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Rough !!!

  • Carstuff
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5 years 11 months ago #34274 by Carstuff
Rough !!! was created by Carstuff
07 mazda6 v6
Runs Rough and stalls . Bogs down no throttle response
Injector signal

All injectors are similar in the signal test but where is the pintel hump ??

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5 years 11 months ago #34275 by Carstuff
Replied by Carstuff on topic Rough !!!

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5 years 11 months ago #34282 by Cheryl
Replied by Cheryl on topic Rough !!!
That looked like ignition testing not injectors. Also try unplugging coils to do a power balance test

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5 years 11 months ago #34283 by Carstuff
Replied by Carstuff on topic Rough !!!
its the fuel injector connector. 3 front coils are firing but the 3 rear is under the manifold cant do any removal test

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5 years 11 months ago #34288 by Noah
Replied by Noah on topic Rough !!!


The green trace on the right is a fuel injector voltage waveform. The little bump near the end of the slope after the spike is the pintle movement.
Like Cheryl said, your pattern looks like an ignition waveform. I'm curious to know how you obtained that pattern from a fuel injector.
"Ground cannot be checked with a 10mm socket"
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5 years 11 months ago - 5 years 11 months ago #34303 by Carstuff
Replied by Carstuff on topic Rough !!! odd issue
which vehicle did you get that injector pattern from ? Im use to seeing that pattern on other vehicles however this mazda6 fuel injector waveform is different. which is odd. even the waveform snapon is displaying is just like what you just posted in the green. its the fuel injector not a ignition coil. im backprobing the wires that the snap-on scanner is telling me to. in the video you could see at the top saying saying fuel injector channel 1 signal and black to ground .
Last edit: 5 years 11 months ago by Carstuff.

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5 years 11 months ago #34304 by Carstuff
Replied by Carstuff on topic Rough !!! odd issue
fuel pressure at idle and at wide open throttle to the floor underload stays around 68psi regardless of the poor throttle response.

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5 years 11 months ago #34305 by Cheryl
Replied by Cheryl on topic Rough !!! odd issue
Is it a misfire? Or just bogs down???

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5 years 11 months ago #34309 by Carstuff
Replied by Carstuff on topic Rough !!! odd issue
engine is shaking. it bogs down . wide open throttle doesnt move the vehicle. feels like your pulling a boat going up a hill. you could hear the rpm pulling .

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5 years 11 months ago #34310 by Carstuff
Replied by Carstuff on topic Rough !!! odd issue
mode 6 only shows misfire date for each cylinder as passed. theres no live misfire counter. in park if you rev it and try to hold the rev at any rpm speed it has trouble holding it solid. try holding it at 2k all it does it drop to 1700 to 2000 to 1850 .
the throttle body does open at 100% as its electronic

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5 years 11 months ago #34312 by Cheryl
Replied by Cheryl on topic Rough !!! odd issue
What’s the o2 sensors do at wide open throttle?? They go rich? Have you checked exhaust back pressure? Can you post some live data videos? Oxygen sensor fuel trim data while bogging. Does it have variable valve timing? Maybe a solenoid is stuck

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5 years 11 months ago - 5 years 11 months ago #34315 by Carstuff
Replied by Carstuff on topic Rough !!! odd issue
its a vvt. at wide open throttle it bank1 stays lean 0 open loop stuck no change. wide open throttle when the engine is cold is the same as if its in closed loop. when I checked backpressure its only showing 1psi to 1.4 psi , reving it up shows only 1.5psi
Last edit: 5 years 11 months ago by Carstuff.

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5 years 11 months ago #34510 by Carstuff
Replied by Carstuff on topic Rough !!!


when driving pedal to the floor you could hear what seems to sound like a two-step popping from exhaust under hood.

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5 years 11 months ago #34511 by Cheryl
Replied by Cheryl on topic Rough !!!
I think you have a restricted converter. Pull the o2 sensors and check the back pressure. I think you’ll find your issue. Please upload video of the tests

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5 years 11 months ago #34520 by johnathon.balderas
Replied by johnathon.balderas on topic Rough !!!
he stated he had only 1 psi of backpressure. that's definitely not excessive.

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5 years 11 months ago #34521 by johnathon.balderas
Replied by johnathon.balderas on topic Rough !!!
It's definitely running lean on 1 bank evident by the fuel trims and the intake backfire

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5 years 11 months ago #34524 by Cheryl
Replied by Cheryl on topic Rough !!!
What bank was that test on with 1 psi only?? Bank 1? Bank 2? Sounds like he only checked 1 bank. Every time I see super rich and super lean it’s been a restriction. S

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5 years 11 months ago #34528 by Carstuff
Replied by Carstuff on topic Rough !!!
Both banks backpressure reading

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5 years 11 months ago #34529 by Carstuff
Replied by Carstuff on topic Rough !!!

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5 years 11 months ago #34530 by VegasJAK
Replied by VegasJAK on topic Rough !!! odd issue
I'm seeing a fuel pressure problem here... idle pressure and WOT should not be the same. This would indicate a pressure regulator stuck shut. Idle pressure should be 10 or so lbs lower than WOT. Check the vacuum at the regulator. If no vacuum at idle, you have a leak. If vacuum, the regulator is stuck shut.
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