My Willys 3A and 3B Community
3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: scoutpilot on March 31, 2013, 08:27:57 PM
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I'm sure some of you have been following this on the 2A and NCFFC sites. But since it is a 3A motor I put in it is with a heavy heart and the humility that only a 65 year-old motor can bring to a man that I ask for your cumulative help. Hillbilly can verify what I have done to date. After the basic install I timed the motor using the GEICO method. After getting my new springs straight (Sharp eye there, BW.) I adjusted the valves on this 3A motor to 16, per the Rule of Nine. Two exhaust and one intake are used replacements as the ones in those positions had been worn by .008. I didn't lap them. I'm running 12V gear with a 12V generator, new unadjusted regulator and old starter solenoid. All connections are solid. Battery and motor are grounded to the frame. To date, I have been through two distributers, three coils, two resistors, three sets of points, countless condensers, a new set of Autolite 306 plugs, new wires and after Ohming them out, the old copper core are back on, a new cap (checked, no streaks inside), and three rotors. I've had four different carburetors and three filters on with no change in performance. I've adjusted and tested, adjusted and tested, and here is the result. When warm it will idle smoothly with an occasional hiccup. I drop it in first gear and off we go, grab second and Its OK up to about 30mph then the hiccups start, lower end of fourth and its ok but give it a little more gas and it bucks, snorts, stumbles, cuts out and in and I can't get above 40 mph. I'm near desperate at this point. I dread going in a third time. Help? Please?
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At this point it's probably best to forget everything you've already done and begin again. It is frustrating but we have all been there. From a distance it sounds like a fuel problem. Try driving with a fuel pressure gauge attached to see if the pressure drops off under load.
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I suspect a vacuum leak. They can do weird stuff to an engine. Spray around your intake with a can of starting fluid or the like and see if it picks up. I had a similar issue with my 225 V6. I rebuilt. Turned out to be a bad intake gasket. I didn't have a loss of power since it was only one cylinder. I would think this would have a bigger impact on the 134.
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]My list is long and I forgot a few things. AC572 single action fuel pump rebuilt 4 months ago puts out steady 4.5 PSI. I have used up two cans of Starting fluid in vain search for vacuum leak from top of carb to intake manifold flanges. Manifold vacuum 20-22HHg with only very slight rock.
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How is the compression of the engine? I had a 2A with horrible compression and that thing wouldn't get out of its own way.
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How about a fuel pressure regulator? I changed from a Solex to a carter and left the regulator set at 1.5 lbs. It runs fine. Just a guess.
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Here is a real shot in the dark, how is your cam? The previous 225 I had threw an exhaust lobe and that caused it to spit back through the carb at high RPMs and did other weird things. It idled fine because it was opening just a hair, but not enough at high RPMs. Something like this on the 134 would do some very strange things because you only have 60 horses to begin with and when it is working hard, you definitely have a loss of power as you describe.
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Here is another shot...could the fuel outlet/feed at the tank be partially blocked?
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Scout...
The only time I had similar symptoms, it ended up being a fuel delivery issue. It only acted that way when I was hard on the throttle, in 3rd, on a soft incline. I was demanding more fuel than the system could deliver. Fuel blockage. Replaced my fuel filter and the hiccup went away.
That's the best I can offer. You've done everything else...X4.
Tim
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How is the compression of the engine? I had a 2A with horrible compression and that thing wouldn't get out of its own way.
Nate, warm compression is (1) 70, (2) 72, (3) 80, (4) 72 and you are the second person to mention the cam. The bucking is, while not violent, abrupt and short duration shuddering.
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That compression sounds low, but that is what my '49 has about, 80 across the board.
On the fuel issue, my '49 had the needle seat in the carb keep on plugging up so very little fuel could get in. It did about the same thing as you describe too. Try replacing the fuel pump too with a brand new one. You said it was rebuilt several years ago. The one on my '49 started to go bad, and that caused problems. I replaced it, and they went away. The old one pumped, but not enough. This ethanol destroys the rubber. I've heard of the rebuild kits not being as great as a new pump for some reason. It could be that when the fuel pump sat dry, the ethanol screwed it up.
