Knocking and back firing when gas panel is down

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
dinof
G-Major General
G-Major General
Posts: 2860
Joined: Fri Jan 08, 2010 4:32 pm
Location: Arcadia & Johannesburg Ca.

Re: Knocking and back firing when gas panel is down

Post by dinof » Fri Jun 16, 2017 7:32 pm

Go 8 volt???? Why? It's a 6 volt system. :?
Dino Falabrino
On the "G" since 1998.
1943 GPW 102310 DOD 3-3-43
1928 Model A Roadster Pickup
1930 Model A Tudor
1968 Taco Minibike


Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Fri Jun 16, 2017 8:10 pm

Going on 8v why.
Because it will start easy, head lights bright. I have few ww2 vehicles on 8volt and I never had problems with them, headlights are still working for four years.
I have few spare original jeep 8v regulator. And I have a spare 8volt 60 amp alternator I bought on eBay.
We use resistors on coil so it stops it over heat. And I do have an 8v battery charger.

ilya323
G-Private First Class
G-Private First Class
Posts: 13
Joined: Wed Oct 29, 2014 1:22 am
Location: Moscow, Russia

Re: Knocking and back firing when gas panel is down

Post by ilya323 » Tue Jul 04, 2017 4:41 am

Peterdodge6volt wrote:Hi folks
So far me and my friends jeep expert mechanics do some work on her.
We fix the crack on the valves engine block, we change timing chain, we change distributor plus cables, we did some new wiring on her.
We also did find one conrod nuts loose so we replace new nuts and washer on.
Everything is back on except the head as I am still waiting on new head gasket.

We check all the valves they were all fine no cracks, damage, burn out, no broken springs and nothing is loose..


I will let you know when the head is on and how it's running. Finger cross

Me and my friends suggest that we are going to go 8 volt on her.




Cheers Peter
What's news?
Did you find choke valve plate?
My Willys MB Project (only Russian Language. Sorry. But you can leave your comments in English)
http://www.drive2.ru/r/willys/1132113/

Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Tue Jul 11, 2017 3:44 am

Hi Gens
I put everything back and new head gasket.
She run fine and took her for a drive about 30 minutes later for a drive just got home as soon as I stop everything came back again back firing, black smoke, and running funny again as before. I am so pissed off.
I took the manifold off again and the crack on the block came back which didn't help at all.
The engine already off the jeep and I bought a brand new engine and it's going into the jeep.
I clean my 2 spare jeep engine and they both have crack on the block as well.
What is happening to this engine. Why is jeep engine gets cracks on block then dodge.
I now have to look for another original jeep engine block without cracks so I can do a fully rebuild for spare.


Thanks for all your help Gens I appreciate it. Keep EM rolling



Cheers Peter

ilya323
G-Private First Class
G-Private First Class
Posts: 13
Joined: Wed Oct 29, 2014 1:22 am
Location: Moscow, Russia

Re: Knocking and back firing when gas panel is down

Post by ilya323 » Thu Jul 13, 2017 3:24 am

Where is the crack on the block?
Can you take a pic?
My Willys MB Project (only Russian Language. Sorry. But you can leave your comments in English)
http://www.drive2.ru/r/willys/1132113/

Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Mon Aug 28, 2017 11:48 pm

Hi gens
Well the engine is on progress now, I bought a brand new engine block from Ian copy made to original block and it was made in 2016
I have all the NOS parts to complete the engine. As soon the engine is finish I will be getting the gearbox and fransfercase rebuild as I pull the top off with the gearstick from gearbox :shock: their was a lot of broken gear pieces on top of the shifter plate.
everything beginning rebuild, engine, gearbox and transfer case.


Cheers Peter

Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Wed Sep 13, 2017 2:58 am

Hi Gens
Next week my jeep will be home from farm and I will be working on new wiring under the dash board as its mess when I got it.
Will put correct gauges, fix brakes and brake lights switch, convert to 8 volt,

While working on the crack engine pulling apart, we also found 4 valves completed worn out badly as well.
the valve engine block is a no chance to be fix as it has few crack around it, so we are rebuilding a brand new repro engine exactly the same as original.

Cheers Peter

User avatar
Chuck Lutz
Gee Addict
Posts: 26829
Joined: Wed Jun 28, 2006 7:00 am
Location: Jeep Heaven

Re: Knocking and back firing when gas panel is down

Post by Chuck Lutz » Wed Sep 13, 2017 8:17 am

Many engine block cracks CAN be fixed....your problem was exacerbated by four burnt valves which only added to the problems. How about posting pics of the cracks in the block as some guys are very interested to see where the line between repairable and junk is being drawn.

