Middle Jeep questions / problems

Started by GPster, August 18, 2011, 10:10:25 AM

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GPster

If I did it a line from the former PCV port would go to the back of the air cleaner That would put both ends of that line up high and level. Of course I could look for an old style oil fill cap with a vented/filtered fill cap. The PCV port is ill fitting and held together with a big glob of silicone and none of the hoses are correct. That and the PCV port on the carb points directly at the back port on the valve cover.I just don't want to spend my time working on a bad idea but I could make this fix easier than trying to be factory original. GPster


GPster

The picture on the last attachment is what I'm aiming for. I was mostly worried if maybe baffleing under the back outlet of the valve cover might make a problem. That rubber piece for the PCV valve outlet is a handy thing to have but I can see that the AMC PCV valve might be hard to find, it's plastic. I wonder how much difference there is in PVC valves other than body and fitting size and exterior design?. This weekend has been busy with Stern Wheel Festival and a car show and company and I've not been able to look at it for any more than a half hour a day. I think the company's leaving today so maybe tomorrow. GPster

GPster

Quote from: "wayne petty"Motormite/PCV Valve Grommet
For your 1980 Jeep CJ7 4.2L 2BL 6cyl    
Part Number: 42063
http://contentinfo.autozone.com/znetcs/product-info/en/US/drm/42063/image/4/
the PCV valve may be harder to get..
http://contentinfo.autozone.com/znetcs/product-info/en/US/chl/PC192/image/4/
Champ/PCV Valve
For your 1980 Jeep CJ7 4.2L 2BL 6cyl
Part Number: PC192  
I usually shop at Advance (1/2 mile away) but I figured if they couldn't come up with the parts they could use Auto Zone's numbers. I printed the images so I could remember what I was looking for. The copies must have been double sized because the parts they came up with were 1/2 the size of my pictures but the interchange was the same, so I took them. The last owner's fix must have been the quick method with whatever he had laying around and 1/2 a tube of silicone. Originally the glob of silicone looked to be the size of the hole to use a grommet the size of my double sized image but when I scrapped it off the parts by numbers fit perfectly. Now when I manufacture a hose to go from the air cleaner to the valve cover (or maybe Dorman makes one of those too) what's left might appear factory. I found a site that explained PVC vales to convince me to use the proper one. Now if i can find a site that explains why the fuel system uses a filter that returns some of the flow back to the gas tank. It doesn't seem to be a standard thing for year or engine. Some have a filter with two barbed fittings and some with three and the extra line goes back to the tank not to the vapor cannister. GPster

wayne petty

the return style filter uses a restriction at the small line right at the tank.. to limit the return flow...

this keeps the fuel circulating through the pump and avoids the dreaded VAPOR LOCK.  where the fuel at the pump has picked up enough engine heat  is starting to vaporize in the fuel line..   the pump cannot handle expanded vapor.. so the pump runs dry as does the carb.. leaving you with some fine words of encouragement toward your jeep..


a huge tip... that filter was used on a LOT of mopar products..  if you ever get a car that runs out of fuel when you try to drive faster than 25MPG. pinch off the return line from the filter.. see if the car works properly again.. i have fixed a LOT of mopars by installing a small clamp on the return line back by the tank..    with the line off the tank.. i open the clamp till i just get a tiny flow...   if i blocked it totally.. i would defeat the purpose .. the restrictors in the return line have failed letting most of the fuel back to the tank.. dropping the pressure at the carb to almost 0.. this is not enough pressure to push the volume of fuel needed  through the needle and seat to keep the float levels up..


hope this helps

oh.. the pump height setting is done with the engine off usually..

you can mess with the pump setting if you want..  by having the engine idling..   crack the throttle.. do you get an instant shot of fuel from the squirters.???

one thing..  if the metering rods are set to low.. you will get a lean backfire through the carb when you open the throttle..


lean back fires as i understand are caused by the lean fuel not burning off properly.. leaving a tiny amount with a slow burning flame that is still there at the end of the exhaust stroke when the intake opens..  fire and fresh fuel cause the pop out the carb..

GPster

No wonder Chrysler (who ever) ended up with AMC . AMC was already using their parts (that 2 barrel carb) so the had to use their technology (vapor lock stop). I'll have to crawl under the back end of this thing and check the lines. I know the tanks been dropped and the skid-plate is new so there's no telling if that restricter jet is still in the return line. Although that carb now has a new needle and seat I probably won't push it. Of course being this Jeep was considered for all sorts of manuvers so it's got up-side down valves. To think I wanted something like this thinking it was simple and it suited me because it had an automatic transmission and power steering. This thing has been licensed and insured since I bought it and you can still count in feet how far it's moved under it's own power. Of course I thought maybe I'd drive it to the next Crosley build day and that hasn't happened either. GPster