HELP

This is the place to get help with technical matters concerning your M151 jeep

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CaptB
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HELP

Unread post by CaptB » July 21st, 2018, 12:44 am

H guys, I am new to the world of mutts. Bought myself a 1975 A2 ex Greek Army and for the first few weeks it ran like a dream. It then started cutting out on me after about a mile, let it sit for 5 minutes and it started up again no problem, but would then cut out after a short distance. I have changed the fuel pump, the coil and the condenser. It started yesterday on the first crank, ran for 20 minutes with the hand throttle out, idled for 10 minutes never missed a beat. Took it down the road and about the exact same place it cut out on me again. Any ideas as it's driving me mad

Mark
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Re: HELP

Unread post by Mark » July 21st, 2018, 1:53 am

fuel filter, something in gas tank, fuel pump, float in carburetor??? I've had similar problem caused by the previous.The trick was catching at the moment of failure. Also I had points cause the same behavior
mark


1968 m274A5
1960 m151
1981 m151A2
1964 m416
1971 m416

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m3a1
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Re: HELP

Unread post by m3a1 » July 21st, 2018, 2:16 am

Welcome. You came to the right place. Be of good cheer. You have a runner and that's half the battle, right there.

First, attempt to isolate the problem. Let's start with fuel delivery since you swapped in a fuel pump. I'm assuming there was a reason for that. My suggestion is that you get a can of starting fluid and keep it in the truck. As soon as it conks out, pull the elbow off the carb, give it a generous shot, slip the elbow back on and see if it will start again. Doesn't matter if won't KEEP running because a shot of starting fluid is just a shot and it's gonna run out....but, if it starts after adding the ether, you have very likely identified a fuel delivery problem.

You haven't said anything about having a fuel filter. I run a Fram G12 which is just a clear plastic fuel filter and may cost you all of $3 at Walmart. Having such an item in-line between the fuel pump and the carb allows you to see what's being dredged up from that old fuel tank. It also allows you to see how much fuel is getting up there. Buy two, put one on the truck and keep the other in your OH S**T Kit.

Do the simple tests first, before throwing a ton of new parts at it because every time to change something, you've changed the paradigm of the problem.

BTW, if you happen to have the Chinese 24v coil (usually shiny chrome) most of us here on the g838 consider those to be suspect straight out of the box they came in and they can produce the same problems you are experiencing. Not saying they are totally junk but you get what you pay for and they fail regularly.

I recently had a gremlin very similar to yours. It turned out to be the pickup tube filter in the fuel tank (which had received the full BUBBA treatment many years past and was finally in its death spiral). I cannot overstate how important and how often neglected that filter is.....and SO easy to acquire and replace! So consider replacing that, if only as a general maintenance item.

Whatever you do, apply the KISS principle. Keep It Simple, Sir!

There's a lot of knowledge on this site so by this time tomorrow you're going to have quite a few responses, and to help us help you, you really should take a few pics and post them here. Not only do we like pictures, allowing us to have a good look at your truck (especially under the hood) will often turn up a few hidden problems you probably didn't even know you had.

Now, go fix that MUTT! We're here for ya!

Cheers,
TJ
Last edited by m3a1 on July 21st, 2018, 10:52 am, edited 1 time in total.

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Horst
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Re: HELP

Unread post by Horst » July 21st, 2018, 5:48 am

I had quite similar issues when I got my jeep and it was dirt in the fuel tank. Open the filler of the tank and try to reach down to the bottom of the tank. Or have someone with thin arms doing it. Check if there is rust or dirt at the bottom of the tank (and yes, doable with all the fuel still in the tank).

What you also can do within a few minutes without too much trouble is checking if there is gas in the float chamber (and if there is a lot of dirt in it). There is a drain plug at the bottom of the carburetor. If you want to check if there is gas in the carb after it stopped, before you try starting again, remove that plug and see if a good amount of fuel comes out. This will should give you a good indication if you have a fuel delivery issue. This is very easy to do and should be done before you start removing and disassembling the carburetor. Catch it with a container if you want to check for dirt in the fuel. This check can be easily done while somewhere on the side of the road but also do it first after you started the engine at home. This way you have a good indication how much fuel should come out of the chamber and you can compare later on after the engine quit.

