Power loss, in high RPM. |
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NormanSalido
Member Joined: 15 Feb. 2018 Location: Kansas Status: Offline Points: 48 |
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Posted: 31 May 2018 at 5:26am |
gentlemen I need your knowledge and help, so from a couple days back my 48 2a is having issues with power while I'm driving usually in 2nd and 3rd gear the engine starts making weird noises kinda like multiple fast backfires and at the same time I'm losing speed and power, im uploading a video so you guys can see. it's hard to explain.
things I've done to the jeep lately. installed a new exhaust (stock brand new from walks) changed the inline filter before the electric fuel pump installed NEW fuel filter before the carb it's a W-O by the way changed the spark plugs 925 autolites new air filter ( paper one rigth on top of the carb) New distributor cap the spark plug cables have less than 200 miles on them. don't have a clue what else to do or what could be the problem. hope you guys can help. Thanks.
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NormanSalido
Member Joined: 15 Feb. 2018 Location: Kansas Status: Offline Points: 48 |
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ndnchf
Member Sponsor Member x 2 Joined: 22 Sep. 2017 Location: Virginia Status: Offline Points: 2177 |
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Link doesn't work for me. Why do you have two fuel filters? Is your tank full of crud? Each filter adds a small level for resistance to fuel flow. It could be fuel starvation at high speed.
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1948 CJ2A - It goes nowhere fast, but anywhere slow.
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mbullism
Member Sponsor Member x 4 Joined: 29 May 2015 Location: MA Status: Offline Points: 4785 |
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If you copy and paste the link text it'll get you there... if it came on all of a sudden id be looking at vac leaks and timing advance... but only after I swapped out the dreaded condenser, lol
Edited by mbullism - 31 May 2018 at 12:19pm |
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Those who do not learn from history are doomed to repeat it... Welcome to 1930's Germany
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48willys
Member Joined: 22 June 2007 Location: sw/ virginia Status: Offline Points: 1341 |
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Backfiring often is a timing problem, only doing it at high speed makes me think that it could be your timing advance. I would pop the cap and check the points to be sure that they are gaped right and check the advance to see if it's missing springs or is stuck.
It could be a broke valve spring that's not closing the valve quickly enough. I have had fuel problems make this problem too, but I run two filters without any problems. |
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1946 cj2a #28680
1948 chevy 3800 thriftmaster 1946-50's cj2a-3a farm jeep 1993 yj, aka the yj7 |
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athawk11
Member Joined: 18 Jan. 2012 Location: Arvada,Colorado Status: Offline Points: 4151 |
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Just throwing this out there because it's a common issue and the the part is cheap. A bad condenser can have this effect. Unfortunately, the replacement condensers are mostly junk, so even if you replace it, there is no guaranty that you'll get a good one.
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1- 1946 CJ2A
2- 1949 CJ3A |
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oldtime
Member Joined: 12 Sep. 2009 Location: Missouri Status: Online Points: 4186 |
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Going EXCLUSIVELY by the sound on your video .
It certainly sounds like it is backfiring through the carburetor and not through the exhaust.
In other words it sounds like unburned gasses are going back into the air filter system. Is this sound coming out through the air filter ? If that's the case it may seem logical that high RPM misfire may be sign of bad valves , guides or weak springs. Really need to try and narrow this down to a fuel or a firing issue.... |
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Currently building my final F-134 powered 3B .
T98-A Rock Crawler using exclusive factory parts and Approved Special Equipment from the Willys Motors era (1953-1963) Zero aftermarket parts |
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NormanSalido
Member Joined: 15 Feb. 2018 Location: Kansas Status: Offline Points: 48 |
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this sounds really interesting, I can't be 100% positive that is coming from the air filter, I only does it will in movement because if I just accelerate it while stopped it's good. ( so I'll try to take the hood off and take it for a ride, see if I can figure where it's coming from specifically.
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NormanSalido
Member Joined: 15 Feb. 2018 Location: Kansas Status: Offline Points: 48 |
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gentlemen I really appreciate all your responses, i will be doing some tests on my condenser and I will order a new one and hopefully I'm lucky enough and it works.
I'll be doing some more research in the subject and I will let you guys know what I come up with! Thanks again!!!
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ndnchf
Member Sponsor Member x 2 Joined: 22 Sep. 2017 Location: Virginia Status: Offline Points: 2177 |
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FYI, I've read here on the forum that 6v condensers should be in the .23-.25mfd range. 12v are a little higher, .25-.30(?). I got new points and condenser from Walck's a month ago, but have not yet installed them. The other day I was curious about the new condenser, so I checked it's capacitance. It came in at .30 mfd. I have some older condensers from other antique vehicle laying around. I need to dig them out and see what they read. The old Volkswagon community is big. I wonder if the German Bosch condensers would work. They might be better quality than the currently available condensers of celestial origin.
