Flathead 239 still hard to start after much work...

[rjlester]

I thought I would start a new thread on this problem as I put my first thread in the wrong forum, you can see that thread here: https://www.fordbarn.com/forum/showthread.php?t=324907

Car is a Canadian 54 Meteor with a Ford 239 flathead (original engine was a 255, Canada got the flathead one more year).

So, the problem is (still is) that it is hard to start, but once running runs not too bad at all. The engine history is completely unknown, but it is absolutely spotless outside, and I suspect it was possibly rebuilt, and maybe they never got it running right, like the problem I'm having now.

Compression has improved greatly from 50/60psi across the board to now the worst has 85psi, and four or five are at 105psi. This is since I've been running it in the garage, and short drives around the neighborhood. My seemingly perfect running flathead in my other car are all 95 to 100psi.

Here is a list of what I've done:

- Rebuilt carb (not with a kit) using my ultrasonic cleaner. Blew out all passages. This was badly needed as it was corroded inside.
- Changed spark plugs with known used but perfect working plugs.
- Verified points are at 15 thou.
- Spark seems healthy.
- Cap and rotor look like new inside.
- Changed the coil as the one it had I measured to 8k ohms. The used one I put in was about 4.5k.
- Is the coil wired backwards? It had the + on the distributor wire side so I switched them. No change.
- New spark plug wires.
- Drained the fuel tank, and put in fresh fuel tonight. That helped a bit.
- Changed intake gasket, it was leaking and one bolt was missing from the manifold. When I cup my hand over the carb, the suction is REALLY strong now. Cupping my hand over it still smooths out the idle. Strange.
- I've tried to adjust the mixture screws, when you turn them in, you can find the spot when it starts to sputter, but when turning them out there is no point that it sputters until they almost come out of the threads.
- New starter solenoid and battery. Cleaned connections and it turns over and sounds just like my other 6v flathead that starts and runs perfect.
- Checked timing with a light, seems to be advanced about an inch before the mark on the pulley. Tried retarding it, same problem with starting and it sure runs rough when I retard the timing.
- Removed the two pennies that were blocking the heat risers under the intake.
- installed new 180 thermostats.

In order to start it, you have to pump the gas about 1/3 of the way many times, and then it will start. It is not flooding, I've tried flooring it to no avail. I've tried choking it fully with the manual choke, that doesn't work either most of the time. It has been like this since I started working on it. The changes I made have made slight improvements, but I'm used to my other flathead which will fire if you just bump the key!

If you get it started, it immediately runs perfect and idles smooth. Shut it off, try to start it right away and you have to pump the gas many times in order to start it again.

I'm wondering if this is a rebuilt engine, and maybe the camshaft lobes have gone flat from the lack of starting it before I got it. I wish I looked closer when I removed the intake, I didn't even think of that possible problem until now.

I'm going to do another compression test tomorrow, the battery was low and I was only getting 70psi on 1,2, and 3 cylinders. I hope that is just because the battery is low and not a loss of compression. Battery is on the charger overnight.

When I drive it, boy does it lack power too. Really sluggish. Sorry for the long post, hope I haven't missed anything, been working on it for a couple weeks now.

[GB SISSON]

Vacuum leak? Try plugging the outlet to the wipers and spray carb cleaner or unlit propane torch around leak prone areas. That, combined with the low compression from sitting. At idle, drizzle some marvel mystery oil down the carb. While you are at it, add marvel to the fuel and oil. I have had two engines recently brought out from many years storage, where the compression went from poor to good with this treatment. After a few hundred miles of hard driving compression went to excellent. One more thought is something I tried on my H flathead six with very sticky intake valves. (stored 30 years). At idle, fog some WD 40 down the carb until it almost dies. repeat, repeat. If you have a vacuum gauge, have it hooked up while doing all this. I have found that seeing the results of your efforts on a gauge instead of 'thinking' there was some improvement is a far better way to go while troubleshooting. Keep us posted. Good luck and post up a pic or two of this merc. Edit: Do the compression test on a warmed up engine with throttle fully open.

[rockfla]

The fact that your Idle mixture screws are not effecting the idle as you back them back out is concerning.......BITE the bullet, box your carburetor up and send it to CharlieNY (Charlie Schwindler). This way you will KNOW with 100% certainty that is is working 100% properly and can eliminate that from the "cause" list of possibilities. After about 4 turns from bottom the idle screws "SHOULD" start effecting the idle again from bottom!!!!


