank fire design, that means that all of the injectors on one side of the engine open at the same time, and the sides alternate .
You can check for voltage at the injector sub-harnes to engine harness plug.
Separate the plug and probe the pink wires with the key on.
You should see 12vdc.
If you do, you can get a noid test light to check that the ECU is supplying the ground to fire the injector.
If there is pulse on the noid light, and you have fuel pressure (≈40psi), chances are the injectors are plugged.
I would spend the money to replace them, rather than try to clean them.
fierofool MAY 01, 04:59 PM
The fuel system can prime but if the ECM doesn't see spark, it won't run the fuel pump at crank.

I've seen this more than once. Disconnect the large harness that plugs into the ignition control module. Look into the end of it to be sure that all the clips inside are almost flush with the end. They should all be equal. I believe it's the 3rd from the right as you look at it when it's plugged in. That's the one that signals the fuel pump to run. The clips inside sometimes get pushed back into the harness end and they don't make contact.
jumpmonkey MAY 02, 08:20 AM

quote
Originally posted by olejoedad:

The injectors.always have 12vdc on the pink wire with the key on.
Check that first.
The injectors fire when the ECU supplies a ground.
The 2.8 is a bank fire design, that means that all of the injectors on one side of the engine open at the same time, and the sides alternate .
You can check for voltage at the injector sub-harnes to engine harness plug.
Separate the plug and probe the pink wires with the key on.
You should see 12vdc.
If you do, you can get a noid test light to check that the ECU is supplying the ground to fire the injector.
If there is pulse on the noid light, and you have fuel pressure (≈40psi), chances are the injectors are plugged.
I would spend the money to replace them, rather than try to clean them.



I will test for 12V and fuel pressure tonight. I'll check the V6 Injectors fuses, too. I'll update the thread.

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Jumpmonkey