Technical Flathead Starting/Idle Problems

Hey There...

I have 41 Super Deluxe 2bbl, v8, completely stock. I purchased the car which had been sitting for several years. I have gotten it running and have been whack-a-moling gremlins for the past several months. My issue at hand is with starting idle. I can get the car to start with the choke pulled about 1/4 pull out, and eventually ease it in. the car will idle somewhat. if i feather the gas the car will rev. if i push the pedal to the floor the car stalls. If i mash it real quick...it hesitates and sometime backfires out the carb. Last time it shot a good flame. I can drive the car, but only with the coke pulled out, it runs like crap with it pushed all the way in. To muddy the waters further i recently replaced the vacuum brake being the one in the car was completely missing the leather and the car was whistling. Although i could be incorrect, i thought that part didn't matter until i was in the 30mph+ range. I really appreciate everyone's help.

 

It sounds like a carburetor problem, so that means it's probably an ignition problem. You said you replaced the vacuum brake plunger. Did you do anything else to the distributor? Did you take it off and see if it was corroded or fuzzy inside. Might want to do that and just give the points a very light swipe with a point file to remove any corrosion from the storage period. Not enough to remove contact material, but just clean them off. A good parts store will have a special file for points. A teeenage clerk will ask what points are, so walk up to the oldest clerk you can find.

Also see if the rest of the internals like the advance, rotor, inner caps, and such seem to be clean and not gummed or sticking.

When it is running fine again, you adjust the vac brake by running along about 20 miles per hour and then stomp on it. If it rattles/pings you crank the adjuster bolt inward a half turn and try again. Continue as needed. When it stops rattling/pinging, tighten the locknut.

 

It won’t run unless the choke is pulled out ?
Sounds like a dirty /stopped up carb,,,,you did say it had been sitting for some time .
That is one direction to look in .

Tommy

 

Thanks for the reply. I will look into that tomorrow. I do have a spare distributor is necessary. Car came with lots of spare parts. Ill open it up and take some pics.

 

I considered replacing it, and i do have another (condition unknown came with the car). I have already drained the tank, opened up the fuel filter and cleaned it out. Car has had a recent oil change, plugs as well. I have the two back screws reset to 1.5 turns maybe 1.75 and the throttle screw about midway. I have the pin in the linkage on the lowest hole since i live in FL and the book i have ( car came with a box of books) xtated that hold was for "summer" as it always is here....

 

You need to remove that carburetor, clean and rebuild it. When a car sits for a long time, the carburetor gets gummed up. Also check to make sure there is no rust coming through from the tank. Another problem that occurs when the car sits for a while.

 

Like others have said, if pulling out the choke makes it run better, you have a lean problem. It also sounds like the accelerator pump in the carburetor isn't working. If you look down the carb throat with the engine NOT running, can you see a squirt of gas when you open the throttle? If you don't the accelerator pump has failed. That will make it hesitate on acceleration and/or backfire through the carb. Time for a carb tear down and rebuild.

 

Sounds like time to rebuild the carb. The leathers in the pumps could have dried up.
What type of carb ? If a 94 holley, what is the condition of the power valve ?

 

Along with a carb rebuild. Pull your fuel tank and have it cleaned.
Odds are you’ll fill that rebuilt carb with junk again.
A backfire through the carb will ruin the power valve in a heartbeat.
Need a good rebuilder?
Two Hamber’s.

http://vintagespeed.com/

Or


http://dickshotrodcarbs.com/dickyorktestimonials.html

 

I have tried that and it squirts, but honestly, the stream doesn't look to strong to me, compared to a higher end Holley 4bbl.

 

Hi guys. Thank you for all the responses. I'm going to try and take a look at the dist. today if i can. I do have another carb in a box somewhere in my pile of parts. So do you think its worth it to switch them out? I am unsure of its status...
I did drain the fuel out of the tank with my father when we started working on the car, but i recall aside from the smell it was clean. This was was a nut & bolt frame off job when it was put together 10 or so years ago. So i'm assuming the tank was new...

 

Now you’ve had three or four guys tell you to rebuild your carb. Why do you again ask about installing an unknown carb?
You know the first three letters of assume means, clean your tank out.

 

Sounds like it is a really nice car,,,should be in good shape.
It is a good idea to check the distributor,,,I don’t know what you will find.
If the vacuum is leaking on the distributor,,,that might explain your choke pulling.
From your description,,,,,I believe you will end back up at the carb.
Good luck man,,,,tell us what it turns out to be .

Tommy

 

lol...understood....

 

That vintage speed place is only about an hour and a half north of me...maybe ill take a ride there this week.

 

Since you are new here I'd recommend doing a search about Vintage Speed before you give them parts or money. Lots of people have "opinions" about them.

 

Ty. Will defintely take that into consideration.

 

I had a similar problem with the 48 Ford I bought last year. It had sat for several years. I had to replace the gas tank, fuel lines to the engine and fuel pump because of old gas residue and shellac like coating. It still didn't run good so I sent my carb off to CharlieNY over on the Fordbarn. I bolted it on and it ran perfectly out of the box from the get go. He made it like a new one. Cranks instantly and idles smooth as a baby's butt.

 

Morning. guys. Ty for all your input. I cleaned inside the dist. and lightly sanded the contacts on the end of the spark wires in there, and there was some improvement. Still working on carb. res. and fuel.

 

Good morning. My apologies for the delay in a follow-up. Between work and family, my schedule is tight . I bought a new carb. Installed it. Car wont start. I'm getting fuel. So if i have air and fuel, figured i'm not getting spark. Put my battery on the tender all night. Checked again this morning. No go. Put my battery tester on the battery and it failed. Problem there is that this battery is maybe 30 days old...cause the last one died in 90 days. First time i assumed the battery...(i have that kind of luck)...but twice...its the car. So the coil is new, the condenser is new-ish (replaced in the last 6 months), the Solenoid is new. Only major electrical component i have not replaced the generator and the regulator. Any suggestions on figuring out what may be killing my battery?

