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Waipio Rim · 07-26-2011, 09:17 PM

Can anybody recommend a good mechanic and/or rv service shop in the San Antonio area? Our '84 310 is parked at our son's place in Bulverde, and we want to get some work done on it before we go there in mid-November and drive east toward the next kid's house. The mechanical work will be oil, lube, and chasing down a vapor lock issue that we have been living with since we bought it about 5,000 miles ago. The coach service items are replacing batteries and converter, a roof vent, and maybe more stuff on the roof (replace front a/c unit, put a solar panel where the rear a/c unit is now) if I can afford it. Wanted to do some of this with our son when we get there, but he is scheduled to be working offshore so I want to pay somebody to do the work and spend some time with the grandson instead. Any suggestions will be appreciated.

87MH · 07-27-2011, 05:30 AM

Lots of threads on solution of vapor lock in these old MoHo's- just do a search on "vapor lock".

On these RV's it's a long way from the tank to the engine. The engine is trying to "suck" fuel all that distance through a 3/8" line and probably a couple of filters.

The 345's all had a secondary in line fuel pump installed at the fuel tank. Don't know if the 310's had this factory installed or not.

Would suggest you try adding a small fuel pump as close to the fuel tank as possible - pumps can be purchased for about $50.

Make sure you locate ALL of the filters and replace them (including the one inside of the carb). The 345 has a total of 3 filters (one of them hidden pretty well at the retractable step).

Waipio Rim · 07-27-2011, 12:10 PM

Thanks, will put filters on my list of stuff to do. Again.

I think that we are pretty far down the road on this vapor lock issue. Have the inline fuel pump, filters have been replaced, fuel line near header pipes has been wrapped. PO even had the tank removed and cleaned. Had the carb rebuilt at a shop near my mom's in Montana last winter, that gave us a significant mileage improvement but didn't help the vapor lock symptoms. From the way it behaves, seems like a heat sink issue in the carb, mechanical pump, or the lines around the motor. Next step is planned to be installing an insulating block under the carb and a cold air intake. Both are sitting in boxes at my son's in Bulverde but now he won't be around to do the hard work while I offer constructive criticism.

One thing this vehicle does that I don't think it should, and that I have not seen mentioned elsewhere: when I stop for gas and take off the gas cap, the tank inhales air and sometimes I can actually hear the sheet metal of the tank unbuckling. If I read the GM manual right, the tank is supposed to be vented so I would not expect this to happen. Comments?

**DKB_SATX** · 07-27-2011, 12:22 PM

Quote:

Originally Posted by Waipio Rim

Thanks, will put filters on my list of stuff to do. Again.

I think that we are pretty far down the road on this vapor lock issue. Have the inline fuel pump, filters have been replaced, fuel line near header pipes has been wrapped. PO even had the tank removed and cleaned. Had the carb rebuilt at a shop near my mom's in Montana last winter, that gave us a significant mileage improvement but didn't help the vapor lock symptoms. From the way it behaves, seems like a heat sink issue in the carb, mechanical pump, or the lines around the motor. Next step is planned to be installing an insulating block under the carb and a cold air intake. Both are sitting in boxes at my son's in Bulverde but now he won't be around to do the hard work while I offer constructive criticism.

One thing this vehicle does that I don't think it should, and that I have not seen mentioned elsewhere: when I stop for gas and take off the gas cap, the tank inhales air and sometimes I can actually hear the sheet metal of the tank unbuckling. If I read the GM manual right, the tank is supposed to be vented so I would not expect this to happen. Comments?

LOTS of older vehicles were particular about the gas cap. If you had a vented tank, you needed a non-vented gas cap, but some manufacturers used the cap to vent the system. From the symptoms you describe, you may simply need to find a properly vented gas cap. It sounds like you're planning to do some work before you do much driving, but a good test is to open the gas cap when you encounter the vapor-lock problem and see if that improves/eliminates the symptoms.

My dad used to tell a story about their '53 Chevy. My mom is frugal to a fault, and was probably among the first in Texas to go for self-serve gasoline to save a penny. At some point she lost the gas cap and went to a parts store to get a new one. She was given a non-vented cap, but it fit the filler neck.

They were going from Dallas to San Antonio and the car was running very poorly, starving for fuel, etc. My mechanic father was irritated because it had been trouble-free up until then and he'd kept up the maintenance. He also eventually realized that the fuel gauge hadn't moved much, but they'd covered lots of miles. They pulled in at a gas station, and he was going to see if he could put some gas in and figure out if the gauge was broken, etc. When he opened the gas cap, he heard that "sucking sound" and a clang from the tank, but the tank had been so deformed that it didn't fully return to its original shape and they lost a few gallons of fuel capacity. It ran perfectly well after that with a vented cap installed.

Xstream · 07-27-2011, 12:23 PM

Charcoal canister may be clogged.

Chasmorgan · 07-27-2011, 01:33 PM

Give Dan Bailey a call in Austin. He is a travelling RV guy that I've used and have been more than satisfied with his work. I'm not sure if he can help but its worth a phone call. He pulls a fully loaded RV repair shop trailer and is quite busy. His number is 512-970-9185.

Waipio Rim · 07-27-2011, 02:17 PM

Thanks all, appreciate the help.

lsmith · 01-18-2012, 07:54 PM

I would highly recommend Texas RV on Austin highway. Tony is the service manager and is very knowlegable.
They do it right

Waipio Rim · 01-18-2012, 08:47 PM

Charlie,

Thanks, I have Texas RV bookmarked for the next time we get to Texas. I will always need help with something. Made it as far as Knoxville in November, continuing east to our daughter's place in Delaware in March and at this rate will be back in San Antonio in about a year if all goes well. Put on a vented gas cap while in San Antonio and noticed a couple of stray gas lines coming from the tank that appear to be capped off. Still vapor locking when the engine is good and hot and fuel is not moving through the line fast, like after sitting at a stop light or coasting down a hill. First thing i will do when we get to Knoxville is verify that the PO's mechanic reinstalled a fuel return line when he worked on the tank.

slowmover · 01-20-2012, 05:30 PM

In line with this, which RV center has a very good selection/stock of RV parts in SA? I realized I may have to be up there and it behooves me to locate a good place to buy.

bwoodtx · 01-20-2012, 06:30 PM

Quote:

Originally Posted by REDNAX

In line with this, which RV center has a very good selection/stock of RV parts in SA? I realized I may have to be up there and it behooves me to locate a good place to buy.

I would again suggest Texas RV Supply on Austin Highway. Very, very few times have they been out of anything I needed.