Charlie Schwindler
5845 Cole Road
Orchard Park NY 14127
(716) 440-8952

[RalphG]

My 52 Merc flathead has always been a bit fussy about starting if you don't use the right techniques. If it has sat for a week it will need priming the carburetor or else grind away on the starter til the battery runs down. Manual choke conversion and it needs full choke on a cold start. Even on a hot start I find it helps to give a pump or two on the gas pedal for an easy start. Mine is the Holley "teapot" but I'm assuming yours being a 239 does not have the same carb.

[pistonbroke]

Something about the timing mark bothers me. My brothers 255 had sheared the woodruff key on the crank but that is rare. I'm wondering about the cam timing since it won't run with the timing set closer to normal. Just me thinkin what would I do in your place, I would pull the timing cover and check my marks then my firing order on the plug wires. After that the carb would be my next go to. You talk about compression and although it's important it's not a deal breaker. My old 41 pickup has a couple at 40 psi ,80 psi and 4 at 100 psi. I drove it everywhere until the transmission went south. It started and ran good although a little on the gutless side. there is my two cents, Tim

[rjlester]

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Originally Posted by pistonbroke

Something about the timing mark bothers me. My brothers 255 had sheared the woodruff key on the crank but that is rare. I'm wondering about the cam timing since it won't run with the timing set closer to normal. Just me thinkin what would I do in your place, I would pull the timing cover and check my marks then my firing order on the plug wires. After that the carb would be my next go to. You talk about compression and although it's important it's not a deal breaker. My old 41 pickup has a couple at 40 psi ,80 psi and 4 at 100 psi. I drove it everywhere until the transmission went south. It started and ran good although a little on the gutless side. there is my two cents, Tim

Funny you mention cam timing, I was talking to a friend last night, and I was wondering what the repercussions would be if the cam was off one tooth? I will start with the firing order on the plug wires, maybe they are clocked wrong.

[rjlester]

Originally Posted by GB SISSON

Vacuum leak? Try plugging the outlet to the wipers and spray carb cleaner or unlit propane torch around leak prone areas. That, combined with the low compression from sitting. At idle, drizzle some marvel mystery oil down the carb. While you are at it, add marvel to the fuel and oil. I have had two engines recently brought out from many years storage, where the compression went from poor to good with this treatment. After a few hundred miles of hard driving compression went to excellent. One more thought is something I tried on my H flathead six with very sticky intake valves. (stored 30 years). At idle, fog some WD 40 down the carb until it almost dies. repeat, repeat. If you have a vacuum gauge, have it hooked up while doing all this. I have found that seeing the results of your efforts on a gauge instead of 'thinking' there was some improvement is a far better way to go while troubleshooting. Keep us posted. Good luck and post up a pic or two of this merc. Edit: Do the compression test on a warmed up engine with throttle fully open.

I have the wiper and power brake ports plugged, so no leak there. I will put some more marvel mystery oil in the tank and oil, I did put some in the tank before, but I've flushed the old fuel out. Also, I think I'll change the oil just for the heck of it, it has turned very dark and is probably diluted with gas. I like the idea of WD going down the carb. Might do that every evening and fog it heavily, then let it sit overnight.

[kurt v]

Did you change the power valve ?

[rjlester]

Originally Posted by kurt v

Did you change the power valve ?

I didn't change it, I do have another one in a used carb, I could try that. What kind of symptoms do you get from a failed power valve? I haven't had a bad one before.

[kurt v]

Get a couple of new ones that will be soft and not dried out, make sure the base is cut flat and not tapered to make a good seat.

[rockfla]

When you rebuilt your carburetor, did your butterfly shaft have wear in it??? Did you check that as well as the above mentioned "power valve"??

[rjlester]

Originally Posted by rockfla

When you rebuilt your carburetor, did your butterfly shaft have wear in it??? Did you check that as well as the above mentioned "power valve"??

If I turn the mixture screws all the way in, the engine will stall. From what I understand, if it stays running the power valve is blown.

There is a very small bit of wear in the shaft, I've had much worse wear in other carbs that worked ok. That being said, I do have another throttle body I could try, although it has a similar amount of wear.

Sometime in the next month, I will be purchasing a complete 54 Ford parts car from a guy I know, but I won't have access to it for quite a while. I know the carb is on it, would be good to have a complete carb to compare to...

[rockfla]

You stated in the first post " I've tried to adjust the mixture screws, when you turn them in, you can find the spot when it starts to sputter, but when turning them out there is no point that it sputters until they almost come out of the threads."

IT should also effect how it runs after a certain point of backing them out AS WELL.....You are saying "it doesn't"!!!


