| Q. for Larry W. [message #91269] |
Tue, 06 July 2010 13:13  |
g.winger
Messages: 792
Registered: February 2008
Location: Warrenton,Missouri
Karma: 0
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Larry,ITS RUNNIN!!!, a little rich. Was wondering what jets, pri. rods and sec. rods you are running??? Also,,,hows the hot fuel injection workin so far??? Finished for Duquoin??,,thanks,,PL
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| Re: Q. for Larry W. [message #91307 is a reply to message #91269] |
Tue, 06 July 2010 18:24  |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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| g.winger wrote on Tue, 06 July 2010 13:13 |
Larry,ITS RUNNIN!!!, a little rich. Was wondering what jets, pri. rods and sec. rods you are running??? Also,,,hows the hot fuel injection workin so far??? Finished for Duquoin??,,thanks,,PL
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Hey paul,
Glad to hear it is running. So far what I have is .074 primary jets, 50D primary rods (.036 tip), Red power piston spring (8-4), CJ rods in Secondarys (same as GMCMH rods), and 1 turn wind-up on the secondary flap.
I'm still running a little rich at lean cruise (14.7 to 15.3/1) and getting a little hesitation when putting my foot in it to WOT. (AF goes to 17-18/1 briefly) Tomorrow I am going to try a set of .073 in the primary, and tighten up the flap another 1/4 turn. I'm also using a early 80's truck Q-jet that has an adjustable APT (adjustable part throttle). This one is adjustable both for how deep the rod goes into the jet and adjustable for how far the rod comes out of the jet. Allowing a fine tuning (so to speak) of the AF at both cruise and WOT. This set-up is also pretty cold blooded during warm-up, and gets worse as I jet leaner. Gotta figure out what I'm gonna do there...or maybe just put up with it until the FI is installed.
As for the FI, I'm waiting for the EBL Flash to be developed for the 7730 ECU. Hopefully it will be here by sometime this fall.
Just a side note, I had tuned the carb at around 15/1 or so cruise before I left for the south last winter. By the time I got to Florida, it was running in the mid 14/1 range.
By the time I got home it was running in the 13's, yet I did nothing to the carb to make it change. Looked at lots of reasons and non panned out. Finally checked the air filter. While it passed the visual inspection (holding a light to the inside of it) I decided to replace it anyway. AF went back to 15/1....JUST LIKE THAT!! Lesson???? KISS.
Larry 
78 Royale w/500 Caddy
Menomonie, WI.
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| Re: Q. for Larry W. [message #91310 is a reply to message #91309] |
Tue, 06 July 2010 18:45 |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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It is from a early 80's truck. The APT adjustment is located center of the carb just a *little* forward of the aircleaner gasket and directly in front of the vent tube. It is right next to the air cleaner gasket surface. There is plug in the hole that has to be punched out from the under side of the carb top housing. On mine there are two adjustments. A special tool reaches down through the hole to a screw adjustment that adjust the bottoming of the power piston, and in turn the rods, placement within the jet. Since the jet is say .074, and the rod is .050 at the fattest point, and tapered down to .036 at the narrowest point. the APT can hold the rod from going all of the way into the jet...at say the point on the taper that is .046, allowing a richer mixture than if it were all of the way down in the jet at the .050 spot. When the vacuum is low, and the spring pushes the rod out of the jet, another adjustment at the top of the rod holder, stops the rod from coming all of the way out of the taper...say...stopping at the .038 spot, therefore making it leaner than if the rod were all of the way out at the .036 tip. Is this making sense?
Larry
78 Royale w/500 Caddy
Menomonie, WI.
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