I agree with TJ that you should install a clear fuel filter. Should look like this: public_html/wiki/doku.php?id=zenith

There is a dedicated section on fuel issues in our Wiki: public_html/wiki/doku.php?id=fuel_feed_problems

As already described, the other issue can be the ignitor not producing a spark because of either a bad ignition coil or a bad electronic module (if it is not the points type). Take a spare plug with you and as soon you get the trouble, remove one plug cable, insert the spare plug and check if you have a spark while everything is still at operating temps. Same here, a roadside check taking you only a few minutes.
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

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rickf
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Re: HELP

Unread post by rickf » July 21st, 2018, 3:20 pm

If the coil you put in is a shiny coil then it is a Chinese coil and it is not at all uncommon for them to fail within several miles. You may go through two, three or four of them before getting one that holds up. Sad part of owning a M series.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

CaptB
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Re: HELP

Unread post by CaptB » July 22nd, 2018, 1:08 am

Hi guys thanks for the feedback. First off, I did buy a shiny new coil, so probably chinese, however I did manage to fry it by leaving the ignition on (learned that lesson) anyway it was replaced by a non chinese part. I changed the fuel pump because I couldn't get fuel through to the filter, I blew back the line to the tank and it was ok, so changed out the pump and it worked. There is a plastic inline filter fitted and it shows fuel in it, although the fuel only comes up halfway, is this normal. The engine has the simple ignition system no electronics and the points have been replaced before I bought it and look ok. I plan to change both filters and I will also check out the in tank filter as suggested (are these readily available). I will take her for a test run and as advised take quick start with me and try and prove it's a fuel problem. I have attached a few photos as requested.

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m3a1
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Re: HELP

Unread post by m3a1 » July 22nd, 2018, 2:17 am

Ok, new information. So you boiled a coil. It happens. Are you feeling confident about the health of your condenser?

As for acquiring parts, check out the G838 Resource List. Many of those suppliers also sell their wares on eBay, by the way.

We are still considering that fuel delivery may be the problem....so, from your comment, you are showing fuel all the way to the filter and your replacement fuel pump is putting fuel up there. In-tank filter is still in question but if there's fuel in the filter I would have a hard time claiming that's the issue. So far, so good.

During normal operation, the clear filter doesn't necessarily need to be full, but if it's ridiculously low, obviously that ain't kosher.

Now, depending upon your particular carburetor, there may yet be one more filter to consider. I know....filter after filter after filter. Crazy, huh? But there's a reason for that. The carburetors on these trucks have more in common with the carb on your lawnmower or portable generator than they do with "modern" automotive carbs. So, it is critical that their internals be kept free from debris.

So, go to this link (this links to my project which you can find elsewhere on this site.) Scroll down and look at the first two pictures...

viewtopic.php?f=27&t=10252&start=30

I don't want you to get too wrapped up in the written details on my post (which really has nothing to do with your situation) but I DO want you to take a good look at the content of the first two photos. What I want you to notice is that one of those pieces has a screen filter built into it. I would have to assume that your carb is otherwise in generally good condition since it has been running, but since your pictures aren't coming through as yet we can't still can't see your truck. It's important because sometimes, what is invisible to you, jumps right out at some of the old hands here.

In any case, you can see my carb in the background and from the photo, it should be obvious where that piece came from and where you might find it on your truck. IF your truck will restart with starting fluid (an indication of fuel starvation) this bit might just be something you'll want to check. Simply remove your fuel line and carefully back that piece out and have a little look-see. This check won't cost you a cent and will take only a few minutes.

Now, keep in mind that we aren't really into the internals of your carb just yet. All we're doing at this point is ensuring fuel is getting there! Slow and steady wins this race.

There are a number of things carburetor-wise that may be the cause of your trouble but let's just make sure the fuel is getting all the way there first. Once that is done, we'll move on to the other possibilities, such as the possibility that your carb's internal valve, as actuated by the float, may just be getting stuck closed and sometimes, just giving the carb a good solid rap is enough to dislodge it which is really only a temporary fix.

In the mean time, getting some pics up for us will be very helpful. On this site, go to Board Index, then General Discussion and the fourth topic down will give you detailed (and easy) instructions on how to post pics here.

Cheers,
TJ

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Re: HELP

Unread post by CaptB » July 22nd, 2018, 4:03 am

Thanks TJ I will check this out. Quick up date, after starting to look at the fuel system I saw that there were bubbles in the plastic filter and these were worse when the engine was hot. My thoughts were that the pump was suckling air from somewhere, so decided to check the lines all the way from the tank. Lifted the seat and found that the tank gasket has gone and I had fuel pooling around the top of the tank (glad I gave up smoking some years back) So going to order a new gasket, fit that and work my way back to the car. I will update when this is done.

