50 flatty idles well revs okay, but will not drive down the road.
 

I have a rebuilt 50 flatty with a 97 holley/ford 3 spd tranny. all new and rebuilt, will idle well and sounds good except for a bit of a stutter when you hit the throttle. I get it on the road and it cant handle the load and coughs and stutters and dies. it will always start back up but not quickly. dont know if it is timing or carburation. i have an electric fuel pump from napa, and an in line regulator on full flow (5). any ideas why it will not get going down the road?

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

I'm still a Flathead rookie, but I've already learned firsthand that the power valve in the typical carb kit can mess you up. And I've also learned not to trust NAPA's cheap electric pumps.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Sounds like fuel delivery. The electric pump will not make up for a clogged line/dirty tank etc. It doesn't take a big stream of fuel to idle well. My .02

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Start by using the choke a little, will tell you if it´s starved on fuel.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

"97 Holley"? Does your car have the stock "Load-a-matic" distributor? Unless you have a special version of the 97 that has provision for providing the proper venturi vacuum signal required by the stock distributor, you will have this kind of problem. We need to know exactly what you are running to be able to give you the proper advice. A regular Stromberg 97 won't have provision for the required vacuum signal for the stock distributor to function properly and the special versions that do are few and far between.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Second thoughts. I'll defer.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

twc,
A clogged air filter can cause your problem as well, remove the filter and give it
a whirl.
Charlie ny

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

The symptoms you described could also be the coil. My 51 flathead was running and driving...but not good. I was convinced it was fuel vapor lock. It turned out to simply be a bad ignition coil. A new $20 coil fixed it.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

It could be a bad rotor or cap. If the running gets progressively worse, they might be the cause.

Mart.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

With all due respect to those offering solutions, I think it is irresponsible to offer up all of this advice when we don't really have any idea of the configuration of his engine. So far I have heard "coil", "cap and rotor", "fuel pump", "air filter" and "power valve". We don't know what he is running for a distributor and especially a carburetor. I'll put this as gently as I can : someone who comes on here for his first post and says he is running a "97 Holley" is probably not the most experienced car enthusiast out there. I expect that he is running something close, if not exactly like, a completely stock configuration, but until we know for sure, throwing out possible solutions is pissing into the wind.

To the original poster : please come back and give us as much detailed information as you can about your engine. Is it a stock distributor or aftermarket? What numbers are on the carburetor; has the engine been modified during the rebuild? Knowledge is power.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Lot's of good info already given. I would start by using the choke as suggested.
You should not need more than 2# of fuel pressure, ain't right... Chap

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

this is my first concern with his post....



IF he has a 97 and has connected the original ignition to manifold vacuum there will be problems. IF that is the case, plug the vacuum line and set the timing to about 14 or so degrees and take it for a spin. if its better we know the problem. loadamatics will not advance without vacuum.



IF it's not a 97/loadamatic issue my 8ba did exactly the same thing. it had two problems. bad fuel pump which led to ignition being left on which completely fried the ignition system. once I swapped the pump my symptoms were the same as yours. needed a new coil, condensor and points.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

New member, as stated above knowing what you have exactly is key to finding the problem. There are MANY things it could be but probably only 1 or maybe 2 things it actually is. Can you take a picture of the engine showing the carb, intake, manifold and distributor? Posting pictures is a challenge for some folks but there are instructions.
And welcome! Don't get discouraged.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Tub and Deuce are right need more info and pic will help greatly.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

It could even be the wrong 94?? Tubman has it,

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Has it always been this way or has it just happened? if just happened then recheck what you may have been "fine tuning" lately. Just a thought.
Phil NZ

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

wow guys, amazing response and thanks for the help and suggestions. its an 8ba recently rebuilt, stock distributor, new cap, vac advance, bug from Macs, coil is a flametrower, carb has ford script and 8ba on the side with AA-1 on the base, used a holley AA-1 kit. went thru 2 power valves, both leaked the bowl dry. third time it held and is running better. Tubman, I am a dire enthusiast but not that experienced with the nomenclature but will work on that.

It is in a 47 truck, bought when I was 15, 38 years ago. drove the heck out of it when a teenager then life crept up, wife, 4 kids, 4 states, 5 houses....kept the truck all these years and started the process last year. rebuilt the 50 8BA block, bored 60 over due to cylinder issues. just trying to get it back on the road now that I am 53 and becoming an empty nester. no charge for the history.

I think it is fuel delivery. the electric fuel pump and regulator are old and the fuel filter could be restrictive. I will straight plumb it and see. took the air filter off and it didn't help. advanced and retarded the timing on the road to no avail. I will try the fuel and let everyone know. thanks for all the suggestion, you guys are great. tried to attach photos but "security token was missing", not sure what that means. will try again.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Thanks for getting back to us. The additional information is quite helpful. It sounds like you have the proper carburetor for the Load-a-matic (stock distributor). One thing to confirm; does it have the proper vacuum line that runs from the middle back of the carburetor to the distributor? This line is necessary for the system to function properly.

That being said, from what you are telling us, it sounds like a fuel problem. You say the carburetor was rebuilt; did you do it yourself or send it to a reputable rebuilder? Again, I hate to be critical, but the first carburetor I rebuilt myself would not even run on the car. It took me two or three tries to get it even close. If you are not absolutely certain of the carburetor, it might be a good idea to send it out to be redone. There are guys on here ("charlieNY" and "Sciala" come to mind) who are experts on these carburetors and can guarantee one that performs properly. I think you are on the right track with replacing the old components in the fuel system. If it were me, I'd start with a stock system with a known good mechanical pump and worrying about an electric later. One thing that hasn't been mentioned is the fuel tank and lines; are you sure they are clean and in good condition? Perhaps trying to run it from a temporary tank may help if the original system is suspect.

Keep at it; I'm sure you'll get it and will be able to enjoy the truck like you did back in the day, probably even more. I had a carburetor problem (caused by a shoddy previous rebuild) that took me a year to chase down completely. One last thing; you should post your location so we know where you are. There may be someone close who has a good carburetor you could swap in temporarily, which is probably the easiest way to isolate problems like this.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

Still think you should start with the basic tests.
Pull the chike a bit and see if it runs.
If so that means you have fuel coming to the carburetor and the mixture is bad.
If it doesn´t run better on choke you have to investigate fuelpump lines filter...non vented fuelcap...
That would narrow it down a bit.

Re: 50 flatty idles well revs okay, but will not drive down the road.
 

I'd like to throw a monkey wrench in. While it does sound like fuel delivery, I've seen similar symptoms with mismatched coil/resistors (i.e. having an external resistor, and an internally resisted coil).