Trouble Shooting Holley 4150
#513824
11/01/09 11:29 PM
11/01/09 11:29 PM
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Joined: Jun 2006
Posts: 5,159
CT
GTX MATT
OP
master
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OP
master
Joined: Jun 2006
Posts: 5,159
CT
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Ive got a Holley 4150 that was original equiptment on a Chrysler. Its 600 CFM.
On my 440 it seems to have a fuel supply issue. It starts easy and as it should, but it idles pretty rough. Once you give it gas it starts to increase in RPM normally until about 1300 rpm, after that youre giving it alot more for just a slight gain in RPM, and at about 3/4 throttle and 2000 RPM it wants to die. It will not rev above 2000 rpm, even if you increase throttle slowly. It also revs up pretty rough and occasionally pops through the carb.
I tried this carb on a Ford 302 and it did the same thing, other than alowing it to rev up normally but still slightly rough.
I took it apart, and it looks recently rebuilt. All of the gaskets came off easy without scraping, looked new, floats look new and dont have holes, needle and seat look good, all passages clear, floats were set correctly. Im at a loss.
Im thinking maybe a bad power valve. Any ideas?
Last edited by GTX MATT; 11/02/09 02:40 PM.
Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street
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Re: Trouble Shooting Holley 1850
[Re: GTX MATT]
#513825
11/02/09 12:45 AM
11/02/09 12:45 AM
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Joined: Jan 2003
Posts: 1,263
Southwestern Ontario Canada
racealittle
pro stock
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pro stock
Joined: Jan 2003
Posts: 1,263
Southwestern Ontario Canada
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Are you sure you have enough pump shot?
Is it adjusted properly? Is the shooter large enough?
Too many cars, too many parts, too little coin, too little space to work in, too little time left to make it all happen!
Update: down to one ride, still too many parts, a little more jingle in the pocket, gaining space, and it's going to happen this year!
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Re: Trouble Shooting Holley 1850
[Re: B5 Bee]
#513829
11/02/09 12:16 PM
11/02/09 12:16 PM
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Joined: Jun 2006
Posts: 5,159
CT
GTX MATT
OP
master
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OP
master
Joined: Jun 2006
Posts: 5,159
CT
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Needle and seat look brand new, accelerator pump shot is great.
It is an OEM Chrysler carb, the list number is 4749 or something like that, and it doesnt have externally adjustable floats. I just had a brainfart when posting originally and typed 1850 instead of 4150.
I thought it seemed lean too but it does smell kind of rich. Not smoking much though.
Ill see if gaskets are blocking anything.
Any idea where I can find a rebuild kit for this? Should a typical 4150 rebuild kit have the necessary parts? I cant find the list number on summit to order a kit.
Last edited by GTX MATT; 11/02/09 01:43 PM.
Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street
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Re: Trouble Shooting Holley 1850
[Re: GTX MATT]
#513830
11/02/09 01:11 PM
11/02/09 01:11 PM
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Joined: Mar 2005
Posts: 1,373
Rancho Cucamonga, CA
D_C
pro stock
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pro stock
Joined: Mar 2005
Posts: 1,373
Rancho Cucamonga, CA
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Some good advice above. You could always try a New Power-Valve, but I doubt that is the problem. It could be a bad gasket (like the baseplate-to-body) or a cracked baseplate. If it has Internally-adjustable floats, have you checked the adjustment height? It may be suffering from low fuel level. That can cause problems as you describe. Holley has lots and lots of great, FREE information at their website including instructional videos. Holley Tech Library Holley TV and Videos You can also search YouTube for videos on Holley carb topics. If all else fails, you could seek out a local performance-oriented carburetor repair/tuning shop, or worst case, buy a replacement carb. Carb problems can be frustrating. Sometimes, there is more than one problem involved.
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Re: Trouble Shooting Holley 1850
[Re: D_C]
#513831
11/02/09 03:18 PM
11/02/09 03:18 PM
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Joined: Sep 2005
Posts: 6,516
Santa Cruz, California
Lefty
master
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master
Joined: Sep 2005
Posts: 6,516
Santa Cruz, California
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Quote:
Most rebuild kits come with an assortment of gaskets so one kit will do a multitude of 4150/4160 Holleys.
Some one may have done a poor job of matching up the gaskets.
Take it apart and see if any of the passages are being blocked.
 The kit comes with two body gaskets, maybe the re builder installed the wrong one. 
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Re: Trouble Shooting Holley 1850
[Re: GTX MATT]
#513835
11/02/09 05:41 PM
11/02/09 05:41 PM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
mopar
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mopar
Joined: Jul 2007
Posts: 531
Virginia
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It sounds like the idle/transfer system is at least partially working, but the main circuit is not.
Do the idle mixture screws have any effect? If so, that tells you the idle system is working.
Take the primary side of the carb apart and remove the jets and power valve. Spray some carb cleaner through the jet holes, watching where the spray comes out the other side of the metering block. Then, blast it really good in the opposite direction. Spray the Power valve Channel Restrictions out, too. These are the 2 small holes exposed when the PV is removed.
In the main body, find the passage that lines up with the output of the main well passage in the metering block, and spray it. Carb cleaner should come out the boosters.
Hold the metering block tightly to the carb body (gasket in place) and spray cleaner into the jet holes. The carb spray should exit the boosters.
This proceedure should thoroughly test the main system from blockage, including a mismatched block gasket.
Jim
Last edited by JimG; 11/02/09 05:42 PM.
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Re: Trouble Shooting Holley 1850
[Re: JimG]
#513836
11/03/09 01:21 PM
11/03/09 01:21 PM
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Joined: Jun 2006
Posts: 5,159
CT
GTX MATT
OP
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OP
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Joined: Jun 2006
Posts: 5,159
CT
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Put the carb back together, put it on, it ran the same. I turned the mixture screws all the way in and it immediately idled much better. Its much more responsive, will handle full throttle and will rev clean to 2500 rpm or so, after that it pops through the carb and backfires through the exhaust.
It did run REALLY rich on the 302, but not too much on the 440.
I picked up a power valve, gonna put it in tonight after class. Cross your fingers for me.
Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street
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Re: Trouble Shooting Holley 1850
[Re: GTX MATT]
#513838
11/03/09 06:01 PM
11/03/09 06:01 PM
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Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
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Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
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having had a good running ford engine to test the carb and the problem followed the carb, it's probably a safe bet that the problem is with the carb only.
but...just to be sure you're not fighting 2 problems at once...do you have another carb you can put on the 440 to see if the 440 will run on it's own?
**Photobucket sucks**
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Re: Trouble Shooting Holley 1850
[Re: GTX MATT]
#513839
11/04/09 07:51 AM
11/04/09 07:51 AM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
mopar
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mopar
Joined: Jul 2007
Posts: 531
Virginia
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Quote:
I turned the mixture screws all the way in and it immediately idled much better.
Some of those OEM Holleys had reverse idle mixture screws, as I recall. Buried somewhere around here I might have the info if it would help you. Since the engine likes the screws turned all the way in, it would be good to know what "all the way in" actually was.
Jim
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? At what vac level does it act up "after that". We are getting closer, gonna be interesting to see what the right PV does 
. Keep us posted. EDIT is the PV open or closed when it acts up?