She's just not starting

Hello,

I suppose I should de-lurk first: I'm Michael, live in NH and MA, I'm 22 and bought an M725 as a project last December. I'm a novice so you'll have to bear with me.

It ran and started fine at first, and started right up in Feb when I pulled it out of a month of storage. Since that time, I've fired it up about once a week and it has been harder to start every single time. Now it just doesn't start at all. The engine cranks and cranks and just doesn't want to catch. Spraying starter fluid into the carb doesn't make much of a difference. Fuel filter is full of gas and fuel pump is squirting out fuel. Spark plug arcs when removed, and spark plugs were relatively clean when I pulled them. Didn't really see any gas on them after trying to turn the engine over, though. Managed to bump start right away (that was an adventure!) and I rode all over town without a problem, except for some backfiring when accelerating in 2nd. That never happened before. Idled fine though, but didn't want to start up again after I let the engine cool.

Everything stock. 24V. Fuel filter, carb and starter have all been rebuilt. Distributor is fairly new. Spark plugs and cables are new.

Any thoughts? Anyone from NH or MA?

Unrelated: what shocks do y'all recommend?

Thanks for hearing me out.

i still havent put my shocks on. i cant tell to much difference.

if you have air,spark and fuel it has to run.

you need to tell us what engine/ignition you have. ill try and help

Spark plugs!

Idling and lots of cold starts are bad on plugs. Especially if the engine never gets warmed up. A lot of bad plugs will show a spark with no pressure applied against them. That is why plug testers use air pressure and a little chamber to simulate actual combustion conditions. Used plugs that work great at 0 pressure will often do nothing above 80 psi. On vehicles that I know I'm just going to start, move ten feet, kill and then do it again in a few weeks, I pull out the good plugs and just stick in something that will make it start. Then When I am done painting or whatever to the vehicle, I put back in the good plugs and drive the hell out of it.

I have always understood the shocks to be kind of a un needed fashion statement for these trucks. The job of a shock is to control the rebound of the springs. As pointed out by our math and grammar major, Bumpr, when our springs flex more than an inch, the vehicle has exceeded its max payload. That means that the springs aren't flexing much at all in an unloaded truck. So, if you want a smoother ride, I would suggest you lower your tires air pressure and save your shock money for something else. Like new spark plugs.

I'm guessing that "Everything Stock."means it's a 230 Tornado.
When you say "Bump Start" do you mean Jump Start? Like from another electrical source? or did you roll start it? My first guess would be weak batteries,where you are getting fire,but weak. Have you ever done a compression check on the engine. You can have air,spark and fuel,and with low compression not get combustion. I would check the timing(dynamic)if you can bump start(?) it again.-Just some thoughts.

hmmm. i missed that. i fought coil and condensors, till i gave up in mine

I did a lot of long runs: by "weekly starting" I didn't mean fire it up and let it die. Bump starting meant roll-starting it, not jumping. Roll-starting it worked fine. It's the original 230 OHC Tornado with stock carb, pump, distributor etc. The spark plugs are fairly new.

It cranks fine. Is it possible the batteries (old!) are strong enough to crank the engine fast but can't provide sufficient spark?

I was asking about shocks since the body kinda bounces up and down as I drive.

Did you GAP the plugs properly? I'm just asking,no offense :)

How fresh is the fuel? Today's fuel goes bad a lot more quickly than it used to. In fact it leaves a residue like clay mud in the fuel lines and carb if it sits too long.

Check your batteries....Sounds like to me that they have enough to crank, but not enough for good spark...but when you roll it your not cranking the engine by starter so you have good spark to the plugs...Also check your ground...make sure you have a good ground as that will play hell with your system if you don't. Put a battery tester on each battery by them selvs and check them (disconnect them from each other and the system.) Also check your terminals....Lastly how does the volt gage look? Is it in the green? You may be wearing down the batteries and not charging them back up....When trouble shooting alsways start at the simplest and work your way to the hardest.

look down the throat of the carb and see if when you open the throttle lever there is a stream of gas shooting out. if not that could be your problem, the excellerator pump isnt workin thus not giving you an initial squirt of fuel to start it with. probably not your problem since youve already tryed starting fluid but alot of possibilities exist. you might also check fire for strength and see if it will jump a gap of about an 1/8" at the plug end while cranking it over. if not it could be from low battery voltage ( discharged or bad battery) weak coil, not enough voltage at coil while cranking, short in dist ( not too likely), cap or rotor or wire problem. check fire on more than one wire. look for carbon tracking lines inside cap and burnt spots too. Good luck and hope you get er fixed.

the m37 i drove at work to plow snow. would do the no start thing it was the points and condenser. the very same m37 is for sale at auction-gsa in fort collins.

rick

The issue was timing. As a buddy was cranking the engine, I wiggled the distributor until it caught. Now it starts on a dime. The timing isn't exact since it's still chugs a bit during acceleration. I can't fine-tune it since my timing gun can't get a reading through the shielded spark plug cables. Does anybody know how to use a timing gun on these vehicles? Is there an adapter?

Is it normal for timing to go drastically off within a year or so's time? How would I know if I have a worn timing chain? Can I replace the timing chain through the valve cover or do I have to take the whole engine apart?

Thanks for the advice everyone. Happy Jeeping.

There are two hold downs for the dist. Check both verify they are tight. One is into the block, the other is in the bottom of the dist housing, facing up from on the exterior.

The entire timing cover must come of the front of the block to change the T-chain. Just rig a short a newer plugwire and plug to check your timing, then reinstall your OE when you have it set right.

Doug

If you want to check the timing for cheap, you need:
a 7MM solid core wire and ends...try a small engine repair shop, lawn mowers and such...
Autolite #275 plug, the civvy equivalent
Put the ends on the wire and remove the stock wire and plug from #1 cylinder. Carefully push the timing wire you made through the lid and into the cap until you are sure it is fully seated.iiit is possible to break the tower on th cap where the wire goes down through it so be careful or you'll be buying another cap...just go easy...then put in the new plug and hook the wire to it. You can pull another vehicle, 12 volt, up near the truck or use a 12 battery that has charge, to power the timing light. Clip the lead on the new wire and time away.
It is very common to buy an M715 and find the timing 40 or more degrees off....
brute4c

The army made a kit that had a short about 6 inches adaptor wire that would screw into the spark plug and then srew into the water proof wire. You then had a section of non shielded wire to hook the light to. I also just hook up to one of the 2 batteries for the light. The kit also had an adaptor for the distribitor to get the rpms and dewel. If your going to keep the vehicle stock it is worth the money (40-100 bucks depending on condition) for the adaptor kit.

What about using a vacuum gauge to set timing? Where can one purchase this army tuning kit?

You can also use a vacuum guage to get the timing really close. Hook the guage up to manifold vacuum, start the engine and twist the distributor until you get a maximum vacuum reading, then retard the timing until the guage reads 1" less than the maximum reading you obtained. That should get you very close to the proper timing. Good Luck.

Just look around on the web for M series vehicle tune up kit or ignition kit. Many dealers had them...There was a flood of them on the market a few years ago when the Army went to its all diesel program.