Got it going straight....

[idiocrates]

....now I'd like for it to be "going" straight better. My newly acquired 1955 M-38A1 has been significantly civilized or sumptin. Some of the things that have been done to it include:
1. apparently all the fording passages have been removed and or plugged
2. the carberator either changed or modified
3. the fuel pump does not have a vacuum pump and I think a fuel pressure limiter added to the fuel line between the pump and the carb
4. the carb does not have a 90 degree air hood. There is a large dia. rubber hose bent over with a sharp bend that rubs on the underside of the hood between the air cleaner and the carb air hood
5. The throttle control is gone

The engine seems to be running ok......it starts fairly easy and idles ok once the engine gets warmed up.....but there is a significant tendency to flood out durning warm up and a pretty bad hesitation at acceleration and just by smell it seems to be running pretty rich.

Do these problems sound like they could all be related to the changes made to the fuel system and could I realistically expect better performance if I was to invest in a new (and more correct) carb? It is not my intention to enter this jeep in the Indy 500......but it is used to climb the rocky hills in west Texas and slow and steady and smooth is a definite must so please.....any opinions are greatly appreciated. Thanks.

Jim

[wesk]

First post some photos of what you have. Then we can help ID whats there and suggest improvements.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[idiocrates]

Here's a link to some photos of the jeep I am working on:

http://www.flickr.com/photos/22032113@N02/sets/72157603507766764/

Any comments would be greatly appreciated.

Jim

[tdavis]

How does it run if you take that crazy radiator hose turned into a breather hose off of the carb? Looks like a kink in that hose at the carb could be severely restricting air flow.

It is amazing the mods you see on some jeeps.

[idiocrates]

I haven't taken the hose off yet but the engine runs remarkably well. I suspect from the smell of the exhaust it is however running sort of rich....so go figure. Kinda hard to imagine that the airflow isn't at least somewhat restricted. I don;t know if you can see it or not......but the hose actually rubs on the bottom of the hood and its rubbed a hole in the hose. The previous owner solved that problem by wrapping the air pipe with black electrical tape. At this point I'm thinking I will probably try to find one of the Carter YS carbs with the right angle air horns to put back on this engine.....its just a matter of finding one at a price I can live with.

Jim

[wesk]

That's an old one barrel GM Rochester carb. The fuel pump is a dual Gas/Vac but it's a later CJ unit but will work just fine.

A CJ3B or CJ5 YF938 series carb will be a lot cheaper, easier to find and will work just fine.

Throw the hose away and buy the Willys 90 degree tin adapter for the civeey carbs. Dirt cheap and will solve air in while letting you keep the original M38A1 air cleaner you have.



The flow pressure regulator is to reduce pump pressure to something the Rochester can handle.

Go to Midwest Military and buy a new filter assembly for your M38A1 in tank filter also.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[idiocrates]

Okay.......if I go with the YF938 carb......will I still need the flow/pressure regulator.....or can I remove the thing?

Then you said "buy a new filter assembly for your M38A1 in tank filter also." This jeep is no longer equiped with the under-the-driver-seat fuel tank.......its been replaced by one mounted in the frame in the back under the cargo bed. So, is the YF carb like highly susceptible to a stuck float valve from junk in the gas and is it just good SOP to change the filter periodically.......or is this just to eliminate the filter mounted next to the fuel pump?

[wesk]

Since we aren't standing next to your jeep we can only assume something is there until you tell us it's not. I reviewed your photos and did not see a rear mounted tank. Perhaps it's time for you to come clean with us and list ALL the non stock items you have then our advice can be more accurate.

The YF938 series is an excellant carb and has been substituted for hundreds of YS950S military carbs over the years. It is designed to be used with the fuel pump you have in the photo. The small inline filter next to that pump is a common practice when the original M38A1 tanks started to rust and cause problems.

Not knowing what fuel tank you have in the back I cannot offer any advice on filters for it. The inline will most likely have to do. And yes that little inline filter needs to be changed periodically.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[idiocrates]

Yikes......I'm not real sure I can list ALL the altered things on my jeep since this is the first one I've ever been close enough to to look under its hood......but I'll try:

1. converted to 12 vdc with an alternator with internal mounted regulator
2. carb replaced
3. fuel tank replaced with one mounted under the bed in the back......and honestly......I haven't even gotten back there to poke around yet. All I know for sure is there is nothing leaking fuel anywhere at this time.
4. both seats replaced
5. I have a one piece windshield
6. vacuum hoses and motors are gone from the windshield wipers.....I have no wipers at all
7. all of the gauges are replacements. The speedometer may be original but the lens is too cloudy to see through.
8. a rollbar with bracing has been added behind the seats
9. rear bumber replaced
10. cross bar tires replaced with Firestone atv civi tires

......and beyond this there are probably a ton of other less noticable things that have been altered but which I am not sharp enough to know about. I will try to add some additional pictures to my album showing some more general views.

[Cacti_Ken]

Jim if it weren't for all the cactus in you area I would bring my M38 out there and ride around the hills with you haha. I used my jeep on hunting leases out there before the restore on it. As worn out as the motor was it could take those rocky ledges just fine in low range. I did have fun.

Ken
_________________
Tropical Veteran
35th Inf. Reg. "CACTI" 4th I.D. VN
Amateur Radio K5XOM

[idiocrates]

I hear you.......and our cactus is probably about as bad as it can get. If anybody ever figures out an economical way to fend off cactus thorns they will probably make a mint off of me alone between truck tires, trailer tires, tractor tires, and atv tires. The dump is full of tires that have lots of tread on them but are soooo full of cactus thorns they are more trouble then they are worth trying to keep 'em inflated. I've only had this jeep for a few months and so far its working out vey well on the rock ledges. Creep is the name of the game and 4 low handles the bumps and the drops very well. And what the heck.....the cows seem to like the sound of the old engine.......so go figure.