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NEW 347 WON'T IDLE

  • Thread starter Thread starter Zeffer
  • Start date Start date Nov 29, 2021
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General karthief

wonder how much it would cost to ship you a pair
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Dec 5, 2021
#21
  • Dec 5, 2021
  • #21
What is your vacuum reading?
 
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Zeffer

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Dec 5, 2021
#22
  • Dec 5, 2021
  • #22
Had it running tonight (sort of) vacuum gauge only shows about 10" and I swear I can hear a distinct high pitched whistle like a vacuum leak. I've smoke tested it and only thing that seemed weird was a lot of smoke from oil filler cap, replaced pcv just because, new one acted just like the old one. I used my stethoscope trying to pinpoint the noise and can't seem to, however when I removed the oil fill cap and put the stethoscope hose in the noise seemed to be pronounced.
At this point I feel I have an intake manifold leak from intake to valley, the vacuum gauge seemed to fluctuate in a pattern as well.
Any thoughts guys??
As always, thank you for your help!
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
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Dec 5, 2021
#23
  • Dec 5, 2021
  • #23
What make tb?
I chased a whistle that I was told was a vacuum leak and it was my BBK tb. With only 10" of vacuum I think it is a vacuum issue. ..when the engine is running can you feel vacuum at the oil fill tube, you have to pull the hose from the tb and plug that nipple,
 

Zeffer

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#24
  • Dec 5, 2021
  • #24
General karthief said:
What make tb?
I chased a whistle that I was told was a vacuum leak and it was my BBK tb. With only 10" of vacuum I think it is a vacuum issue. ..when the engine is running can you feel vacuum at the oil fill tube, you have to pull the hose from the tb and plug that nipple
Click to expand...
Funny you should mention that...I never noticed this whistle until I replaced the throttle body, had a BBK and I replaced it with a BBK. If that is what is causing the whistle, how do you get rid of it? I will try plugging the TB hose to the fill cap and check for vacuum tomorrow.
Thank you!
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,915
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polk county florida
Dec 5, 2021
#25
  • Dec 5, 2021
  • #25
Ahhh, I heard a few things, rounding off the sharp edges at the opening for the IAC was the mentioned the most, I just lived with the whistle,
 

j753303

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Dec 6, 2021
#26
  • Dec 6, 2021
  • #26
i ended up buying an accufab TB
 
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Zeffer

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Dec 7, 2021
#27
  • Dec 7, 2021
  • #27
It had a BBK on it when I bought the car.....didn't whistle, go figure!
What do you all think of my low vacuum issue?
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
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Dec 7, 2021
#28
  • Dec 7, 2021
  • #28
Obviously a vacuum leak, likely intake manifold gasket.
 

7991LXnSHO

wanna catch the space herp
10 Year Member
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Dec 11, 2021
#29
  • Dec 11, 2021
  • #29
General karthief said:
Ahhh, I heard a few things, rounding off the sharp edges at the opening for the IAC was the mentioned the most, I just lived with the whistle,
Click to expand...
I like the F# when the IAC is working. It’s not like the car is quiet enough for that to be annoying.
On the old hosting service, (so it should still get searchable here), there was a thread how to of exactly how to round off the air passages with a Dremel.
 

Zeffer

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Dec 12, 2021
#30
  • Dec 12, 2021
  • #30
OK....
I totally eliminated all vacuum lines to the engine and smoke tested just the engine, plugged off pcv at intake as well as vent to oil fill tube. Not a leak to be found, this eliminates the intake manifold gasket. Put all vacuum lines back on and smoke tested again, nothing seen. I'm pretty confident I don't have any vacuum leaks. I performed the base idle reset procedure to a tee, set timing to 12 degrees, adjust tps (only could get it to 1.05v) which I assume is OK?
Unhooked battery for 10 minutes, plugged in IAC and started engine, it now seems to idle with a minor surge. The vacuum is only 10" is this the best I'm going to get with my cam choice?
 

Zeffer

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Dec 12, 2021
#31
  • Dec 12, 2021
  • #31
Video of vacuum at idle...
View: https://youtu.be/o5RscNliPOQ
 

Zeffer

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Dec 12, 2021
#32
  • Dec 12, 2021
  • #32
Fuel pressure at idle...
View: https://youtu.be/vtmFb3gkGQM
 

Zeffer

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Dec 12, 2021
#33
  • Dec 12, 2021
  • #33
Idle rpm....
View: https://youtu.be/Whkrn2notvM
 

Zeffer

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Dec 12, 2021
#34
  • Dec 12, 2021
  • #34
New to forums....sorry for all the separate video posts!!
Anyone have any comments on the videos or something that I need to check further?
BTW, I have my valves set at zero lash and then 3/4 turn, is that correct?
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
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Dec 12, 2021
#35
  • Dec 12, 2021
  • #35
What is that check engine light on for?
 
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Zeffer

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Dec 12, 2021
#36
  • Dec 12, 2021
  • #36
No egr anymore
 

Boostedpimp

20+ Year Stangneter
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Dec 14, 2021
#37
  • Dec 14, 2021
  • #37
Zeffer said:
The vacuum is only 10" is this the best I'm going to get with my cam choice?
Click to expand...

I would think with that cam at 850 RPM you should be seeing 13.0 to 13.5", 10 sounds pretty damn low
 

Zeffer

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Dec 15, 2021
#38
  • Dec 15, 2021
  • #38
Any idea's why my vacuum would only be 10", I've confirmed I have no leaks, timing is set, rockers are set at zero lash plus 1/2 turn.
 

Boostedpimp

20+ Year Stangneter
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Dec 15, 2021
#39
  • Dec 15, 2021
  • #39
Zeffer said:
Any idea's why my vacuum would only be 10", I've confirmed I have no leaks, timing is set, rockers are set at zero lash plus 1/2 turn.
Click to expand...
What is the idle speed?

If it were me, I'd probably do a leak down test first If I was 100 percent sure their were zero vacuum leaks and I didn't use the wrong length pushrods but off the top of my head only reasons I can think of would be late ignition/valve timing, low compression, bent/damaged valves, collapsed lifter clearance to small due to wrong size pushrods or......a faulty vacuum gauge.
 

manicmechanic007

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Dec 16, 2021
#40
  • Dec 16, 2021
  • #40
One issue to think about is how tight the new motor is
Sometimes that are so tight they need to run for a few hours to break them in a bit and then they will idle
In your case You will need to do some tuning as well as get the TB leak figured out
The code reader is likely to go off like an x wife with the engine mods
 
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