Slant Six Forum :: Carb trouble

Hey guys
I didn't really want to post another thread but Im having trouble with my carb. Holley 1945. I just rebuilt it this morning. I had to adjust the mixture screw quite a bit just so it'd run because it would sputter and die shortly after starting. Timing is dead on 12*. Curb idle screw has it at about 800rpm. It idles fine now but when I go to drive it has no power what so ever and when I slowly rev it it has trouble between 1k and 1400. Any help??? Also when turning the mixture screw counterclockwise it idles better the more I turn it in the rougher it gets(and it was really far in to start!) which way makes it lean and which way makes it rich. It was really rich to start it doesn't smell rich anymore. But it does smell different.

Help is appreciated as always
Thanks guys
Cody
Ps it's kinda urgent, I have school tomorrow.

Author:	Ross [ Sun May 08, 2011 3:52 pm ]
Post subject:	Carb trouble
Hey guys I didn't really want to post another thread but I'm having trouble with my carb. Holley 1945. I just rebuilt it this morning. I had to adjust the mixture screw quite a bit just so it'd run because it would sputter and die shortly after starting. Timing is dead on 12*. Curb idle screw has it at about 800rpm. It idles fine now but when I go to drive it has no power whatsoever and when I slowly rev it, it has trouble between 1k and 1400. Any help??? Also, when turning the mixture screw counterclockwise, it idles better. The more I turn it in the rougher it gets (and it was really far in to start!) Which way makes it lean and which way makes it rich? It was really rich to start. It doesn't smell rich anymore, but it does smell different. Help is appreciated as always Thanks guys Cody Ps it's kinda urgent, I have school tomorrow.

Author:	AHamilton [ Sun May 08, 2011 4:13 pm ]
Post subject:
screw them in until the engine stumbles then unscrew a half turn. A vacuum gauge and tach is helpful when performing this tune.

Author:	Mroldfart2u [ Sun May 08, 2011 4:18 pm ]
Post subject:	Re: Carb trouble
Quote: Hey guys I didn't really want to post another thread but Im having trouble with my carb. Holley 1945. I just rebuilt it this morning. I had to adjust the mixture screw quite a bit just so it'd run because it would sputter and die shortly after starting. Timing is dead on 12*. Curb idle screw has it at about 800rpm. It idles fine now but when I go to drive it has no power what so ever and when I slowly rev it it has trouble between 1k and 1400. Any help??? Also when turning the mixture screw counterclockwise it idles better the more I turn it in the rougher it gets(and it was really far in to start!) which way makes it lean and which way makes it rich. It was really rich to start it doesn't smell rich anymore. But it does smell different. Help is appreciated as always Thanks guys Cody Ps it's kinda urgent, I have school tomorrow. IN is leaner, Out is richer. I would look for a vacuum leak... maybe the carb to manifold gasket, or one of the vacuum hoses. After moving old hoses around who knows where/if the hoses will split/crack. You can use a vacuum gauge to set mixture with.

Author:	SlantSixDan [ Sun May 08, 2011 4:52 pm ]
Post subject:
Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

Author:	4speed [ Sun May 08, 2011 5:09 pm ]
Post subject:
My bet is the float level is set to low.

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Carb trouble https://slantsix.org/forum/viewtopic.php?t=44887	Page 1 of 2

Author:	Ross [ Sun May 08, 2011 5:21 pm ]
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Dang thinks for the help guys. Most of my vac hoses are new. I'll have to get a vac gauge. If out is rich then it's running very rich. Could it be that it's not getting enough fuel at idle and not enough air when I give it throttle?

Author:	Ross [ Sun May 08, 2011 5:37 pm ]
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Oh also I took the jet out to see the size it said 66 on the side. Is that too big or too small or just right?

Author:	Ross [ Sun May 08, 2011 6:44 pm ]
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So I went to dinner and come back to finish tuning and it wouldn't even idle. It'll idle at curb idle the exhaust kinda sounds like a v8 with a big cam it lopes. I have a stock cam though. Also there is a hissing noise in the carb when the throttle is opened about 1/4. And I can't drive it anywhere cuz it'll die without constant fuel I can't even set th screw cuz it won't idle at curb idle.

Author:	ceej [ Sun May 08, 2011 7:11 pm ]
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Double check your jet size. If it really is a 66, that's too large. I think a 56 or 57 would be right for the 1945. Can't remember what I had in my 1945. Somebody should chime in pretty soon with the appropriate jet size though. 2Â¢ CJ

Author:	Ross [ Sun May 08, 2011 7:35 pm ]
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Well I read your post just in time cj. I just took the carb off the truck, again, for the fourth time today to go over ALL the measurements again. Took the jet out it's either 66 or 99. Lol

Author:	DusterIdiot [ Sun May 08, 2011 7:39 pm ]
Post subject:	Did you...
Quote: I think a 56 or 57 would be right for the 1945. Can't remember what I had in my 1945. Somebody should chime in pretty soon with the appropriate jet size though. #58 in 1974 Holley 1945...1976-1979 unmolested stock carbs have a #61 in cars anyway. If your engine was a pre-81 I'd swear it needed to valve lash to be loosened up... I'm thinking vacc. leak somewhere (maybe base of the carb body? or a loose connection at the carb?) -D.Idiot

Author:	Ross [ Sun May 08, 2011 8:09 pm ]
Post subject:
Ok I'll replace the carb gasket. I have three new ones. I got two cuz I have a one inch carb spacer but got the wrong studs. I'll put the one one that came with the rebuild kit. Just adjusted the float it was a tad low just a tad so I pulled it up. Rechecked the accel pump rod it was a little too short so I opened it a little. Checked high idle cam. Gonna put her back on now and pray she runs fine with a little mixture and idle tuning. I sprayed a little carb cleaner in there too.

Author:	Ross [ Sun May 08, 2011 9:06 pm ]
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Ok so I got it running again. I looked down the carb when giving it throttle and noticed that the fuel comes out of the little shower head in little bursts, like there are air bubbles in it.

Author:	ceej [ Sun May 08, 2011 9:33 pm ]
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That's the accelerator pump, and normal operation. Install the jet Duster Idiot suggested. That should get you in the ball park. CJ

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Author:	Ross [ Sun May 08, 2011 10:39 pm ]
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Wait the fuel from the accelerator pump is supposed to come out of the shower head? Cuz it's coming out of the little hole in the wall of the venturie or whatever. Could the crappy idle be from the egr valve being open or manifold leak like at the manifold bolts? The carb nuts are as tight as they're gonna get. It's weird it'll idle at high idle but once I take it off it sputters and dies.