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Flutter under boost


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WHenever i hit boost, instead of accelerating i hear a bunch of flutter comming from my motor.

 

The boost gauge stays solid at 5psi... engine hesitates but doesnt really accelerate like theres 5lbs of boost.

 

I checked for leaks when i got home but found none. Could it be bad timing?

 

-Brian

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Well the wierdest thing.

 

The other day after I dropped the motor in, i checked the timing and it was at 10 degree's. I took it on a few test runs and checked again when i got done, and it showed to be at 22 degree's. So I took it down to about 20 degree's and have left it since.

 

Drove it to work for the 1st time yesterday and today. Noticed in the morning if I feather the throttle it runs fine, if i gass it at all (boost or no) i get flutter and the car just doesnt pull like it should. Tonight I got home and I checked it and the timing said it was at 10 degree's :confused: So i bumped it up to 20 and took it for a test run. No more hesitation. Also no flutter and the pull I Was looking for is back.

 

I really need to get my intercooler on there.

 

-Brian

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Well the wierdest thing.

 

The other day after I dropped the motor in, i checked the timing and it was at 10 degree's. I took it on a few test runs and checked again when i got done, and it showed to be at 22 degree's. So I took it down to about 20 degree's and have left it since.

 

Drove it to work for the 1st time yesterday and today. Noticed in the morning if I feather the throttle it runs fine, if i gass it at all (boost or no) i get flutter and the car just doesnt pull like it should. Tonight I got home and I checked it and the timing said it was at 10 degree's :confused: So i bumped it up to 20 and took it for a test run. No more hesitation. Also no flutter and the pull I Was looking for is back.

 

I really need to get my intercooler on there.

 

-Brian

Are you connecting the green connectors when you check for timing?

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If I'm not mistaken, you need to connect the green connectors when you check timing. Otherwise the timing will be all over the place.

 

this is correct. setting timing with out connecting the green connectors is not verry acurate at all.

you may have an additional problem sure but set the timing properly first.

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just a simple thought... ive decided on mine that screwdriver tight on the clamps from the turbo to intake isnt tight enough... use a wrench.. mine was fluttering underboost, when i would look at it everything seemed ok.. but really tightening them down fixed the problem..

 

 

rllywgn

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Thats a good idea, i may have to go do that. When i put all that on, i was eager to get the car running so I wonder if maybe i didnt tighten the intake plentum tight enough?

 

I did connect the green connectors and my CEL went off (oh yeah, it came back on yesterday and has been on all day). Then i checked the timing and it was at 18 degrees. So i bumped it up to 20 degrees and went for a test drive.

 

Still some hesitation but im hoping the intercooler fixes some of that.

 

-Brian

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Still some hesitation but im hoping the intercooler fixes some of that.

 

-Brian

 

 

if you have hesitation without the intercooler... adding one will most likey exacerbate the problem.. most intercoolers will have some pressure loss and could add to more so then correct the problem..

 

 

rllywgn

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sorry bout that.. first time i ever put that word on paper.. or screen in this case...

 

basically what i meant was adding the intercooler will possibly make the hesitation worse.. i had a similar problem on a ea82t wagon some time ago.. it had some early-mid throttle hesitation, when i added a dsm intercooler it would nearly choke off the line.. the intercooler accounted for a 3psi pressure loss and along with the hesitation it was to much to handle..

 

 

rllywgn

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Yeah, ive run this Intercooler before, on the old engine and it was nowhere near 3psi drop (what did you have? a kenworth Front Mount?)

 

With the stock engine it was a night and day difference with the intercooler and without. With the intercooler I had hardly any hesitation under boost and acceleration (well, until my knock sensor went bad... different story).

 

Oh, and with the high comp pistons, i can afford to give up 3psi if i have to.

 

-Brian

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