M38A1 -- Idle's OK, Stalls on Acceleration

Hi,

I have a '53 M38A1 with what seems like a very "diagnosable" issue.
The engine was rebuilt about 3 years ago and has a the correct carb.
I leave it in MA during the winter, so it sits for about 8 months at a
time before being driven again during the summer.

On to the symptoms:

The car was running fine until about two weeks ago when it began to
stall out when you step on the gas. It starts and idles well, but as
soon as I step on the gas, it revs a little bit then dies until I let
up on the gas again.

I'm not sure if the engine is flooding or starving (is there an easy
way to tell)? Any idea what would cause this?

-Steve

steve.newhouse wrote:
> Hi,
>
> I have a '53 M38A1 with what seems like a very "diagnosable" issue.
> The engine was rebuilt about 3 years ago and has a the correct carb.
> I leave it in MA during the winter, so it sits for about 8 months at a
> time before being driven again during the summer.
>
> On to the symptoms:
>
> The car was running fine until about two weeks ago when it began to
> stall out when you step on the gas. It starts and idles well, but as
> soon as I step on the gas, it revs a little bit then dies until I let
> up on the gas again.
>
> I'm not sure if the engine is flooding or starving (is there an easy
> way to tell)? Any idea what would cause this?
>
> -Steve
>

When that happens to my Jeep, I need to change the fuel filter.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

steve.newhouse wrote:
> Hi,
>
> I have a '53 M38A1 with what seems like a very "diagnosable" issue.
> The engine was rebuilt about 3 years ago and has a the correct carb.
> I leave it in MA during the winter, so it sits for about 8 months at a
> time before being driven again during the summer.
>
> On to the symptoms:
>
> The car was running fine until about two weeks ago when it began to
> stall out when you step on the gas. It starts and idles well, but as
> soon as I step on the gas, it revs a little bit then dies until I let
> up on the gas again.
>
> I'm not sure if the engine is flooding or starving (is there an easy
> way to tell)? Any idea what would cause this?
>
> -Steve
>


Like Mike said, it could be a fuel filter, especially considering how
much the vehicle sits. You might also want to check and make sure that
the accelerator pump is functioning properly. When you open the
throttle, you should see a good stream of fuel coming out of the
accelerator pump nozzle.

Chris

Hi Steve,
A weak coil and/or spark plugs will act the same way, and will not fire
under more compression, as happens went you open the throttle. Which often
happens with the change over to twelve volts, the resistor is forgoten.
Choke the carburetor with your hand will tell instantly if it a
carburetor problem.
God Bless America, Bill O|||||||O
http://www.billhughes.com/


"steve.newhouse" > wrote in message
ups.com...
> Hi,
>
> I have a '53 M38A1 with what seems like a very "diagnosable" issue.
> The engine was rebuilt about 3 years ago and has a the correct carb.
> I leave it in MA during the winter, so it sits for about 8 months at a
> time before being driven again during the summer.
>
> On to the symptoms:
>
> The car was running fine until about two weeks ago when it began to
> stall out when you step on the gas. It starts and idles well, but as
> soon as I step on the gas, it revs a little bit then dies until I let
> up on the gas again.
>
> I'm not sure if the engine is flooding or starving (is there an easy
> way to tell)? Any idea what would cause this?
>
> -Steve
>



--
Posted via a free Usenet account from http://www.teranews.com

in case you don't know, the accelerator pump is a little lever on the
carburetor, usually on the top, with a linkage arm attached to it. The arm
usually has multiple hole in it for adjustment purposes. I would change the
filter, if that doesnt cure it, adjust the linkage so that it has a longer
stroke, providing more fuel per stroke. If that works, you probably need a
carb rebuild or can get by for awhile with that adjustment. There are rubber
seals probably wearing out, causing less fuel to be delivered per stroke if
that is the fix. What you are experiencing with your carb is a common
problem, and is a off idle stumble.....very well known to mechanics.

