Intermittent misfire

[USNChief]

08 Mastiff EFI that runs like crap, only sometimes, no power, backfire, clears up after a mile or 2 . New injectors, new intake gasket. Shop rode it with fuel pressure gauge hooked up inline, good pressure. Anybody experienced this? Could it be electronic?

 

[Little-Boo]

I would check the TPS to make sure it is work within range. I don't have those number for you, but I do know if you TPS is not set right you will experience intermittent performance.

Carlos

 

[USNChief]

Thanks, Carlos. I'll get on the shop. They think it's a fuel problem, but I'm not so sure. At $85.00 an hour, want to narrow down the cause.

 

[DrRx]

08 Mastiff EFI that runs like crap, only sometimes, no power, backfire, clears up after a mile or 2 . New injectors, new intake gasket. Shop rode it with fuel pressure gauge hooked up inline, good pressure. Anybody experienced this? Could it be electronic?

Where did you get the fuel injectors. I'm looking to replace mine.

Thanks doc

 

[dingo]

Steve, I realize you posted this in October but if you haven't resolved yet (and for others experiencing similar problems), you may want to check your coil wiring under the tank. I had a similar problem caused by a chaffed wire under that tank that would ground itself out intermittently. Would run great, then like crap. Keep us posted.

 

[USNChief]

Steve, I realize you posted this in October but if you haven't resolved yet (and for others experiencing similar problems), you may want to check your coil wiring under the tank. I had a similar problem caused by a chaffed wire under that tank that would ground itself out intermittently. Would run great, then like crap. Keep us posted.

Thanks man. Problem solved, turned out it was ECM module. I got a rocket ship now. Sucks I flushed that $$$ on parts I didn't need, but at least it's all brand new now. And a little satisfaction that I was right about being electronic issue.

 

[dingo]

Thanks man. Problem solved, turned out it was ECM module. I got a rocket ship now. Sucks I flushed that $$$ on parts I didn't need, but at least it's all brand new now. And a little satisfaction that I was right about being electronic issue.

Glad you got it worked out !

I did the same thing....I ran all the diagnostic tests and the chaffe was so tiny and intermittenet that I missed it until after I replaced the coil, plug wires and thunderheart module. As Paul says, I have a bunch of good spares now.

 

[DrRx]

Glad you got it worked out !

I did the same thing....I ran all the diagnostic tests and the chaffe was so tiny and intermittenet that I missed it until after I replaced the coil, plug wires and thunderheart module. As Paul says, I have a bunch of good spares now.

Glad you got it running. Can you tell me where you found your fuel injectors at?

 

[dingo]

Glad you got it running. Can you tell me where you found your fuel injectors at?

Sorry, I have an 06 so mine is a carb setup.

 

[USNChief]

Glad you got it running. Can you tell me where you found your fuel injectors at?

Came from S&S, 2 pack part # 55-5052.

 

[DrRx]

Does anyone know where t get the fuel pump filter at

 

[Tdubb]

Does anyone know where t get the fuel pump filter at

Walbro filter 125-192. Same part for my 2008 EFI Mastiff. $8-$10. You'll need new oetiker clamps. Those are: small clamp 15400040(17.5RER). large clamp 15500029 (0455.0R)

 

[willywill4765]

Can you tell me what you did with your ECM module or how you fix yours my 07 bulldog misfires every so often also

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