Holley 1850 carb question
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,241
Likes: 4
From: Okinawa Okinawa
Holley 1850 carb question
If you have been following my posts on my carb trouble I just about have it correct.
I have went from 13 to 17 inches of vacum from adjusting the timing and the idle. I have a slight hesitation if I hit the gas at a dead stop. If I start off slowly to about 1500 RMP then I can hit the gas and no problem. I am going to adjust the float on it this weekend and see if that helps. If anyone knows how to do this with a 1850 please let me know.
I took it out on the interstate tonight and gave it a little spin. It is running good except when I am accelorating it starts to stall out at about 70 mph. It did this before my top end rebuild. The car basically set still for 6 months when I was in Afghanistan. It acts like I have a rev limiter on it. My wife started the car during my deployment about once a week. Any thoughts on this?
I have went from 13 to 17 inches of vacum from adjusting the timing and the idle. I have a slight hesitation if I hit the gas at a dead stop. If I start off slowly to about 1500 RMP then I can hit the gas and no problem. I am going to adjust the float on it this weekend and see if that helps. If anyone knows how to do this with a 1850 please let me know.
I took it out on the interstate tonight and gave it a little spin. It is running good except when I am accelorating it starts to stall out at about 70 mph. It did this before my top end rebuild. The car basically set still for 6 months when I was in Afghanistan. It acts like I have a rev limiter on it. My wife started the car during my deployment about once a week. Any thoughts on this?
Burning Brakes
Joined: Apr 2001
Posts: 752
Likes: 1
From: Springfield Oregon
Re: Holley 1850 carb question (scottw)
Check out this tuning paper by Lars
https://www.corvetteforum.com/techti...=108&TopicID=3
https://www.corvetteforum.com/techti...=108&TopicID=3
Racer
Joined: May 2000
Posts: 386
Likes: 0
From: Niedernhausen, Germany
Re: Holley 1850 carb question (ORVette)
Hesitation on start: Accelerator pump puts in too little (or nothing) or too much. Check the pump-diaphragma at the bottom of the front fuel bowl.
After 70mph: Check the fuel pump - sounds like it delivers not enough fuel for higher speeds.
Regards,
Thomas
After 70mph: Check the fuel pump - sounds like it delivers not enough fuel for higher speeds.
Regards,
Thomas
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,241
Likes: 4
From: Okinawa Okinawa
Re: Holley 1850 carb question (V8yunkie)
I have lars paper and this weekend I am going to adjust the float and everything else.
I don't think it is the fuel pump after 70 because it did it before my top end rebuild and I changed fuel pumps during the rebuild??
If it doesn't stop after adjusting the carb I'll check on the fuel pump. How do you check to see if it is working right?
How do you check the pump diaphram on the acc pump? Never worked with carbs before.
I don't think it is the fuel pump after 70 because it did it before my top end rebuild and I changed fuel pumps during the rebuild??
If it doesn't stop after adjusting the carb I'll check on the fuel pump. How do you check to see if it is working right?
How do you check the pump diaphram on the acc pump? Never worked with carbs before.
Le Mans Master
Joined: Aug 2000
Posts: 6,362
Likes: 7
From: Brazos TX
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Holley 1850 carb question (scottw)
Check the accl. pump diaphram by visually determining that it isn't leaking and that it is squirting fuel into the carb when the throttle is moved from closed to open. Do this with the engine off. If it isn't squirting immediatedly upon throttle movement then the accl. pump arm must be adjusted so that it contacts the other linkage properly. You can try changing the positon of the accl. pump cam on the throttle shaft. There are two positions that the plastic cam can be installed at. Switching to the other position is worth a try.
Check this out on Holley's web site http://www.holley.com/HiOctn/TechSer...fo/TI-221.html http://www.holley.com/HiOctn/TechSer...o/FMCTech.html http://www.holley.com/HiOctn/TechSer.../Instruct.html
Keep this in mind when you are adjusting the accl. pump. Always check this after making adjustments to the linkage
An 1850 is a 4160 style carb.
Check this out on Holley's web site http://www.holley.com/HiOctn/TechSer...fo/TI-221.html http://www.holley.com/HiOctn/TechSer...o/FMCTech.html http://www.holley.com/HiOctn/TechSer.../Instruct.html
Keep this in mind when you are adjusting the accl. pump. Always check this after making adjustments to the linkage
An 1850 is a 4160 style carb.
Instructor
Joined: Nov 2001
Posts: 175
Likes: 0
From: St Louis MO
Re: Holley 1850 carb question (scottw)
I would suggest buying those clear sight plugs for the float bowls because if you are not very careful when adjusting the float levels, gas can pour out the sight holes and onto the hot manifold. They are only a few bucks. To check the accelerator pump just look into the primary bores and move the throttle and you should see a shot of gas go into the carb, and you don't need the car running for this. Another thing you might check is that the fuel line from the frame to the fuel pump is not restricted, especially if it has one of those "S" formed hoses and it has been replaced with a normal hose and is resrticted in the bend. Hope this helps. :chevy
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,241
Likes: 4
From: Okinawa Okinawa
Re: Holley 1850 carb question (yogi78)
I just got done adjusting the float and everything else on lars carb paper. Unfortunately I didn't see the loosen the screw and I almost took it all the way off then I got a few good pumps of fuel all over the place. As long as it didn't catch on fire.. good learning point. Bet I never do that again :rolleyes:
I can't road test because its raining. Try tomorrow. Also, I noticed that the shot of fuel stops just before WOT. Isn't it suppose to be continuous?? Do I need to consider changing to a bigger size?
I need to check the hose because it is a normal hose and not the S hose.
Thanks for all the info.
I can't road test because its raining. Try tomorrow. Also, I noticed that the shot of fuel stops just before WOT. Isn't it suppose to be continuous?? Do I need to consider changing to a bigger size?
I need to check the hose because it is a normal hose and not the S hose.
Thanks for all the info.
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1st Gear
Joined: Dec 2001
Posts: 1
Likes: 0
Re: Holley 1850 carb question (scottw)
I have an idea for you. The problem with the dead spot is the acceloratop pump SHOOTER. Look inside the choke area, see the little thing with two little nozzles. You need a bigger one. A 35 works fine. As for the top end, the 1850 is the most over rated carb on the market. I have had several, and all have been crap. They work but not well at all. The best carb for the street to me is the 3310 holley. Get one off ebay and I will help tune it with you. Made a killer difference on my Corvette. thinsg to change on it too. Vac. Sec. and will tell you the tricks to come in smooth and strong...i.e. done my dyno time. Mail me... mrjata@hotmail.com :yesnod:
