Problem that has me stumped

trainguy

trainguy

Well-known member
I have been fighting a up hill starting problem with my 46. ford for some time .I just discovered something that has me baffled.It is difficult to start but after finally starting after running poorly for about 30 seconds it starts to run progressively better after maybe one min it runs perfectly.I just started it today,same thing,I walked around the back of the car I noticed that the left exhaust sounded different than the right.I put my hand in the exhaust and the left was cold.Then I heard the engine start to run better,the left exhaust changed tone,then the engine began running properly and the exhaust was the same temp as the right.I am looking to the Barn for suggestions as to what's going on!!!!! Thanks Phil

PROBLEM SOLVED<DEFECTIVE NEW PLUGS>
 
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My ideas:

It wouldn't seem to be fuel since that is the same for both sides of the engine.
That leaves ignition as the most likely. Unfortunately you don't have very long to try to diagnose that in the 30 seconds it runs poorly. I'd clamp a timing light sensor around the high tension wire coming out of the coil before starting and see if it's missing spark during cranking or running rough. If so, you can then clamp on each spark plug wire in the left side that seems to be the problem and see which one is not working at the start. If you find one, that could be the spark plug or the distributor cap. The mystery is why it's so short lived and recovers so quickly to work fine after that. It's a puzzler for sure.
 
You have duals and left the heat riser intact on the drivers side manifold? Mayby it is sticking or it is working as it should but right side does not have this and that is why it is warmer first.
 
Prof.I tend to agree with you about it being ignition,but what would make it shut down one bank of cylinders?This is the part that baffels me.If it was fuel why would choose one bank. I know that I am close to solving the problem.I am sort of leaning to a dist. cap but I had the present one out and looked *** over and found nothing.The ign wires are fairly new.The rotor seems to be OK.The dist was reciently set up on a machine.I replaced the dist and the problem remains.Had at least 3 carbs[presently has a new English 97 on it]As I mentioned after approx 60 seconds of running it runs GREAT.
 
37 Coupe said:
You have duals and left the heat riser intact on the drivers side manifold? Mayby it is sticking or it is working as it should but right side does not have this and that is why it is warmer first.
Click to expand...

I don't think it has a heat riser but I will check.The car just developed this problem this summer.
 
trainguy said:
Prof.I tend to agree with you about it being ignition,but what would make it shut down one bank of cylinders?
Click to expand...

It most likely isn't the whole bank of cylinders. If it was I don't think the engine could even run on just 1/2 of the cylinders. All it would take is one cylinder not firing and you get rough running, low power, and a noticeable difference in the temperature of the exhaust.

All things considered, a little longer cranking and recovering fully in less than a minute is not too bad. I've been happy with less than that before.:rolleyes:
 
I have a 4 cyl propane forklift that started like that. After fixing everything that didn't need fixed, it turned out to be the head gasket. After being shut down, a slight amount of coolant deposits on the plugs electrodes and dries. When starting cold, it has to burn through that deposit before it will fire all 4 cylinders. Sometimes it will only fire one cylinder for a while until the rest gradually cut in. The colder the weather is, the harder it starts, Once warm, it starts great. If you even start it long enough to clean the plugs and then shut it off, it starts fine the next time. It didn't use any coolant, at least not enough to measure. I put some gasket and block sealer in it and it starts fine now. Too much work to change the gasket, so I'm leaving it alone.

BTW, it has a pertronix ignition on it, Mitsubishi 4 cyl, early 80's.

Try pulling and cleaning all 8 plugs next time before you start it, I bet it starts up like it should. Or maybe just clean the left bank.
 
I don't think that the problem quite matches up with the heat riser valve that forces most exhaust through the passage...but be aware that 2 kinds were used, one an obvious one with a visible counterweight bolted in between left manifold and crossover and a completely hidden one INSIDE the top of crossover. This one was a sort of warped piece of thermostatic metal called a "duckbill" which simply warped from closed to open when heated. If you have a closed valve there and the intake crossover is blocked, it might well totally kill that bank until enough heat drifts up the pipe to warm the thing.
In my experience, most '46-8 Fords have neither, with the original tossed out decades ago.
 
I had an engine with intermittent miss at cold starts. This was a 40,000 mile original (never rebuilt) 8BA.
The problem was carbon/wax/sludge coating engine/valve train/internals.


Sticky valves may be more prominent when engine is cold as carbon on the valve stem may
impose a certain amount of drag until the running engine/valve train receives lubrication.

I battled sticky valves for some time trying the oil and or water down the carb while running, oil
in the gas tank methods without success.

