Carb running rich ***update***
#465107
09/10/09 06:44 PM
09/10/09 06:44 PM
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Joined: Aug 2003
Posts: 1,247
Chi-Town
PlumCrazyCharger
OP
pro stock
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OP
pro stock
Joined: Aug 2003
Posts: 1,247
Chi-Town
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Put a more street/strip engine in the 69. 440 with sr heads, 9.5 to 1 comp, 35 degrees timing, hydralic cam 520ish lift, 3.73 gears.
Problem is it's running very rich at idle/low speed. Have a Quickfuel 750 vac secondary carb with a torker 2 intake. Primary jet is 76 and secondary jet is 78. Has a power valve, but don't know the number. Would the power valve affect the richness? I don't have an 02, but plugs are dead rich and eyes burn.
Also it gets bad mileage. Maybe 4-5 MPG cruising on the highway at 65 (~2800 RPM). I use to get that MPG with a bigger cam and dominator.
Any ideas????
Last edited by PlumCrazyCharger; 09/11/09 01:39 PM.
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Re: Carb running rich
[Re: PlumCrazyCharger]
#465108
09/10/09 07:24 PM
09/10/09 07:24 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Put a more street/strip engine in the 69. 440 with sr heads, 9.5 to 1 comp, 35 degrees timing, hydralic cam 520ish lift, 3.73 gears.
Problem is it's running very rich at idle/low speed. Have a Quickfuel 750 vac secondary carb with a torker 2 intake. Primary jet is 76 and secondary jet is 78. Has a power valve, but don't know the number. Would the power valve affect the richness? I don't have an 02, but plugs are dead rich and eyes burn.
Also it gets bad mileage. Maybe 4-5 MPG cruising on the highway at 65 (~2800 RPM). I use to get that MPG with a bigger cam and dominator.
Any ideas????
Yes the PV will effect the idle if its open already,
it would be dumping fuel.... check your vac at idle
in gear and get a PV about 2" lower than the idle
vac number..... plus your jet sizes dont jive with
running a PV... the PV side, the jets should be
8 jet sizes smaller than the non-jet side
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Re: Carb running rich
[Re: PlumCrazyCharger]
#465109
09/10/09 07:27 PM
09/10/09 07:27 PM
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Joined: Dec 2008
Posts: 1,200
UK
602heavy
pro stock
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pro stock
Joined: Dec 2008
Posts: 1,200
UK
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Power valve circuit does'nt come into play @ idle , the PV channel will only flow fuel when main metering starts , is this a new carb out the box? , is the PV gasket in tact/PV blown , is the motor idling on the mains? (trans slot too far exposed) , float level set to high? , N&S seating ok? , too much fuel pressure? , timing too far retarded @ idle? IABs blocked, pump umbrella seals?
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Re: Carb running rich
[Re: 602heavy]
#465112
09/10/09 07:38 PM
09/10/09 07:38 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Power valve circuit does'nt come into play @ idle , the PV channel will only flow fuel when main metering starts , is this a new carb out the box? , is the PV gasket in tact/PV blown
This is what I was trying to say... if its open/blown
or the transfer slot open too far
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Re: Carb running rich
[Re: MR_P_BODY]
#465113
09/10/09 07:41 PM
09/10/09 07:41 PM
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Joined: Dec 2008
Posts: 1,200
UK
602heavy
pro stock
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pro stock
Joined: Dec 2008
Posts: 1,200
UK
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Quote:
Quote:
Power valve circuit does'nt come into play @ idle , the PV channel will only flow fuel when main metering starts , is this a new carb out the box? , is the PV gasket in tact/PV blown
This is what I was trying to say... if its open/blown
or the transfer slot open too far
Mr P , i posted before i saw you're post , so was'nt disagreeing as i never read you're post anyhow.
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Re: Carb running rich
[Re: 602heavy]
#465114
09/10/09 07:45 PM
09/10/09 07:45 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Quote:
Quote:
Power valve circuit does'nt come into play @ idle , the PV channel will only flow fuel when main metering starts , is this a new carb out the box? , is the PV gasket in tact/PV blown
This is what I was trying to say... if its open/blown
or the transfer slot open too far
Mr P , i posted before i saw you're post , so was'nt disagreeing as i never read you're post anyhow.
LOL....
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Re: Carb running rich
[Re: PlumCrazyCharger]
#465116
09/10/09 10:47 PM
09/10/09 10:47 PM
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Joined: Oct 2007
Posts: 4,206
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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You need more initial spark lead to get those blades closed up and shut off the PV.
Boffin Emeritus
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Re: Carb running rich
[Re: PlumCrazyCharger]
#465118
09/11/09 02:14 PM
09/11/09 02:14 PM
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Joined: May 2004
Posts: 3,210
robin hood country
deaks
master
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master
Joined: May 2004
Posts: 3,210
robin hood country
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To my knowledge the largest bush gives 18 degrees advance, the only way i could get 10 was to use the FBO bushes.
Mick
69 Dart GTS 440 mopar .590 cam, Edelbrock heads, 3200#
best et 6.45, 106.78, 10.14, 132.88 mph, 1.47 60ft
best 60ft 1.36
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Re: Carb running rich
[Re: PlumCrazyCharger]
#465119
09/11/09 02:16 PM
09/11/09 02:16 PM
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Joined: Feb 2003
Posts: 1,572
wisconSIN
Blown61
pro stock
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pro stock
Joined: Feb 2003
Posts: 1,572
wisconSIN
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Quote:
Well found the springs for the MSD billet distributor. Never thought of that until the suggestions from you guys. I had 28 degrees retard on the distributor! Changed the bushing to only have 10 degrees and so at idle I have 24 degrees timing and 34 degrees overall. Now it idles better and not rich. As Poly said now I can back down the idle screw for and not open the power valve or jump into the main circuit.
Thanks for all the ideas!
http://www.holley.com/TechService/Library.asp
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Re: Carb running rich
[Re: PlumCrazyCharger]
#465122
09/11/09 10:51 PM
09/11/09 10:51 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Not sure about the 18 degrees. I checked my timing and it's 10 degrees diff. 24 at idle and 34 at 2000 RPM. Let you guys know on Sunday how it works!
at 2000 rpm your probably not at full advance yet. i'd check it at 3500.
also, you shouldn't need 1.5 turns out for your combo at idle on all four screws. you've made it idle better, but i bet you can still improve on that.
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Re: Carb running rich
[Re: PlumCrazyCharger]
#465124
09/12/09 10:17 PM
09/12/09 10:17 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Yes fully advanced at 1800 RPM. Wow drove to Rt.66 today and got ~14 MPG only took 4.2 gallons to go 65 miles!
that's great !!! which springs and bushing are you using in the distributor?
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