M38A1 Running Terrible!!!

[MASH 4077]

I was out driving my Jeep a few nights ago & it was running fine. The next thing I know is its missing out & has no power what so ever. So I pull the spark plugs thinking I've fouled a couple of plugs(which it already has a problem doing) So I pull all four plugs & they are fine. Running a little rich but good enough to run. So I clean up the plugs, re-gap & put them back in. Same result. No power and is missing out like crazy. So with me being a guy that has only ever messed with electronic ignition I'm not the greatest with points. Could this be my problem? Also tonight while trying to get it running my dad cross threaded one of my plug wires. Could this also be a problem with a miss? The cap & rotor also don't look the greatest. Could this be where my problem is? Just a tune up issue?

 

[emmado22]

Tine for you to become aquainted with points/condensor! Replace cap and rotor too! That should fix it.

 

[MASH 4077]

So you think its the points & condenser? It runs but it runs well.... words I cannot say on here.... Where is a good place to pick up my replacement parts?

 

[zout]

Call John up at Midwest Military - catch him on the web site for your parts - great service.

You can get a chaser to clean up the plug thread - but it sounds like you may need some experience behind you to take on this task.

Check your fuel pick up tube in the tank and make sure it is not full of pinholes and sucking air on you as well - check fuel supply & pressure.

Plugs-Points - check resistance on the coil and make sure it is not breaking down on you as well (THIS IS what the TM's are for).

 

[MASH 4077]

Thanks! On the plug he cross threaded the plug wire to the plug. Not in the block (thank goodness!) I also have the TM's on a cd rom. I just need to print them off so I don't need to use a pc every time I have a problem.

 

[clinto]

On any gas engine, driveability issues are chased in the following order:

1. Ignition system up to specs. If it hasn't been "tuned" recently, then that means plugs, wires, points, condensor, rotor and cap. Only you (or an oscilloscope) can determine if you need to replace the expensive wires. Just keep in mind, you'll feel mighty dumb rebuilding a carb and endlessly retuning it only to find you had a bad wire intermittently dropping. Lots of people set the gap on points, the right way to do it is to measure the dwell. This eliminates inaccuracies in point gap due to worn distributor shaft blocks, etc.

2. Once the ignition system is kosher, if it still runs bad, the fuel system is all that's left. You can check the pressure output of the fuel pump with a gauge and see if it matches the specs in the TM, make sure fuel filters are fresh and clean, tank isn't gummed up, etc. If all that is good to go, then it's the carb. If you have the correct YS950 carb, then Midwest Military has the high quality kits with the good gaskets to rebuild it.

NOTE: All this assumes an engine with good compression, correct timing, etc. If you are unsure of this, run a compression test.

 

[JGBallew]

I was out driving my Jeep a few nights ago & it was running fine. The next thing I know is its missing out & has no power what so ever. So I pull the spark plugs thinking I've fouled a couple of plugs(which it already has a problem doing) So I pull all four plugs & they are fine. Running a little rich but good enough to run. So I clean up the plugs, re-gap & put them back in. Same result. No power and is missing out like crazy. So with me being a guy that has only ever messed with electronic ignition I'm not the greatest with points. Could this be my problem? Also tonight while trying to get it running my dad cross threaded one of my plug wires. Could this also be a problem with a miss? The cap & rotor also don't look the greatest. Could this be where my problem is? Just a tune up issue?

Okay, you had a major change in performance while running? That's (as others mentioned) is almost always ignition related. Carb issues are usually of the "creeping crud" variety (though with some of the crap gas today, not a hard and fast rule!).

Pull the cap, and check the rotor , and the little carbon button in the cap. Check the little spring that contacts the coil (They like to fall out or people forget them and stuff in whatever.)
Then check the points and condenser. Just look for loose wires or signs of burning/shorting. Gently tug on every connection, and check for security.

Look in the cap, and check the screws that hold the plastic part in the housing. Look for cracks or soot.

Also, seconding Midwest. Pretty much my Go-To for M38A1 stuff.

 

[MASH 4077]

Well I did check the distributor contacts. They had a little crud on them. Those are now cleaned. The points I'm going to say are trashed. Had a HUGE groove in the contacts and the felt had some oily stuff on it. So thats where I'm starting. I did order my points, condenser, & rotor from Midwest. I think this will get me by for now. I'm going to save some $$$ so I can buy and Inner & outer cap and wires. Just takes some time. They were very nice & helpful! I will be making another purchase from them!

 

[Beacher425]

If you are wanting to get rid of points and condenser and switch to electronic ignition and stay 24v, try here: M151 / M38 Solid State Ignition Kit, 5704857

Here are the instructions: http://www.surfacezero.com/g503/data/500/ignition.jpg


Took about 15 minutes and runs great. No perminant changes so I can switch back anytime.