Holley 1940 problems

StarDiero75

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Hey guys.

So I have this nasty vacuum leak that I cannot find. I've replaced the manifold to spacer and spacer to cash gaskets, rebuilt the carb and yet still nothing better. I got a video of it running on YouTube under "Holley 1940 running weird"
Please help. I'm trying to ditch my 1904 and the 1940 makes the car feel like a lot more power but it just runs like crap.
Any other questions please ask

Thanks!
 
Two places 2 start:
make sure the carb 'matches' the dizzy (LOM / SCV).
See "the Handbook" or click above @ "Tech Archive" if uncertain.
(we need more details to Dx).

If all set w/above:
spray around there w/starter fluid, etc to locate vac leak.
 
chad":3vzjnzcf said:
Two places 2 start:
make sure the carb 'matches' the dizzy (LOM / SCV).
See "the Handbook" or click above @ "Tech Archive" if uncertain.
(we need more details to Dx).

If all set w/above:
spray around there w/starter fluid, etc to locate vac leak.
It's got a new HEI dizzy and the 1940 doesn't have a spark valve. I'll check with the starter fluid next.
The carb came out of the auto wreckers and I'm hoping somehow it's not damaged or warped.
 
Howdy Star;

Welcome. and more Info please. What are you working with?

The Holley #1940 can be a bugger to sort out. Do you know what the #1940 came off of?

You can buy a mechanics stephoscope over at Harbor Freight Tool. IT can really help you zero in on a vacuum leak.

Keep it coming.

Adios, David
 
stethiscope is safer if staying away frm belts & other moving parts,
take a length of garden hose & move it around w/1 hand - other end 2 ur ear...
 
What was the car running like with the original carb? I know you said that the 1940 felt like it gave you better performance. If you have an automatic transmission, have you checked your vacuum line to the vacuum modulator? Also since you have not seen the 1940 on a running engine what was the overall condition before the rebuild? Especially how was the throttle shaft clearance? Lastly did you do the carb and distributor at the same time? I know a lot of people don't like the 1940, I must be the minority as I have had great luck with mine.

Kevin
 
ags290":3litpt6e said:
What was the car running like with the original carb? I know you said that the 1940 felt like it gave you better performance. If you have an automatic transmission, have you checked your vacuum line to the vacuum modulator? Also since you have not seen the 1940 on a running engine what was the overall condition before the rebuild? Especially how was the throttle shaft clearance? Lastly did you do the carb and distributor at the same time? I know a lot of people don't like the 1940, I must be the minority as I have had great luck with mine.

Kevin
With the original carb, the holley 1904, it ran fine, no issues whatsoever.

I have the 3 speed manual in the car.

I got the 1940 out of my local auto wreckers and it was in spooky shape. I took it to a local carb guy thatg everyone trusts and even he had issues with it. The butterfly was seized real good, the idle mixture screw was broken off inside of it, the economizer was seized real good, and the check ball was also seized bad. He finally got everything fine and I found a new screw after he was able to drill the old one out.

I did the distributor months ago.

The carb feels like a good carb, real good throttle response even with a bad vacuum leak. I actually found the leak today. It was the screw. I sprayed carb cleaner around it and it started stumbling. The trick now it to find a replacement throttle body, know anyone?
 
CZLN6":2tnrxwba said:
Howdy Star;

Welcome. and more Info please. What are you working with?

The Holley #1940 can be a bugger to sort out. Do you know what the #1940 came off of?

You can buy a mechanics stephoscope over at Harbor Freight Tool. IT can really help you zero in on a vacuum leak.

Keep it coming.

Adios, David
I'm working with a 65 Ranchero with a 200, 3 spd man, 40k volt HEI distributor.

The carb was found on a 1966 or 67 mustang 200 with an auto I believe.

Mechanics stethoscope? Is it like a doctor's one?

Thanks
Ryan
 
Howdy Back Ryan:

Good going on finding the leak.

Q- "Mechanics stethoscope (stethiscope, thanks Chad)? Is it like a doctor's one?"
A- It is similar. The end, opposite from the ear pieces, is a long, slender, hollow rod, which you can insert into various areas of the engine compartment to zero in on a vacuum leak noise. The are inexpensive and easy to use. Chad's suggestion to use tubing or hose is also useable but harder to probe safely into some areas of the engine.

Keep it coming and good luck.

Adios, David
 
BTW:
I'll take the 1904 if U wanna sell it...
Zip: 01002
 
chad":3dt5xmj3 said:
BTW:
I'll take the 1904 if U wanna sell it...
Zip: 01002
Man I could never part with the 1904, I may not like using it but I can't get rid of it. It's old reliable and never fails to work, plus it's got a special story.
Once upon a time about 6 months ago, I had not a carburetor for my car. The automate 1100 was a piece of crap and another 1908 that I found had a crack in the side of the bowl from overtightening. So I went to a completely different auto wreckers and they didn't really have a bunch of old cords but they had this 1952 F1, the truck was all there! It even had the keys in the ignition, a complete time capsule. We would've bought the truck but we didn't have the money, it was beautiful. Also it had what we were looking for, a 1904. So we took it off and gave it a quick cleaning, it was actually pretty clean; I probably could have slapped it on my car and it would've worked. We swapped all the gaskets off the toast 1908 and put them on the 1904 and off we went. The Ranchero started right up and that's how it's been ever since. A few weeks after this my dad and I called back to the auto wreckers to inquire about the F1, they had disassembled and parted the whole thing out. It was a perfect complete truck!!!! So the 1904 is a reminder to my dad and I of a real neat truck that didn't deserve to die.
The end.
 
ags290":6yp0wtxk said:
What was the car running like with the original carb? I know you said that the 1940 felt like it gave you better performance. If you have an automatic transmission, have you checked your vacuum line to the vacuum modulator? Also since you have not seen the 1940 on a running engine what was the overall condition before the rebuild? Especially how was the throttle shaft clearance? Lastly did you do the carb and distributor at the same time? I know a lot of people don't like the 1940, I must be the minority as I have had great luck with mine.

Kevin
You wouldn't happen to know someone with a 1940 they're parting out Or selling, would you? I gotta find a throttle body but everyone wants way too much for the carb in general.
 
our "4 sale"?
BTW: nice story (altho a horror based 1...reminds me of the nightmares I had during: 'Cash 4 Crushers' or whatever it wuz)
 
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