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With 50 being the absolute minimum for operation, I'll take 70psi for compression. I guess you missed the part about four different carbs and two fuel filters with no improvement to same problem across the board. The fuel pump has been active since rebuild. I had it on the motor I pulled out of Blue and transferred it to this one. It gave me no problems before. This motor ran like a Singer Sewing Machine when I pulled it.
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As Bob W said, hard to diagnose from a distance. You seem to have ruled out primary and secondary ignition systems with the components you have replaced. Fuel pressure seems OK, but need to double check volume as others have said. Have you installed a vacuum gauge? Look for the obvious, low vacuum or fluctuation under load. Could be a sticking valve, weak valve spring, worn cam as previously mentioned restricted exhaust system. You have the basics of fuel, compression and spark but they need to be at the correct time. You seem sure that the timing is correct but do you have worn gears or chain? Just a few suggestions that come to mind.
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I have a vacuum gauge in line to test carbs. Idle is 20-22 in/hhg. With an occasional tiny blip accompanied by a burble in the exhaust and a bounce of the heat riser lollipop. Heat riser is working fine. My points don't have a helper spring. I'm looking into that. And the fuel line from the tank.
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You could try using a temporary electric fuel pump with a pressure regulator fed from a clean gas can. Run it directly to your carb and see if it makes a difference.
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With 50 being the absolute minimum for operation, I'll take 70psi for compression. I guess you missed the part about four different carbs and two fuel filters with no improvement to same problem across the board. The fuel pump has been active since rebuild. I had it on the motor I pulled out of Blue and transferred it to this one. It gave me no problems before. This motor ran like a Singer Sewing Machine when I pulled it.
I know you replaced carbs and fuel filters. I am trying to relate to issues I've had. Not enough fuel on two occasions has caused similar problems for me. You have already eliminated one by swapping out carbs. I would still try changing out the fuel pump. Like I said, when it went dry during the engine swap, that could have damaged it.
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I don't see how it could dry out in two weeks.
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What is the vacuum reading under load/driving? A restricted exhaust will cause vacuum to drop under load and result in lack of power. Valve timing issues due to worn gears or chain or sticking valves/weak springs will will cause fluctuation under load. When you say "hiccups" are you referring to actual backfires through the carb or exhaust or minor misfires?
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I don't see how it could dry out in two weeks.
It is a possibility. You said you are at a dead end and I'm throwing out ideas. It is worth a shot.
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I'm going back in to gradually, to carefully check the valves. OH well, at this point I think I've got one sticking or not seating correctly. I am keenly aware of the difficulties trying to diagnose a problem over the net. I humbly thank you all for your efforts to help. I will let you know the outcome.
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Scout,
After I rebuilt my engine I had a similiar issue caused by several things. �Hesitation under load and occasionally popping through the carb. �I did the same checks with the points and condensers, fuel pressure, rebuilt the carb, checked the valves... �To make a long story short, double check your timing. �When I was completing my rebuild I incorrectly timed my engine and all I needed to make my engine run great was advance the timing about 10�. �
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Just pulled the valve cover and fired it up. Half the tappets are not turning.
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At this point you need to confirm that the engine is internally OK. You have changed everything external.
I had an XPAG chew up a cam due to the zinc being removed from the newly formulated motor oils. �It took a few years to figure it out. Do a Google search to check out solid tappets and zinc.
Best of Luck
Steve
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I give up. Monday I am going to seek the advice of an older gentleman just down the road from me. He works on older flat head tractors a lot. I am at wits and expertises's end. If he can't help me with an easy fix. Blue may not appear at the show. I have begun the process of putting a new piston and all new rings in the red head motor that I removed from Blue. I will more than likely fix the leaking rear main seal while I am at it. Yeah a motor re-swap. No parts from Walck's yet. Cross your fingers.