No Power

[Pete W]

I broke off fast idle cam on my Holley 1908 carb and I bought a NOS Autolight(says on the tag) Holley car to to replace it. I couldn't find the cam so I got a good deal on a whole carb. The car was running great before the cam broke so I didn't anticipate any problems. When I put the carb on I found that it needed adjustment. I tinkered with the idle screw and mixture screw and got it to start and Idle just fine. It does concern me that the mixture screw is more than three turns out and the idle screw is pegged all the way down which is not what the manual says. It does start and idle great though. My problem now is that I'm getting no power. It seems like I lost about half of the horsepower. In second gear it bogs down going up the slightest hill and takes forever to get up to speed. When it bogs down going up a holl I try to restart and it won't turn over unless I keep the accelerator pressed down. It has to be something with the new carb that's doing this. All bolts are tight so I really don't think it's a not vacuum problem(hope not) but hopefully an adjustment problem. Any idea's?

 

[66 Fastback]

What year car, engine and what kind of distributor do you have?
You might have a carb / distributor incompatibility problem.
Doug

 

[Pete W]

I have a 1961 comet with a 144, 2.77 manual 3 speed, carb with auto choke. The dizzy is your basic one that originally came with the car. I've replaced the cap, points, etc a while back. The carb looks just like my 1908 Holley, inside and out but the tag says Autolitle. The fuel bowl cover says Holley.

 

[66 Fastback]

I don't know the differences between the various carb models. But I assume that the 1908 had a spark control valve. Does your new carb have the spark control valve?
check the sticky's at the top of this section to see what the spark control valve is and what it does.
Doug

 

[Patrick66]

if its an autolite 1100 it has a scv, if its an 1101 im pretty sure it doesnt. what model is it? if your using a dist for a 61 (load o matic) then you need a carb with a spark control valve- or you need to upgrade to a 68 or later (duraspark) to use with a carb without a spark control valve.

 

[xctasy]

The carb you have is most likely the Holley 1940, a very basic 'onse size fits all' replacement for the Autolite 1100. Autolite went bust in the late 60's. The 1940 does not have an SCV valve, so yeah, your gonna have to get a later Ford points, or Duraspark I or II electronic ignition.

 

[fordconvert]

If it was truly an old stock carb its possible that the gaskets and other soft parts are shot just from old age. Also 10+ year old stuff is not going to do well with the alcohols and other stuff found in much of our modern fuels.

Messed up timing due to scv/load o issues could easily cause the same no power issue.

 

[james singleton]

Xecute, It seems that on previous posts concerning carbs there have been discussions about the 1940 carb (by Holley/Motorcraft) and other people have claimed that it does not have the SCV (spark control valve). I am pretty sure that the carb I installed on my 200cid engine way back in 1980 is a 1940 carb, and yes it does have the SCV! I still have the literature that came with the new carb and the picture in the literature shows the Model 1940 carb with a SCV. I believe that some 1940 Models have the SCV and some do not. On the Models that don't have a SCV, there is just the empty cavity there. Thought I would point that out.

 

[wallaka]

It's pretty easy to tell--is there a big gold nut-looking thing near where the vacuum line screws in? If so, that's the SCV. If it doesn't have that, then there is a mismatch.

 

[fordconvert]

They look like a Holley power valve (if you have ever had the bigger holleys apart) but on the outside instead of in the bowl.

 

[Pete W]

It has a spark control valve

 

[CZLN6]

Howdy Pete and All:

While you're checking out the SCV issue, be sure to check the linkage function. It is possible that the accelerator pedal inside the car is not getting full throttle at the carb. Check this out by having someone depress the gas pedal while you're looking at the carb linkage to make sure that you are getting full thottle.

While I have gone to great lengths to avoid the Holley 1940 service replacement carbs, I do know that they came in a variety of sizes/cfm and configurations, such as SCV/nonSCV, manual/auto choke. They were generic enough to fit replacement needs for early 60s Holley's, through 1969 Autolites. I understand there are even versions to replace the Carter YFs.

Compatibility between your carb vacuum and your distributor is critical to good performance. With a Load-O-Matic distributor this is especially true. With an early 144, you have no good options for upgrading to a later, better distributor. So getting a carb with a SCV is the way to go.

I'd resume finding a Holley 1908 for your Comet. It is a much simpler, more reliable and efficient carb then the #1940. It is cooler too. Did the original 1908 have a glass float bowl?

Adios, David

 

[Bort62]

My problem now is that I'm getting no power.

1961 comet with a 144, 2.77 manual 3 speed

I think we found the problem


Sorry, I had to do it....

 

[Pete W]

The strangest thing just happened. I used a timing light and the mark on the pulley is way, way off to the left(looking at the engine). It's no where near the the mark on the engine. I then turned the dizzy counter clockwise until I could go no further, tuned the carb and it runs like a champ now. All the power in the world and it starts right up. Something has changed somewhere and I'm not sure what it is. When the car was running great a few weeks ago the dizzy was turned about an inch clockwise from where it is now. The only thing different is that I took off the fast idle cam from the new carb and put it on the old. I'm stumped.

 

[addo]

Sure you didn't hop the plug wires one position sideways at some point?

 

[Pete W]

I don't think so but I'll check. I've heard everything from the pin in the dizzy gear shearing to the timing chain jumping.

 

[66 Fastback]

Sounds like your the outer ring of your harmonic balancer could be loose. The elastomer gets old and dried out and disbonds from the outer ring. The ring on my 66 had slipped. If that is the case, the next time you go to time the engine the timing mark may have slipped again. It could be that the last time you set the timing the mark had slipped where it was way off mark when you used it as an index and it ran poorly. This time maybe it slipped closer to the actual TDC and your timing is closer to the desired range. You may need to pull the plugs and rotate the engine to TDC on the compression stroke. Make note of which spark plug wire tower that the distributor rotor is pointing to. When it is pointing near the #1 cyl, the TDC mark should be lined up on the balancer and the #1 piston should be at the top of its travel.
If they do not line up, look into replacing the harmonic balancer. If you don't replace the balancer you will not be able to time it with a timing light and you will have to time by best idle and highest manifold vacuum.
Doug

 

[Pete W]

Hi,

Idon't think my car(1961 Comet) has a balancer. It looks like just a pulley to me. In fact it's a dual pulley because there is an aftermarket A/C unit installed. Is the balancer under the pulley?

 

[fordconvert]

The rubber part is a thin section between the hub (the center part) and the pulley. In this picture it looks like a groove. I would think the earlier ones would have had them also. They came in both single and double versions. There was also a version where the 2nd pulley bolted to the front of the single one.

The rest of the info from where the picture came from
http://www.classicinlines.com/proddetai ... D200%2DBAL