Original blocks that CAN be repaired are highly sought after. The cost of the repairs is often not as bad as one might expect when the option is to buy a repop block or take a chance on another take-out block.
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947

Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Tue Jan 16, 2018 8:36 pm

Hi G club
I finally got my GPW engine fully rebuild and runs, I have post videos on YouTube
video here
https://www.youtube.com/watch?v=zyVGeT8GfzQ

Thanks

Peter

Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Mon Jan 29, 2018 12:55 am

Hi guys here's another video on YouTube of my jeep GPW engine running.
https://www.youtube.com/watch?v=x22iujxMPJs

Thanks
Cheers Peter

User avatar
Pat Walker
G-Colonel
G-Colonel
Posts: 1654
Joined: Fri Dec 13, 2002 2:50 pm
Location: Lincoln, CA
Contact:

Re: Knocking and back firing when gas panel is down

Post by Pat Walker » Sun Feb 11, 2018 8:10 am

So what was the problem with the GPW engine? I have a similar problem. I have narrowed it to a sticking exhaust valve. The stem and guide are so warn out exhaust gasses are blowing by and it expands and that valve sticks. I’m taking apart my engine this year and going to rebuild it. I thought it was weak springs and when I swapped them out one valve I had a hard time extracting. And that valve stem was warn.
It was last rebuild in the 1960’s.
42 GPW 82603 Matching serial Numbers
43 MB jeep salad
45 MB
45 MB
43 Bantam
45 Bantam
M101 canadian
Converto Dump

to many projects so little time
http://www.tacticalblunder.com/g503/sho ... &ppuser=62

Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Mon Feb 19, 2018 1:28 am

Hi pat
I have found my problem on the GPW engine.
When I strip the whole engine apart for rebuild, found out when my father told me the engine was rebuild in 2009.
Once the engine was completely strip found out all the valves were all worn and rusted, my father was so confused so he checked the parts that was left over from the engine mechanics back in 2009 he found the NOS valves in the box still, the bloody mechanics put the old rusty worn valves back in instead of puttin the NOS valve in.
So now my engine has all NOS parts in it and runs so sweet and strong.

Pat Your engine would have the same, worn out sticky valves, and so other parts as well . so it's best to rebuild the whole engine because you said the engine was since last rebuild in 1960.

Cheers Peter

User avatar
Chuck Lutz
Gee Addict
Posts: 26829
Joined: Wed Jun 28, 2006 7:00 am
Location: Jeep Heaven

Re: Knocking and back firing when gas panel is down

Post by Chuck Lutz » Mon Feb 19, 2018 8:34 am

Pat...just an FYI here....a COMPLETE rebuild should include new valves and valve guides and stellite inserts for the valve seats. I don't know if that is your problem but those are not really expensive additions to a proper rebuilt engine cost.
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947

Peterdodge6volt
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 362
Joined: Tue Apr 19, 2016 9:19 pm
Location: Australia

Re: Knocking and back firing when gas panel is down

Post by Peterdodge6volt » Thu Apr 12, 2018 2:09 pm

Ok
The fully rebuild engine is install in the jeep few days ago when for a test drive and suddenly it's started playing up again but no back firing, WHAT IS GOING ON :x :o,
I check coil was a bit hot.

There only 2 questions to ask.

Questions 1) Is there some kind of short somewhere, the generator was running funny screaming so disconnected nothing so far.
When bleedin the brakes yesterday my sister said is brake lights on and I said yes look at the amp gauges, amp gauges was going crazy, flickering on -50 and + 25/50 when engine off, blinker off as well, brake lights off.

Questions 2) my father thinks it's fuel blocked, it's runs fine for 5 minutes drive and then every 2 second runs, died,runs,died,runs,died,

Like before but no back firing.
I did smell fuel somewhere when installing the exhaust on passengers side, but no smell on driver side checked for leaks but no leaks.
So fuel line is blocked or not. Today will try with fuel rubber hose on can and test drive see how that's goes.

If still playing up then will put a wire from battery to coil and see how that's goes if no shorts.

OldPappy
G-Second Lieutenant
G-Second Lieutenant
Posts: 532
Joined: Wed Mar 28, 2018 4:22 pm
Location: USA - East Tennessee

Re: Knocking and back firing when gas panel is down

Post by OldPappy » Fri Apr 13, 2018 3:54 am

Just read through this long, and somewhat confusing thread. I don't know whether you have a rebuilt engine on the 2016 repro block, or a rebuilt engine on the original block, but there is enough conflicting information to justify the confusion.

Two things caught my attention, and may not have a thing to do with what you have going on but who knows at this point.

1) You started having problems after installing a reproduction carburetor, and 2) at more than one point you mentioned smelling fuel, and fuel in the oil.

This triggered a memory from 30 years ago.

I once installed a "remanufactured" carburetor in an old Firebird I had. The carburetor was cheap, and it ran great for a while, so I thought I got a good deal.

Then on a trip 100 miles from home it started running terrible, very rough, backfiring, missing, and underpowered. I thought at first I had gotten bad fuel, or maybe water in the fuel, but that wasn't it. I then thought it had jumped time, so I replaced the timing set, and that didn't fix it either.

It sat for a few days, and I noticed oil, thinned with gasoline, was leaking out of the dip stick tube. It was full up to the top of the tube!

I thought "fuel pump diaphragm", so replaced the fuel pump, drained the oil, and refilled. Same thing happened again.

The problem turned out to be the "remanufactured" carburetor. This was a four barrel carburetor, and two of the soft metal plugs in the drillings were missing, I assume they had fallen out, and were consumed. This was allowing raw fuel to be drawn into the engine to the point it filled the block. It is a wonder the thing didn't bend some rods due to hydraulics.

So, that cheap price on the carburetor, wasn't such a good deal after all.
A.C.Fults
East Tennessee
Shade Tree Mechanic more than 50 years.
None of us are as smart as we pretend to be.


Post Reply

Return to “MB GPW Technical Knowledge Base”

Who is online

Users browsing this forum: dinof, Henk, Rml1708 and 64 guests