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hdkeno's 1969 Firebird

2023 March
of the Month

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I've got a heck of a problem.  Here goes: 2000 Bonneville Stalls,  Cuts back, shuts down while driving,  acts as if not getting gas,  things I have done: Had head and intake gaskets done done by reputable mechanic and one valve replaced, new plugs, lifetime wires, coils, crank and cam sensors ( lifetime warranties ) had ICM checked at autozone 7 times back to back,  test came out ok,  cleaned and greased bottom ICM plate,  cleaned and greased connector harness and coil heads.  New fuel pump and filter.  Unplugged MAF and TPS Got codes so,  they were reading,  only code that appears is #1 cylinder missfire but not constant,  car is still doing same thing,  PLEASE HELP. 

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check your relays for the starter.  My 2002 firebird had a bad one for a while, starting sometimes , and then not starting. Think there are two.

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Does this happen when the car is hot or cold only? Or does it not matter?

Assuming it is a fuel issue, then I would check the fuel tank to see if fuel screen on the fuel level sender is clogged. However, that is expensive since you to remove the fuel tank just to check it.

I much rather suspect some sort of electrical issue. Did the problem start before or after all the engine work was done?

Edited by Frosty
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Another obvious thing to look at would be the fuel injectors. Are they clogged? 

I would inspect all my hoses to see if there are vacuum leaks or broken Ts, etc, especially around the evaporation cannister. This was especially a problem for supercharged 3800s.

Have you checked your fuel pressure at the engine/fuel rail? 

Have you inspected your O2 sensors? Is the catalytic converter clogged? Is there an exhaust leak before the first O2 sensor?

One last thought I have for tonight, did you or your mechanic check/certify that the new crank position sensor works according to spec? Failed crank sensors do a lot of weird things.

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  • 2 weeks later...

Did you get this sorted out? Since it feels like it's starving for fuel, it would be good to know, as Frosty asked, if the fuel pressure at the rail drops when the engine dies. There's a pressure regulator at the end of one rail, I think, on the return line. I've never had to replace one, but if the fuel pressure does drop, maybe... And I'd like to try a different injector in #1 - if a spare is not readily available, switch #1 with #3 and see what code comes up. If still #1, probably not the injector. If #3, probably is the injector. But one bad injector should just make it rough running, not dying.  

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