no power

J

John MacDonald

Member
I have a stock 239 in my 1948 2dr, to make a long story short, my car sat for couple months, went to start, would not idle unless choke on,not sure what the problem was, played guessing game, replaced fuel pump and then carb, will idle now and sounds like power house when not moving, but will not produce enough power to pull herself up small incline in my driveway. Any thoughts.:mad:
l
 
Can you roll the car by hand in the garage? If not check brakes per GB Sisson advice.



When trying to go up the incline, does the engine rpm go up, but no pull? That would be a badly slipping clutch.



Need more symptoms.
 
Rule out clutch issue .... Outdoors, with hand brake firmly on and wheels blocked, does the engine stall when the clutch is engaged in first gear ? Rule out the seized brake issue .... does car roll on level floor ? Rule out Ignition issue: Starts and idles decently. Check timing. Does engine accelerate uniformly in neutral ? When idling, hold your hand near exhaust pipe discharge - does pulsating discharge feel like all cylinders are firing ? When rev'ing engine do exhaust gases feely exit ? Rule out Fuel issues (with air cleaner off): You're getting gas. Is that replacement carb a recent rebuild ? Gas should squirt into both carb throats when you activate the accelerator pump on the side of the carb. Check your throttle linkage for smooth and proper operation. Disconnect gas line at carb. Using container to catch gas, use starter button activate that new pump and check for continuous flow from tank. Check carb gasket, manifold and distributor connection for vacuum leaks. Check fuel bowl gasket for possible air leaks. Are manifold passages clear ? (people have been known to drop rags in them) Starts and idles with the choke partially closed BUT do you have to keep choke closed to any degree to rev engine ? Check and adjust carb settings with a vacuum gauge.
 
Last edited:
Sticky valves perhaps? (Sticking open) Pretty common problem with these old flatheads if they're let sit for a while.

Start her up. Let it run for a while.
Try squirting a bit of oil in each plug hole.
Start it up again. Put a brick on the accelerator (a light one !) and go for a coffee while it's running.
Try this a few times over a couple of days. Wouldn't hurt to spray a LITTLE bit of oil down the carby while she's ticking over.
The valve stems get a coppery looking glaze over them which makes them stick. Worst case scenario is you might have to pull the heads off, whip the valves and guides out and clean the stems up with fine sandpaper, and the guides, and lube them. Make sure they slip up & down in the guides easily. You know the score. Oil them up a bit when you reassemble them.



Good luck



Cheers


Mick
 
old trick run a small amount of two stroke oil in your fuel about 250 mils to the tank wont smoke but its enough to stop things sticking as modern fuel are very dry by comparison to fuels from the 40s
 
Checked all things that were suggested, car rolls freely, no sticking clutch, put oil down spark plug holes twice, will try road test tomorrow. Funny thing is I did compression check first thing all cylinders running 100-125.All most certain must be some valves not seating all the way.
 
John MacDonald said:
Checked all things that were suggested, car rolls freely, no sticking clutch, put oil down spark plug holes twice, will try road test tomorrow. Funny thing is I did compression check first thing all cylinders running 100-125.All most certain must be some valves not seating all the way.
Click to expand...

valves are not the problem with very good compression like your engine has.
 
Throttle linkage binding or otherwise not getting full throw? Are the nozzles for the accelerator pump squirting?
 
John MacDonald said:
Checked all things that were suggested, car rolls freely, no sticking clutch, put oil down spark plug holes twice, will try road test tomorrow. Funny thing is I did compression check first thing all cylinders running 100-125.All most certain must be some valves not seating all the way.
Click to expand...

Critter nests in the exhaust? Pickup in fuel tank blocked :confused:
Try taking the muffler out of the loop.

Bob
 
John, swap a known good coil and see what happens. My 48 coupe would idle fantastic but under load fall flat on it's face and barely keep running. I thought fuel and tested, accordingly replaced. Ended up changing the coil and the problem was solved.
 
Check the ignition resistor. Strap it out and see what happens. I had one that quit when it got hot. Worked good while cold. Changed it out and what a difference.
 
You must log in or register to reply here.
Back
Top