Posted: Sat Jun 21, 2008 7:43 pm Post subject: M38 - oil in crosstube? power loss?
1952 M38. 24v, solid state regulator. A multi stage situation for you to ponder... Please excuse my rambling.
I took the M38 out today for a longer than usual drive (approx 80 miles). About 2/3 of the way into the trip I noticed some intermittent power loss/sputtering while moving (nothing much out of the ordinary at idle, but you could tell that something was up). I checked my electrical connections on the go and found nothing out of the ordinary and got her back home. I thought I'd check the points and when removing the air cleaner and flexible hose to the cross tube I noticed oil in the cross tube. Not a large amount, but enough to clean with a paper towel. With the distributor cap off I noticed a little oil in the distributor and on the points, I cleaned things up and took her out for another 2-3 miles and things were much better but there was still an intermittent power loss but not nearly like it was before. I did not remove the coil to see what might have been under there as I ran out of time and needed to get it parked in the garage again.
I suspect a combination of dirty/slightly scorched points, but am mystified as to the oil getting into the cross tube and presumably into the dist through the vent lines. My fording valves are wired in the open/non-fording position. The air cleaner is not overfilled and the element is certainly oily, but I don't believe overly so. My dipstick does not have the circular "baffle" on the stick itself.
Is it possible that oil is either being sucked from the air cleaner or pushed up through the oil fill tube and into the cross tube allowing some to get into the distributor through the vent lines causing my problem? OR could a little oil get sucked into the carb cause these symptoms, or both?
AND on the topic of oil...I use a mechanical oil pressure gauge that registers about 8-10 at a warm idle. I never really paid attention to the pressure while accelerating until today when I noticed that it seemed like I was getting 30psi at best while going 45 mph. I know it should be higher and I don't recall it being so low while driving before. _________________ Tony Morreale
Franklin, TN
Tony,
A too high oil level in the air cleaner can cause the deposits you are seeing as can the wrong viscosity oil in the air cleaner.
A malfunctioning PVC system can also introduce oil where it shouldn't be.
Over-pressurizing of the crankcase by blow-by or fording valves in wrong position can also cause your symptoms. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Posted: Sat Jul 05, 2008 8:31 am Post subject: Check your dipstick
I had this happen to me. The diaphram in my fuel pump was bad, and I was pushing gasoline right into the crankcase. Eventually when it got full enough it pushed up into the oil filler and got sucked into the carb. Check your oil for gasoline smell. When this happened to me it also plugged my carb vent line, making the Jeep run crummy, until we figured it out.
No gas in the oil. Did an oil change after the ride/incident above and all was well. I'm in the process of checking the points, cleaning the distributor, checking the plugs for fouling & proper gap.
I cleaned the PCV valve (it wasn't too dirty) and blew air through the lines to make sure they're clear, took off the fording valves, cleaned and re-wired them in the open position.
I've got a lot of distractions this weekend, but hope to complete everything and fire her up again tonight to see if the power loss has improved and if the oil returns to the cross tube.
I'm also wondering if it might be bad gas contributing to the power loss too. I had just filled up at the Shell down the road the day before the 80 miles ride and hadn't had any problems before filling up. I put a bottle of Heet into the tank before the ride... I remember having gotten some bad gas after Katrina at this same Shell station I filled up at this time around. _________________ Tony Morreale
Franklin, TN
Posted: Sun Jul 06, 2008 10:27 am Post subject: now I'm getting frustrated...
The plot thickens... I check the distributor point gap and reset to .020 (I had messed it up earlier), take out the coil and clean out the dist to make sure oil hasn't accumulated in the housing. I remove and clean all four spark pugs double checking the gap to make sure it's .030.
I put everything back together and start her right up. She runs for about 20 seconds and dies.
I try to restart - no luck. I check the carb bowl and there's fuel in the bowl and the float moves freely. I check the fuel pump to carb line and it pumps fuel to the bowl. Thinking I've flooded the engine, I let it sit for almost 24 hours and try again. M38 still won't start.
What could I have done in checking the gaps, etc that would allow the jeep to start immediately, run for 20 seconds and not start again? I know it's got to be something simple and I'm just missing it. _________________ Tony Morreale
Franklin, TN
You could have done several things. I would start under the distributor cap. Could be you didn't get the rotor all the way on and it damaged the inner cap. Could be you left a wire loose on the points. Could be you pinched a wire when re-installing the cap. Could be you didn't get the points tightened down enough. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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