The solution was to pull intake, wash/scrape/brush the intake valley and valve stems with
copious amounts of low sulfur diesel fuel. Once the engine was buttoned back up I drained
crankcase and refilled (overfilled) the crankcase with 2 gallons of low sulfur diesel fuel.
Ran and drove the vehicle for about ten minutes while varying engine rpm. With over filled
crankcase, was careful not to rev/shift higher than about 2000 rpm otherwise oil may be pushed
out the road draft tube and/or the oil filler as the oil pump is capable of filling the intake valley
faster than the oil can drain back down into the crankcase.

Drained crankcase and the first engine flush showed extremely black/contaminated diesel with
much grains of carbon left in the bottom of my oil change drain pan.

Much of the discoloration/contamination was attributed to residual wax which is/was a
byproduct of certain brands of engine oil (Pennzoil/Castrol etc).

Repeated the diesel flush 4 or 5 times with subsequent short drives until drained oil became
relatively clear.


Was rewarded with a smoother/quieter engine (no more tic tic tic) as well as improved oil pressure.
The improved oil pressure may have come from changing to straight weight 40 (as Henry
recommends on all Flatheads).
Rotella T1 Straight weight 40 meets Gas engine specs for pre 1979 but is used mainly in
Diesel/Farm applications today and can be hard to find.
I purchase it at my local Farm implement dealer.




...All just my humble opinion and if running diesel in your crankcase scares you then don't do it.




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Yoyodyne said:
I have a 4 cyl propane forklift that started like that. After fixing everything that didn't need fixed, it turned out to be the head gasket. After being shut down, a slight amount of coolant deposits on the plugs electrodes and dries. When starting cold, it has to burn through that deposit before it will fire all 4 cylinders. Sometimes it will only fire one cylinder for a while until the rest gradually cut in. The colder the weather is, the harder it starts, Once warm, it starts great. If you even start it long enough to clean the plugs and then shut it off, it starts fine the next time. It didn't use any coolant, at least not enough to measure. I put some gasket and block sealer in it and it starts fine now. Too much work to change the gasket, so I'm leaving it alone.

BTW, it has a pertronix ignition on it, Mitsubishi 4 cyl, early 80's.

Try pulling and cleaning all 8 plugs next time before you start it, I bet it starts up like it should. Or maybe just clean the left bank.
Click to expand...

BINGO,,,,this sounds like the answer to my problem.will clean plugs on left bank and cross my fingers.I believe I saw moisture coming out of the left tailpipe,it maks sense,thanks. Phil
 
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My guess your dist. needs some maintance shaft bushing are worn and floating around, messing up your points setting, emmitor. elec ign.
 
Just a thought here - I had a 302 (I know, not a flathead), but was doing the same thing. After throwing lots of parts at the problem turned out it was a vacuum leak in the carb mounting spacer. Apparently as it warmed up it would and run fine. New gaskets with good spray on gasket sealer fixed the problem.
 
OK lets see what happens tomorrow morning,went down to the garage removed the plugs[no moisture] put in a set of used plugs[AL 216,gapped .028]The engione started instantly[incouraging].but the proof is will it start in the morning.Phil
 
George/Maine said:
My guess your dist. needs some maintance shaft bushing are worn and floating around, messing up your points setting, emmitor. elec ign.
Click to expand...

Good point George,
That along with the metal wire loom on the left side warrant a look. If the plugs are not the cause.
 
George/Maine said:
My guess your dist. needs some maintance shaft bushing are worn and floating around, messing up your points setting, emmitor. elec ign.
Click to expand...

The dist has been gone thru by a friend who is anal and set it up on a KRW timing fixture and checked with a Allen dist. machine.I would be surprised if the problem is in the dist.but anything is possible.The wire looms are a definite possibility.I feel that I am getting very close to solving the problem.Thanks to all for the suggestions.Phil
 
Old Henry said:
It most likely isn't the whole bank of cylinders. If it was I don't think the engine could even run on just 1/2 of the cylinders. All it would take is one cylinder not firing and you get rough running, low power, and a noticeable difference in the temperature of the exhaust.

All things considered, a little longer cranking and recovering fully in less than a minute is not too bad. I've been happy with less than that before.:rolleyes:
Click to expand...

Old Henry,

A few years ago I was driving my '34 BB(85 hp V8) and was going up a hill and around a corner it started running on 4 cylinders. My father and I chased all kinds of things including changing carbs and distributors to no avail. A compression test seemed to indicate things internally were alright for a moderately worn engine. We finally decided to take off the intake manifold and see what was going on in there. Come to find out a valve guide broke and we were losing vacuum to one bank of the carburetor. So to make a short story long the flathead will run on only 4 cylinders. It may sound funny but it will. The truck would still go 45 on those 4 cylinders too.

Red
 
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