You have also stated "When I cup my hand over the carb, the suction is REALLY strong now. Cupping my hand over it still smooths out the idle. Strange"

Which, to me, says, IF I limit the air entering the carburetor, the engine runs better......SO.....YOU are drawing a vacuum "somewhere" it should not be.....ALSO the first statement above says that the idle adjustment screws are NOT performing AS THEY SHOULD which ALSO tells me you are drawing a vacuum where you should not be. ALL this tells me, even though you rebuilt your carburetor, IT still is not functioning AS IT SHOULD. One would think THAT, IF you are sucking MORE AIR than FUEL, that, in my mind, tells me IT COULD be, at minimum, a contributing factor IN your hard start issue!!!! Call me crazy BUT there are four things needed for an engine to run.....Compression - which you have stated you have pretty good readings all in all, Spark - as you do have it running and Idling, Air - you are still breathing where you are typing SO you have air, Fuel - which you are getting under "most" conditions.....BUT NOT ALL!!!!

Hence, my advice to send your carburetor to CharlieNY, who is "THE MAN" when it comes to carburetors......He test runs them BEFORE he sends them back to you!!! The last one I sent, I didn't even have to adjust the idle....He hit it dead on - plug and play!!!!! It is worth the "insurance" and peace of mind IMO, to have someone like Charlie (who knows your carburetor inside and out, sideways and upside down) and his work and KNOWING its done right, running right and not having a care in the world as far as that piece of the puzzle is concerned!!!!! AND get the proper fitting POWER VALVE too!!!

[rjlester]

Update: Cold compression is 80 to 95.

I know what you are saying rockfla, but I think the vacuum leak is elsewhere. I sprayed WD40 liberally this morning on the throttle shaft, no change in idle whatsoever. Not saying the carb isn't the problem, but the shafts are not leaking like I originally though.

I dumped Marvel Mystery oil down the carb, and I could NOT make it stall! It would drink so much of it I just couldn't believe it. There must be another vacuum leak somewhere.

[mhsprecher]

"BITE the bullet, box your carburetor up and send it to CharlieNY (Charlie Schwindler)" Agree with that.

[Flathead Fever]

One of the first basic tests you do is vacuum test. When you do a compression test you should always do a vacuum test too. Stick a vacuum gauge on a manifold vacuum port, not a venturi vacuum port and tell us what the vacuum is at idle and how steady it is. If you do not have a manifold vacuum port you can get a carb spacer that does have one. Watch a video on what the different needle readings mean.

As suggested, check for vacuum leak, run a propane bottle around the intake and carb and see if it effects the idle. I have never seen a vacuum leak that made an engine hard to start, only that they idled poorly after they started but anything is possible. I was a fleet mechanic, but we also were required to have CA State Smog Test and repair licenses since we smogged our fleet vehicles inhouse. I couldn't do my own cars which sucked. I had 17 ASE licenses, and I still got my butt kicked every once in awhile diagnosing stuff. When I retired, I let all of that stuff expire because I'd rather clean toilets for a living than ever work on cars and trucks ever again. I'm having a little motivational issue getting out in the garage and working on my own stuff It's a fun hobby, its a poor choice for a career. I had this happen to me one time at work in 30-years, I had an engine that was lean at idle and I had tried everything trying figure it out. I finally clamped off the t PCV hose so there was no suction coming out of the crankcase and put some propane into the oil fill cap on the valve cover, the idle immediately came up. That told me I had a vacuum leak on the inside of the engine. Pulled the intake and there was about a 2-inch piece of gasket missing next to one of the intake ports. On a flathead you could remove the oil breather cap and stick a piece of paper over it, blowby should push the paper away but an internal vacuum leak will suck the paper down. I doubt this is your problem but it's something you can try.

When you rebuild a carb not only do you blow all the passages out with air, but you also take a can of carb cleaner spray, with the straw tip and force the straw against each passage and verify a spray is coming out the other end of the passage. It works better than the compressed air because you can see how much the passage is flowing, plus it cleans any varnish out of there. Pull your mixture screws out (don't mix them up) open the butterfly up so you can see below it, stick that carb spray straw down in there and see that if it has a good spray coming out of the idle ports.

It is unusual that backing the A/F screws out all of the way makes no difference. You turn the screws in it does lean out the mixture so that kind of rules out another fuel source like a power valve leaking. It might have partially plugged idle jets. Still, it runs and idles after it starts so it should be getting enough fuel to start from the accelerator pump (verify it squirts). The idle passages might be slightly plugged but not the cause of the hard starting. Then you said its runs poor going down the road so that would be when it's running off of the idle jets and on the main jets. You could have a couple problems going on. A vacuum leak would affect it at idle but not as much driving down the road, you might not even notice it all off of idle.