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Horst
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Re: HELP

Unread post by Horst » July 22nd, 2018, 4:36 am

my clean filter is almost full with the engine running. So you might have found something...
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

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rickf
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Re: HELP

Unread post by rickf » July 22nd, 2018, 9:18 am

Ok, We need to determine what feul system you have here. The parts that TJ is referring to are the filter in the carburetor which is only on the 12848 A1 carburetor. You say you have a 1975 which should be a 13660 A2 carburetor. You mention replacing the fuel pump and also gas pooling on top of the tank. Only two ways for it to get on top of the tank. Either a leak in the supply lone coming out of the tank with an A1 electric pump or a leak in the return line of the A2 system. I am leaning towards the second one and if so that will not cause the problems you are experiencing. The filter fluid level that is visible will never show full due to the location of the inlet and outlet tubes inside of the filter. SO, Assuming you have an A2 fuel system with the mechanical fuel pump on the side of the engine there are a couple places you can be getting air into the system. The most likely is the diaphragm on the pump is cracked or loose. Try tightening the screws around the pump body just a little but not so tight you destroy the diaphragm. other areas to look for area any places you have rubber lines between the fuel pump and the tank and the connections between the lines and the metal lines.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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m3a1
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Re: HELP

Unread post by m3a1 » July 22nd, 2018, 11:10 am

If you are in a hurry to proceed, you can go to OReilly's and pick up a sheet of cork gasket (ours had two thicknesses, so select the thicker one). That gasket is 8" in diameter. You can figure out what the inner diameter is. Cuts nicely with a pair of scissors and obviously you can figure out where the holes go just by laying it on the piece. Punch those out with a regular hand-held paper hole-punch. Should take you all of 10 minutes to do correctly. Cheaper than buying one ready made and you get to have quite a bit of extra material to keep on hand. Bonus!

Rick is referring to the A1 in-tank fuel pump. You'll recognize it immediately when you pop the top on that tank because it is about the size of a largish soup can whereas the A2 just has a shepherd's hook-shaped fuel line which is supposed to have a filter stuck on the end which is about the size of your index finger. Remember these trucks can have become a crazy mix of parts over the years. Anyway, that fuel is either being pumped up out of the tank or it's dribbling out of a loose or compromised fuel line or fitting.

Now let's take a moment and help train you to help yourself on this site and get immediate answers. Click on our G838 Wiki (top right). Then click on Crossover Parts. There, you will find that the Airtex 60577 fuel pump can be a suitable replacement for an our mechanical fuel pump. They only lack a small vent-line nipple that you can get along nicely without having. You might find you have some minor plumbing issues to do to get the lines hooked up but that's about it. The benefit of the Airtex is that it costs somewhere in the neighborhood of $16.00, unlike $200 for a NOS pump which is already decrepit from years and years of sitting around (like so many of us :lol: ) ...and did I mention that having a spare Airtex in your OH S**T Kit would be a very good idea indeed?

Please take a moment and do what you have to do to get us some pictures. There's a ton of collective experience here at the G838 and many of these guys can spot problems a mile off if you will only take the time to allow us to see what we're dealing with. I promise, it will pay big dividends!

Cheers,
TJ

CaptB
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Re: HELP

Unread post by CaptB » July 23rd, 2018, 12:50 am


acudanut

Re: HELP

Unread post by acudanut » July 23rd, 2018, 5:05 pm

Do M1's and M1A have a coil. ??? Where ?...Wait.. under the dist. Cap.
My mind was getting confused with the 66 injected jeep. (banging head)
Last edited by acudanut on July 23rd, 2018, 7:59 pm, edited 1 time in total.

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Re: HELP

Unread post by Surveyor » July 23rd, 2018, 6:01 pm

Pics from Acudanut. While there appears to be a separate coil (yellow top) mounted on the fender for the fuel injected engine, the original should be located under the distributor cap towards the passenger side where it is "waterproofed." Capacitor is located in the silver cap area on the side of the distributor as seen in the second pic... you can see where the line was cut in the first pic.

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1960 M151 Run #1
"There is one nut on a M151 that is very difficult to remove....." - K8icu
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Re: HELP

Unread post by acudanut » July 23rd, 2018, 7:54 pm

Did this freak anyone out with all that crap on the pass. side engine compartment ?
This was a 1 of 2 fuel injected jeeps made by ford. I got rid of that engine and all that wiring crap today and I only have one problem. Wire Number 568 from the 60 amp Gen. I can't seem to figure out where and how to make it ground properly.
Last edited by acudanut on July 23rd, 2018, 8:04 pm, edited 1 time in total.

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