c wrote:
>> Hi,
>>
>[quoted text clipped - 14 lines]
>>
>> -Steve
>
>Like Mike said, it could be a fuel filter, especially considering how
>much the vehicle sits. You might also want to check and make sure that
>the accelerator pump is functioning properly. When you open the
>throttle, you should see a good stream of fuel coming out of the
>accelerator pump nozzle.
>
>Chris

--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200708/1

On Mon, 13 Aug 2007 12:32:46 -0000, "steve.newhouse"
> wrote:

>Hi,
>
>I have a '53 M38A1 with what seems like a very "diagnosable" issue.
>The engine was rebuilt about 3 years ago and has a the correct carb.
>I leave it in MA during the winter, so it sits for about 8 months at a
>time before being driven again during the summer.
>
>On to the symptoms:
>
>The car was running fine until about two weeks ago when it began to
>stall out when you step on the gas. It starts and idles well, but as
>soon as I step on the gas, it revs a little bit then dies until I let
>up on the gas again.
>
>I'm not sure if the engine is flooding or starving (is there an easy
>way to tell)? Any idea what would cause this?
>
>-Steve

I agree with Chris & Muddog that it sounds like an accelerator pump
problem. Sitting that long without running could cause the rubber
seals to dry up. Changing the fuel filter would also be a wise idea
because old gasoline will develope into a "laquer". If you let it sit
very long, I would reccomend using "Stabil" (gas stabilizer) to help
prevent tha laquer build up

Good luck,
Darrell

d wrote:
> On Mon, 13 Aug 2007 12:32:46 -0000, "steve.newhouse"
> > wrote:
>
>> Hi,
>>
>> I have a '53 M38A1 with what seems like a very "diagnosable" issue.
>> The engine was rebuilt about 3 years ago and has a the correct carb.
>> I leave it in MA during the winter, so it sits for about 8 months at a
>> time before being driven again during the summer.
>>
>> On to the symptoms:
>>
>> The car was running fine until about two weeks ago when it began to
>> stall out when you step on the gas. It starts and idles well, but as
>> soon as I step on the gas, it revs a little bit then dies until I let
>> up on the gas again.
>>
>> I'm not sure if the engine is flooding or starving (is there an easy
>> way to tell)? Any idea what would cause this?
>>
>> -Steve
>
> I agree with Chris & Muddog that it sounds like an accelerator pump
> problem. Sitting that long without running could cause the rubber
> seals to dry up. Changing the fuel filter would also be a wise idea
> because old gasoline will develope into a "laquer". If you let it sit
> very long, I would reccomend using "Stabil" (gas stabilizer) to help
> prevent tha laquer build up
>
> Good luck,
> Darrell


Well, I always figured the 'accelerator' pump was so named because it
gives an 'extra' shot of gas for 'acceleration'....

It isn't needed for running.....

If it is bad, the engine will stumble or bog on 'acceleration', it won't
up and die until you let off the gas....

Just on the ones 'I' have seen anyway....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Hey your carb may also be clogged. You may want to spray some carb
cleaner in it. To see what happens. My brother has a 61 falcon and it
would do about the same thing as you are saying sprayed some carn
cleaner in it seem to run after ( now it has about 5 fuel leaks by the
engine and one on top of one of the HOT exhaust manifold so can not be
driven).



you all have fun off roading

Even a plugged up air filter will kill top end.

Mike

Jamie Mello wrote:
> Hey your carb may also be clogged. You may want to spray some carb
> cleaner in it. To see what happens. My brother has a 61 falcon and it
> would do about the same thing as you are saying sprayed some carn
> cleaner in it seem to run after ( now it has about 5 fuel leaks by the
> engine and one on top of one of the HOT exhaust manifold so can not be
> driven).
>
>
>
> you all have fun off roading
>

To test to see if that is the problem the air filter just remove the
air filter and see if that fixes the stalling. If it does just replace
the air filter. But be sure to put air filter back in after. As I am
sure you know the air filter keeps a lot of junk out of the engine.






99 wrangler TJ 2.5 lift 31 inch Good year MTR tires and a ton of
lights
Warn M8000 winch and more toys to come.