Edited by ndnchf - 31 May 2018 at 5:39pm |
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1948 CJ2A - It goes nowhere fast, but anywhere slow.
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cpt logger
Member Joined: 23 Sep. 2012 Location: Western Colorad Status: Offline Points: 3043 |
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X Whatever on the condenser. It is a cheap & easy test. Just buy 2 or 3 of them, unless you buy the German Bosch one, then just one should be fine. German Bosch condensers will work. I have used them on almost all of the old junk, errr umm I mean, fine antiques, that I work with. I buy them for a 1964 VW beetle, 6 volt, from VW. Then I use them on anything 6 to 8 volts. They work well & I believe that they are better than the stuff from your FLAPS. IHTH, Cpt Logger.
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oldtime
Member Joined: 12 Sep. 2009 Location: Missouri Status: Online Points: 4186 |
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If one has no definitive approach, then it is certainly logical to start changing parts.
But change only 1 item at a time or you learn nothing at all.
In lie of having ample spare parts It's most economical to change the the least expensive "suspected" components first. I fully agree concerning the microfarads of capacitance, if this is an ignition issue as opposed to a fuel issue. But simply installing untested condensers leaves room for doubt. An ignition related issue will tend to backfire through the exhaust system. Often times when I'm fine tuning a Willys engine I stand on the RH side. I'll run a length of straight pipe back to the tailpipe and use it like a megaphone . That way exhaust sound is clear and crisp. I helped a friend tune his high mileage F-134 the other day. It idled O.K, but misfired badly with increased throttle For starters I static timed it but he wanted to put a timing light on it and get it right on at 5* BTC So he did and with the strobe we could easily see that the timing fluctuated from retard to advance. I told him the distributor shaft was causing the timing fluctuation. Edited by oldtime - 01 June 2018 at 12:39am |
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Currently building my final F-134 powered 3B .
T98-A Rock Crawler using exclusive factory parts and Approved Special Equipment from the Willys Motors era (1953-1963) Zero aftermarket parts |
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NormanSalido
Member Joined: 15 Feb. 2018 Location: Kansas Status: Offline Points: 48 |
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so this is my approach, I've been searching widely and i want to try doing the easiest things first before I start taking the engine apart!
is there any easy way to test if its the springs, valves and guides? and the other thing I don't understand is why is it only making it while in movement? any advise on how to check the timing? will this create the misfiring too? |
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oldtime
Member Joined: 12 Sep. 2009 Location: Missouri Status: Online Points: 4186 |
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I'll suggest that the very first thing is you need to precisely adjust the valve tappets.
Both intake and exhaust to .016" tappet clearance. Do this by way of the "opposing valve technique". If you can't find really good info that has already been posted then we can advise you further. Please note to us concerning your existing tappet settings.
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Currently building my final F-134 powered 3B .
T98-A Rock Crawler using exclusive factory parts and Approved Special Equipment from the Willys Motors era (1953-1963) Zero aftermarket parts |
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Mike S
Member Joined: 20 May 2006 Location: West Coast Status: Offline Points: 2318 |
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Missing only when under load seems likely to be a timing issue?
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'47 CJ2A -- #114542
Warn FF D41 rear Lock-Right locker 11" drum brakes Dual master cylinder T90C Transmission 16 X 6 Jeep truck wheels Cooper STT Pro tires |
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Bruce W
Member Joined: 29 July 2005 Location: Northeast Colorado Status: Offline Points: 9652 |
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Or resistor plug wires on a 6V system? Or defective resistor plug wires? I can't open the video either, but if you are running one of those cute little chrome, paper-element air cleaners, you might try a test drive without it. BW
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It is NOT a Jeep Willys! It is a Willys jeep.
Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You! We Have Miles to Jeep, Before We Sleep. |
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RealDeal
Member Joined: 14 Aug. 2012 Location: Denver, CO Status: Offline Points: 101 |
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Any updates? Did you try running it without the air cleaner? I'm having a very similar problem. I'm losing power with a similar noise but only under load or when going up hills in 2nd or 3rd gear. (I drove while hitting the gas and brake in 2nd and 3rd gear to simulate a load on flat ground and was able to reproduce the problem).
But if I leave the air cleaner disconnected, the problem goes away for the most part. I'm curious what you find...it may help me figure out my problem. I verified the air cleaner is clean but I cleaned it anyway just to make sure. I'm thinking the backfiring through the air cleaner idea someone mentioned earlier might be what is happening.
Dave |
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1949 CJ2A #219707
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Ol' Unreliable
Member Joined: 25 Sep. 2016 Location: CO Springs CO Status: Offline Points: 4226 |
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Welcome back, Dave! Where ya been?
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There's a reason it's called Ol' Unreliable
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