Since you are short about 2 to 3 Lbs of pressure your choices are not many. The pump is bad, the can lobe is worn, or the pump is sucking air someplace. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Fri Apr 20, 2018 4:45 pm Post subject:
So do you think the surging and inability to idle would be contributed to the low fuel pressure? I was thinking about setting up my "redneck gas tank" on the cowl to see if it runs better (normally) using gravity feed. I still have to pull the engine to change the clutch, so I guess I could change the cam while it's out (I have a spare engine). I just want to make perfectly sure that the cam is the problem before I reinstall it. _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Fri Apr 20, 2018 7:35 pm Post subject:
Thanks for the specs Wes - I'll plan on doing that tomorrow. I set up my gravity feed tank this evening - still ran the same. I would've thought it would run fine like that if it was fuel starvation - my other one did for months.
I pulled the coil out (shiny case - can't say it was chrome though) and put a spare in (original military one) - ran the same. Pulled the distributor cap off my other Jeep and installed it - ran the same. Might switch the wires out tomorrow. I don't know why, but I'm thinking ignition problem. But the pump is obviously not doing it's job either - whether it be caused from the pump or cam. _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
A sticking valve will yield the roughness issue you have. As will a blown head gasket. An air pressure leak down check is the test you should do next. And do it with the engine hot! _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Sat Apr 21, 2018 7:34 am Post subject:
wesk wrote:
A sticking valve will yield the roughness issue you have. As will a blown head gasket. An air pressure leak down check is the test you should do next. And do it with the engine hot!
You're talking about a radiator leak down test? _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Sat Apr 21, 2018 5:16 pm Post subject:
Gotcha - I guess I can rent that from the parts store.
New problem. I couldn't even get it to run today - barely even fired.
I checked all of my coils using testing specs that I saw on G503 (Wes's reply to someone). The specs were 4-6ohm on primary windings and up to 14,900ohm on secondary. No continuity from any post to the case. All of my coils were slightly over 6ohm (6.2, 6.4 and 7.4) and all of them were in spec on the secondary and continuity.
I installed the new wires from my other Jeep. It still wouldn't fire - popped a few times.
I removed the entire distributor from my running Jeep and installed it - same result. Yes, I timed it to 5btdc on #1.
Doesn't make sense - should run, even if poorly. Tried spraying starting fluid - still nothing, like it's not firing. _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Sun Apr 22, 2018 11:35 am Post subject:
Thanks for the help Wes. I have decided to postpone finishing the USMC jeep until after the show next weekend. I am getting burnt out on it (SO close to being finished) with so many fails.
I came out to the shop this morning and the dread of working on it led me to just replacing the parts that I removed from my Army a1 for testing on the USMC one. I got it running without much trouble (other than not getting a spark to start with - I had the #1 & 2 wires crossed). Then she would only run on ether - I pulled fuel to the carb with my hand pump and she fired and ran without even adjusting the timing - about 5 btdc. After i get this one cleaned up and ready to go, I will continue troubleshooting on the USMC one - maybe I'll figure it out in time, but I just ran out of time this go round. (Sh)it happens!
I saw I my bank statement where WeeBee had charged my card, so I'm guessing my new top and strap set shipped. Donna said she would do all she could to get it to me for the show. Oh well, I rushed them for nothing! Thanks anyway David (if you're on here)! _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Mon Apr 23, 2018 7:15 pm Post subject:
I ran to Walmart this morning to pick up a battery for my Army M38a1 and decided to stop by NAPA to pick up points and condenser for the USMC one while in town. Once home, I installed the battery and tried to fire it up without doing anything to it (I was thinking that it might have been flooded yesterday). It still wouldn't even pop. I left that one and went to the USMC one.
I pulled the point plate and switched out the points and condenser. The points WERE pitted. I re installed the point plate, timing light adapter and dwell meter adapter. I set the points to .019". I sprayed a couple of shots of ether and she fired right up with no adjustment to the timing! I adjusted the idle down and the carb a little bit. It was raining a little, so I decided to take a ride up the driveway. It ran great until I turned around, then started doing the same thing it was before. I limped back into the shop where she idled fine!
I hooked up t he timing light and checked - around 25 BTDC if I had to guess - surprised she even ran! I loosened the distributor and adjusted to about 5 BTDC, hooked up the dwell meter and adjusted the idle to 700rpm - the dwell was fine at 42. I adjusted the carb again. She was running (idling) better than ever! It was raining a little too hard for me to take another test drive, so I started doing a little cleaning instead. I also painted and installed a replacement speedometer and fuel gauge. This fuel gauge shows full instead of the other one showing empty - at least it LOOKS like it works!
At least she is running enough to get her on and off the trailer at the show this weekend - put her on the field for people to look at, but not for driving around.
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Wed Apr 25, 2018 12:22 pm Post subject:
Today I was checking the timing and noticed that when the engine would miss the timing light would not flash. I took that as meaning that the misses are being caused by ignition (is this a "duh" moment, or can an engine missing be caused by fuel or valves?
Anyhow, I thought I would try putting the "new" spark plug cables from the other jeep onto this one - it will also look more presentable at the show even if it doesn't fix the miss. While I have the cables off, I might as well change the cap too, huh? I pulled the cap off and noticed red dust inside. Looked at the distributor and there was dust on the rotor and on point plate. The only thing red in there was the condenser wire. I checked it out and saw that the rotor had been rubbing the wire. So I moved the wire out of the way before reinstalling the cap and wires.
I fired it up and noted that it missed a lot less. I went for a cruise up the driveway - ran well. I drove around the field a couple of times and it started cutting out and wanting to die. I kept driving this time - a few more laps up and down the drive and around the field. I got her into 3rd a few times. When I stopped, I noted that she didn't act like she wanted to die and realised that she hadn't been cutting out as much! I became a little more brave at this point and hit the Hwy (for 1/4 mile) to go down a private paved road. I hit 45mph a few times up and down this road before heading home - she was running great!
My wife did say (a while back) that "maybe it just needs to be driven"! I won't admit it to her, but maybe it did!
I let her cool bank down while I did a few other things and then went for another ride - still cutting out some, but not cutting OFF - I'll consider it a win - FINALLY!
Oh yeah, UPS delivered my top and strap set from WeeBee Webbing yesterday. I threw everything on and now she's compete - but not DONE. I still have to change the clutch, get her running right and knock out a few other things like rattles and stuff not working and the wiring harness. I'll post a pic in a few.
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Thu Apr 26, 2018 6:25 am Post subject:
I'll look for a "REAL" one at the show this weekend. I have a Harbor Freight one that works OK, but I don't have a spark tester which would be nice. Thanks for the reference pics.
We definitely need to keep these old plugs alive as long as possible - anywhere from $8-15 ea and that will only get worse over time. I was lucky enough to acquire 3 sets when they first started disappearing, but with 2 Jeeps, they won't last forever.
I guess the next big electrical part that I'll be on the lookout for this weekend is coils. I sure do wish one of the US coil manufacturers would pity our hobby enough to modify one of their coils for us! I thought about emailing a few of them to see if I get a bite. _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
Personally I would continue to scout the stock coils but off shore and used would not entice me to buy. Instead I would embrace Jam's setup.
Get a dead coil, gut it and then located a modern US made individual plug coil and fit it to the stock coil innards. If you are still 24 volts add the needed resistor and voila, modern technology inside a stock looking coil.
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