Count down to kick-off

[PeterH-350LE]

Originally Posted by Gregsch

Good point!
What if these two events are related? When I sat on the side of the road thinking I was out of gas, it was in fact a hot ignition. Soo.. after sitting for 1 1/2 hour on the side of the road it cooled off and then restarted. The fact that I added 8 gallons of fuel had nothing to do with it.
Sure glad I did not drop the tank again!
Are these ignition modules suspect? That's what caused this kind of problem on my Ford.

Your plugs do not point to an ignition issues unless you cleaned them. They would have been black and sooty.

[bkahler]

I wouldn't say the ignition modules are a common failure but they do fail and they aren't the expensive. I would suggest replacing it with a new one and do some more test driving. If the problem doesn't re-occur that very likely wasn't your problem. If it doesn't solve the problem you will at least have a spare on hand for when it does eventually fail.

[Gregsch]

Replaced the rotor and the distributor cap along with the coil and the ignition module. All looked ok but, were suspect because they all looked very old, maybe 37 years old. No sign of the issue with it randomly stalling.. I think it was a bad ignition part. I did not try to run the tank below a quarter tank (having too much fun to mess around with that) but, I think I could if I wanted to. I will take a 5 gallon can of fuel with me next week and prove the theory.

Runs perfectly on the highway. Set the cruise on 60 mph and she rolls along effortlessly. About 350 miles , got 8.8 mpg

It still stumbles a little, off idle, but, I put some Lucas injector cleaner in the gas and that seems to be helping.

[PeterH-350LE]

Greg, just curious if you did check that internal filter at your carb inlet, I mentioned above. Most people have no clue that there is a filter, including myself. I had a very similar problem to yours with my first class C, sudden random stalling and the engine just stopping like there is no fuel. Then an hour later no problem. I finally found that filter to be the problem. Why its random, beats me, may have to do with certain fuel pressure and heat.

[Gregsch]

Originally Posted by PeterH-Airstreamer

Greg, just curious if you did check that internal filter at your carb inlet, I mentioned above. Most people have no clue that there is a filter, including myself. I had a very similar problem to yours with my first class C, sudden random stalling and the engine just stopping like there is no fuel. Then an hour later no problem. I finally found that filter to be the problem. Why its random, beats me, may have to do with certain fuel pressure and heat.

When I first got the MoHo 4 years ago I dropped the tank and replaced both the filters (the inline filter along the frame rail and the carb inlet filter) . Everything was spotless. That was only 1500 miles ago but, you make a good point. I will check it tonite. Thanks

[Gregsch]

Originally Posted by PeterH-Airstreamer

Greg, just curious if you did check that internal filter at your carb inlet, I mentioned above. Most people have no clue that there is a filter, including myself. I had a very similar problem to yours with my first class C, sudden random stalling and the engine just stopping like there is no fuel. Then an hour later no problem. I finally found that filter to be the problem. Why its random, beats me, may have to do with certain fuel pressure and heat.

Ok Peter, I took the fuel filter off at the carb inlet. Looking closely at the filter I notice it has a little rubber piece that appears to be a check valve. I pulled it out and found a little chuck of rubber ( reminds me of the hanging chads from the Presidential election a few years back) . Looks like the little chunk of rubber was the piece in the side of the check valve that should have been discarded at the factory. I removed it with a dental pick, it fell on the floor and disappeared.
Now my question is how is supposed to go back together? The brass nut that retains the filter has a thin nylon ring that seems to seal it at the carb body. The other end where the steel fuel line attaches looks like a flare fitting but, it has a little black rubber ring where the flair would seat. Is that supposed to be there? Should I be using a gasoline resistant sealer on the threads? Well you asked !

[PeterH-350LE]

Originally Posted by Gregsch

Ok Peter, I took the fuel filter off at the carb inlet. Looking closely at the filter I notice it has a little rubber piece that appears to be a check valve. I pulled it out and found a little chuck of rubber ( reminds me of the hanging chads from the Presidential election a few years back) . Looks like the little chunk of rubber was the piece in the side of the check valve that should have been discarded at the factory. I removed it with a dental pick, it fell on the floor and disappeared.
Now my question is how is supposed to go back together? The brass nut that retains the filter has a thin nylon ring that seems to seal it at the carb body. The other end where the steel fuel line attaches looks like a flare fitting but, it has a little black rubber ring where the flair would seat. Is that supposed to be there? Should I be using a gasoline resistant sealer on the threads? Well you asked !

Attachment 271580

You are not supposed to listen to whatever I may say
I would like to hear others input on this, but I completely removed that filter from my carburetors in the past and only used inline filters that were much easier to maintain.
I would use a gasoline resistant sealer along with the nylon ring.
But do you think that little piece of rubber could have caused some fuel delivery issues or even worse issues later ?

[Gregsch]

Yes I do. Could very well have been causing the problem. At this point I am concerned that I get it back together in such a fashion that it does not leak. I had a friend whose pick-up truck burnt to the ground a week after his mechanic rebuilt his carburetor. I have visions of ASTailgators Moho burning up. I have come way too far for that.

[PeterH-350LE]

Originally Posted by Gregsch

Yes I do. Could very well have been causing the problem. At this point I am concerned that I get it back together in such a fashion that it does not leak. I had a friend whose pick-up truck burnt to the ground a week after his mechanic rebuilt his carburetor. I have visions of ASTailgators Moho burning up. I have come way too far for that.