 

If I remember this right, you disconnect the negative terminal from the battery post and place an ammeter between the negative battery post and a good ground on the frame ( assuming you are neg. ground). The ammeter should read zero if everything is turned off. If it doesn't read zero, then you pull fuses one at a time until it reads zero. That fuse will tell you which circuit is drawing current.

 

I agree. I am familiar with that method and was going to try and take a look today. Problem is that I don't believe there are fuses in that car....

 

Sounds like the idle circuit has trash in it. Are you sayin you went thru two batteries in the last four months?

 

You indicated you finally installed a new carb. Was it a rebuild or brand new??
Dead batteries.....
Were they dead setting in the car without it running?
By dead was the starter turning over but just not firing??
Your feedback is confusing.
My first assumption is your throwing parts at a problem hoping something will stick.

 

Yes that is correct.

 

Carburetor installed I purchased brand new, mostly to eliminate any variables. As for the battery issue. I purchased a new battery for it in Sept. because the previous battery had died but was or 5 years old. The Sept battery died in December. Definition of died...I had lights, ignition, starter...car just wouldn't turn over, and eventually you'd hit the button and get a thud sound and then nothing. Put my battery tester on it and my tester failed it. It had 6v. Brought it back to auto parts store...they tested it, agreed on it being bad and gave me a replacement. At that moment i assumed shitty battery. Car started right up with replacement in December (even though i had shitty running issue once started) ...changed carb..wouldn't start...put tender on it all night. Waited till light was green yesterday morning. still wouldn't start.
Currently....i have lights, starter turns, have ignition, gauges, 6.24v at battery. My battery tester fails it. Checked for drain and there is none. I will get another battery tomorrow i cannot return this one.

It was suggested to me when the car is in the garage to remove the - cable and put the tender on the battery.

 

Battery cables, wire connections to all ignition terminals, ignition switch all need checked for resistance.
Solenoid is usually an item that will fail.
check for poor spark......It is also a good idea to have the coil rebuilt. if the distributor has not been cleaned and serviced for years. you can send the distributor and inner caps, coil, and condenser to Bubba. he can have your coil rebuilt and ensure all the components are in peak condition. Check the ignition wires for zero ohms end to end.

another good checklist.....

Using a test light or a volt meter, check for voltage at the coil primary terminal that has the wire from the ballast resistor under the dash.

If no voltage at the coil, then check the back of the ignition switch for voltage in from the battery and voltage out to the ballast resistor. If no voltage out,then clean the contacts on the switch and put dielectric grass on them.

If you have voltage at the switch both in and out then check for voltage on both sides of the ballast resistor. If you have voltage in at the ballast resistor and no voltage out, then replace the ballast resistor.

If you have voltage out of the ballast resistor and no voltage at the coil, then the wire between the two is broken.

Assume that you have voltage at the coil, then replace the condenser, which will be evidenced by a very weak spark at the spark plugs and a no start.

I have driven a flathead into the garage, shut it off and on attempt to restart, no go. Strap soldered to the condenser had come off. Stuck small screw driven in the gap to establish a connection and car started. I soldered a ground wire to the condenser and grounded the wire under a coil mounting screw.

A dirty ignition switch will produce a no start.

 

Hi Petejoe. Thank you for the info. I have replaced the ballast resistor last year as that was an issue then. I have replaced the coil very recently with a new repro. The solenoid was replaced a few weeks ago. The condenser was replaced probably last year. The - battery cable was replaced since I purchased the vehicle mainly because there was no battery when i purchased it and when i did put a battery in the cable didn't reach ( i'm guessing maybe different year cable?) Plugs were replaced last year, but the car maybe has 20 miles on it since then. i have cleaned the inside of the dist. but not replaced. I do have a second one as this car came with a pile of spare parts. Only main parts of the electrical system I have not replaced is the regulator & generator, though it looks clean and almost brand new. This car was an unfinished frame off restore, but unfortunately sat for several years as the owner passed away in 2007.
I will double check all voltages after I put battery #3 in. I will try a different brand. Battery 1 lived for 4 or 5 years and was different than batteries 2 & 3. When i did check yesterday from any drain between the - cable and the battery I found nothing. Which was unexpected. So i don't know if i just got 2 shitty batteries or something killed them. At the moment it doesn't seem like there's no drain, so maybe its getting killed when the car is running?

 

First, just to clarify some terminology. . .

Early on in the thread you mentioned that you installed a new vacuum break. When I hear vacuum break I'm thinking of the vacuum control on the carburetor that prevents flooding when cold-starting a car with an automatic choke. But am I correct thinking that what you replaced was the vacuum advance control on the distributor?

If that's the case I think there's a chance that this vehicle originally had a Load-A-matic distributor, which was a far from ideal setup even when the vehicle was new. I'm surprised that nobody, I think, has mentioned it yet. For the system to work properly requires the correct, matched combination of BOTH distributor and carburetor. The preferred upgrade though seems to be replacement with a later model or aftermarket mechanical advance distributor.

So before you pull your hair out too much, you might want to check which carb and distributor you're working with and not waste a lot of time diagnosing problems that don't respond to the changes you're trying to make. Searching "Load-A-Matic" here and on the web in general will provide you with plenty of information.

 

Even new condensers have been found to be bad right out of the box.
A charged 6 volt battery should read at least 6.3volts.
Check your voltage to the coil.