I would put the timing back to where it is supposed to be. Verify the dwell and timing are correct. Set the dwell first and then the timing. Dwell changes timing, timing does not change the dwell. Then always do your air fuel mixture adjustment last. Setting the Point gap using a feeler gauge is okay but you should be checking it with a dwell meter too. Verify the advance system is working. If you don't have one buy an "adjustable" timing light. It allows you to measure the amount of advance you are getting since you don't have timing marks other than the initial timing mark. The adjustable light has a wheel that when you rotate it moves the advanced timing light mark back to zero. Then you read the degrees you turn the wheel, and this tell you have much advance you have. It has nothing to with your hard starting problem, but you need one of these to verify your advance system is working properly, incase it's the reason for the sluggish driving.

When you can't find a problem externally then you pull the timing cover and verify the gears were lined up properly. When that doesn't ix it you pull a head and verify the valves are opening at the correct time by decreeing the camshaft. If it was an already good running engine you would know the parts were originally made correctly. With new parts it's always a possibility they were made wrong, its rare but it does happen. Start with that vacuum reading and tell us what it reads.

[Flathead Fever]

You said you switched the wires on the coil. It sounds like it was already correct. Since its a "positive ground" system the positive terminal on the coil would go to the distributer. It would be the negative terminal going to the distributer on a negative ground system. The coils are wired differently inside for negative and positive ground systems. You need to make sure you have the correct polarity coil. It will run hooked up either way and probably would have nothing to do with the hard starting but it will have an effect on the ignition system. Here is a very good article explaining why coil polarity is important.

https://mgaguru.com/mgtech/ignition/ig104.htm

When you do your compression test again make sure you hold the throttle blade open. Air needs to be able to get in there and fill-up the cylinder to get an accurate reading.

[3twinridges]

Hey flathead fever, that’s interesting on the adjustable timing light. Can you explain that again? I have set a distributor on a Sun machine, by adjusting the springs, but unsure how to test that on the engine with an rpm meter and the timing light you mention. I just have a standard light to set initial timing with the distributor disconnected.

JB

[Flathead Fever]

Originally Posted by 3twinridges

Hey flathead fever, that’s interesting on the adjustable timing light. Can you explain that again? I have set a distributor on a Sun machine, by adjusting the springs, but unsure how to test that on the engine with an rpm meter and the timing light you mention. I just have a standard light to set initial timing with the distributor disconnected.

JB

I had a hard time finding a picture of one with the adjustment knob. I guess that's old school. They are almost all digital now. Mine is a Sun adjustable timing light with the knob on the back. Here are some photos of a Craftsman one. Since our fleet was a licensed smog test and repair station the State had a list of mandatory tools we had to have. One tool was an adjustable timing light for checking total advance.

Say your timing is 4 degrees at idle on your flathead which you verify with your timing light. When the knob is set to zero the timing light works like any other timing light. You just need to remember to always set the knob back to zero hen checking the initial timing, or you will get the wrong reading. Then you raise the rpm and you will see the liming mark move away from the pointer as the timing light shows it advancing on the pulley. When you see it at its most advanced spot you rotate that knob until it brings the timing mark back in line with the pointer (were still at that elevated rpm). Rotating the knob offsets when the light flashes in degrees. By reading how many degrees you rotated the knob to bring that 4-degree mark back in-line with the pointer, plus the 4 degrees initial timing, you will know your total advance. I don't know how accurate it is compared to a distributor machine, but I bet its close.

We used it to independently check the degrees of mechanical advance the centrifugal weights made by raising the rpm, with the vacuum advance disconnected. Then at idle, when the weights were not working, we applied a handheld vacuum pump to the vacuum advance and checked its amount of advance. Then you raise the rpm with a vacuum gauge on the hose to the advance unit and make sure the vacuum advance is getting the correct vacuum signal. Many of those units are adjustable using an allen wrench through the vacuum hose hole so you can dial it in exactly to the factory specs. Same with changing the springs on the weights. You can make the advance come on sooner or later using weaker or stronger springs. Using a tachometer and that adjustable timing light you can tell how much advance at what rpm you are getting. I wish I could have found a video showing one in use and then it would made more sense.

[Brendan]

Originally Posted by rjlester

Funny you mention cam timing, I was talking to a friend last night, and I was wondering what the repercussions would be if the cam was off one tooth? I will start with the firing order on the plug wires, maybe they are clocked wrong.

i had put i new cam in a Chebby motor with a double roller timing chain, the cam gear has 3 timing marks , i had put it together wrong. it took me about a hour and a half to get it to run, it had no power from a start. also it would spit fuel out of the air horn of the carb, when you would accelerate. then i suspected valve timing. one saterday i puled the engine and advanced the timing. that took care of the trouble