I hear you, I found a missing fuel hose clamp right above the exhaust and a leaking throttle body on my FI, so I can appreciate your concern.
But knowing your history of how you do things, I doubt you would even leave the driveway without having checked and doubled checked for leaks.
Still would like to get others input if that filter (and check valve) is better off in the junk pile

[Gregsch]

Agreed. Hopefully someone with experience with quadrajets will chime in with some sound advice.

[bkahler]

Greg, I just checked the two quadrajets I had sitting the shelf and they were both as shown in Peter's picture although one was missing the spring.

Brad

[Gregsch]

Tried to replace the fuel inlet nut this week. Parts guy ordered it but, when it came in it was too small. I would feel more comfortable with fresh seals on both ends. I will keep looking.
I could not get the back-check in the filter to work to my satisfaction so I just took it out and threw it away. Not sure why I need a back-check in the first place.
Noon kickoff tomorrow. I will find out in the morning.

[Gregsch]

Another successful trip. To the game and back 280 miles, 9.2 mpg. Took a 5 gallon can of gas with me so I felt confident to drive it until the gas gauge read empty. Sure enough , drove it until the gauge read empty then filled up. Put 30.5 gallons in. That seems about right. its a 40 gallon tank.

The stumbling off idle gets better by the mile. It is just a slight hesitation now.. I have been putting Lucas injector cleaner in the gas and it seems to be cleaning things out.

Now the bad, After it ran flawlessly for the 120 mile return trip it acted up again. When I got off the interstate I drove a couple miles through town and when I got to the edge of town and started to accelerate back to 55mph it stumbled and missed like it was running out of gas .. After about 30-45 seconds it started running again and I drove 6 more miles to home with no issues. At home in the drive I left the engine running so I could check the trans fluid. After a couple minutes I attempted to pull it up to the shop and it just died and would not restart. After about 30 minutes I started it back up and in ran flawlessly for a 10 minute drive???????

[bkahler]

Greg, does your coach have an electric fuel pump? I glanced back through a number of pages of your thread and didn't see any mention of one.

If there isn't one I'd suggest adding one and if there is one you might check to see if it's working properly. Your symptoms sound a lot like vapor lock.

[Waipio Rim]

If it is vapor lock, you might want to try insulating the hard fuel line that runs from the mechanical fuel pump to the carburetor. I went coast to coast and back fighting symptoms like yours. I could drive on the highway all day, but when I backed off the gas the fuel in that line would slow down and heat up. When I hit the gas again it was trying to run on bubbles, and would act like it was running out of gas until it worked the bubbles out. Put header wrap around that line, and the problem is gone.

[Gregsch]

Originally Posted by Waipio Rim

If it is vapor lock, you might want to try insulating the hard fuel line that runs from the mechanical fuel pump to the carburetor. I went coast to coast and back fighting symptoms like yours. I could drive on the highway all day, but when I backed off the gas the fuel in that line would slow down and heat up. When I hit the gas again it was trying to run on bubbles, and would act like it was running out of gas until it worked the bubbles out. Put header wrap around that line, and the problem is gone.

You and I are thinking alike at this point. It has to be 85 degrees or hotter to get it to do this. I generally try to drive before daybreak because I do not have dash air and the traffic is lighter that time of day. Driving 60 mph tends to annoy my fellow motorist. Header wrap aaahh!!!, on my way to the parts store.

Brad , I do not have any fuel pump besides the mechanical pump on the side of the engine. I was hoping I could stay away from adding an electric pump but, that may be my next move.
Thinking maybe I should join the Good Sam Club before I try to drive 500 miles to Memphis next Saturday

[jm2]

FWIW, our coach has a single electric fuel pump located on the drivers side (same side as fuel tank) that is then piped up and alongside the linkage side of the Quadrajet, then U-turns into a screw-in fuel filter at the carburetor body.

the mechanical pump removal and the electric pump installation was done by a PO, Dan.

we drove this coach from Los Angeles in late September in some warmish (90 degree plus) temps over the mountains to the Grand Canyon, then onward to the Albuquerque Balloon Fest.

after the baloon fest, we made our way back to the east coast, and we've never experienced anything that looks like a fuel problem in about 5,000 miles!

ymmv!

[bkahler]

Originally Posted by Gregsch

You and I are thinking alike at this point. It has to be 85 degrees or hotter to get it to do this. I generally try to drive before daybreak because I do not have dash air and the traffic is lighter that time of day. Driving 60 mph tends to annoy my fellow motorist. Header wrap aaahh!!!, on my way to the parts store.

Brad , I do not have any fuel pump besides the mechanical pump on the side of the engine. I was hoping I could stay away from adding an electric pump but, that may be my next move.
Thinking maybe I should join the Good Sam Club before I try to drive 500 miles to Memphis next Saturday

I believe the GM approved fix for vapor lock was to add the electric pump to the coaches. The overall installation of the pump is actually rather easy. One pump, one relay and some wire is about all you need to get the job done.

[bkahler]

Originally Posted by Gregsch

Thinking maybe I should join the Good Sam Club before I try to drive 500 miles to Memphis next Saturday

What route are you taking? I live near Richmond Kentucky just off of I-75, if you need anything along the way let me know

[Gregsch]

We will be taking I-75 to I-71 to I-65 to Bowling Green KY. Cannot pass up the opportunity to visit The National Corvette Museum. Then on to Memphis Friday night or Saturday Morning. 7:00 kick off.
Doesn't look like that is real close to you but, I do appreciate the offer.