Fuel tank not delivering.

CapnDirk · September 04, 2016, 05:38 PM

1988 Itaska Suncruiser.

Purchased a fixer upper, and have been a mechanic of one sort or another for 40 years. Drove the RV home after purchase 100 miles. Went to start it a few days later, and was pouring gas on the ground. Pinhole at electric fuel pump hose behind batteries (in step) Replaced both in and out lines. Tried to start again, gas hitting the ground, replaced 4 inch section a foot forward of batteries. Tried to start, no gas reaching carb. Pulled incoming line for electric pump and put in a portable tank, engine fired up.

As I understand there may be another pump in the tank on this model (85-89 P30) I have the coach batteries out to replace, but would not think GM would have powered the tank off the coach batteries. I got under the RV to take a look in the tank area, for a wire, but not enough room over tank to see anything. Where it gets a bit wonky, is that I found the pressure regulator peeking through a hole in the side of the frame but there is a fitting pointing forward, but fitting and whatever was hooked up to it pointing rearward is gone. I know that's not right, but what baffles me is that it ran and drove before blowing holes in the old fuel lines.

Any suggestions on where to hunt would be appreciated. I have other things to address, but will be going at it one system at a time.

Thanks.
Dirk

MotorPro · September 04, 2016, 07:20 PM

The fitting pointing to the back of the regulator is a second out. The inlet is on the back. Opposite the Allen head adjustment screw.

CapnDirk · September 04, 2016, 08:42 PM

Thanks, I take it that the second out would have a plug in it? The ones I saw on Ebay did not show the back. Soooo, one less hack to worry about.

Just seems too coincidental that the tank (if it has one) pump would give out at the same time I replaced bad hoses. I did pressurize the tank with some air to see if it would prime, but no change. The only thing that has changed was that the coach batteries are out to get to the fuel pump behind them and change hoses. Another note that concerns me is that that same pump runs even in ACC. position on the key. So listening to the stereo would have the pump running continuously.

Dirk

Rickf1985 · September 05, 2016, 09:30 PM

If the pump is running continuously then someone has bypassed the relay. The relay is usually mounted in the engine compartment on the drivers side about where your right leg would be. These relays have not been made for years so a lot of people instead of making up a new relay system will bypass them to run whenever the ignition is on. Your PO may have gone with a wire that was also hot with ACC. You might need to check to be sure they at least used a relay. As far as not getting gas to the pump check for any other rubber lines before the pump that you have not replaced and replace them because they may be internally collapsed.

CapnDirk · September 06, 2016, 02:05 PM

Thanks Rick. I did realize after more reading that there would have to be a pump in the tank, as there would be no need for a regulator (stock Holly on frame) if there was none. So, I have three fuel pumps. In tank, carter electric half way to engine, engine mechanical.

A discussion with friends last night and previous readings (short hose from in tank pump to metal fuel line above it cracking) resulted in the decision to drop the tank, and replace all lines including the likely rotted gen. lines as well as the in tank pump. All things considered, cheep insurance to avoid going down the road on fire like a scene from road warrior.

Not looking forward to dropping an 80 gallon hot water heater laying sideways partially filled.

Dirk

Already ordered rebuild stuff for the Holly pressure reg. anyone know what fuel pump to order?

Thanks.

BrianB · September 06, 2016, 03:01 PM

How to drop the fuel tank:

1. Build up wooden blocking (scrap pieces of 4x4 and 2x4, 6x6 if you have it) leaving an inch or so between the blocking and the tank.

2. Remove the 4 bolts (2 front, 2 back) holding the tank flange to the cross members.

3. Loosen and remove the straps.

4. Use a jack to lift each end in turn and lower the tank the thickness of a 2x4 at a time. A rolling "Nascar-style" jack is good for this.

5. When you get lower than the jack can get you, just knock the blocks over on back end and let it fall to the ground (it's maybe 6 inches at that point).

6. Reach up onto top of tank and disconnect wire pack and source/return/vent rubber lines.

7. Pull the tank back off the front blocks and slide it out from under the RV. You should be able to clear the side of the RV without jacking it up.

This process can be done by yourself (I did, with about 15 gallons in the 70 gallon tank) but is easier with a helper.

CapnDirk · September 07, 2016, 11:20 AM

Thanks Brian.

Weather here is suppose to be back up to 80 on Friday, and rebuild kit for pressure reg here on Friday as well. Any idea what to ask for at the parts store for a fuel pump?

Rickf1985 · September 07, 2016, 01:03 PM

You did not mention the fill and vent tubes which on mine are almost impossible to see let alone get to over the passenger side frame rail and behind the storage bins.

BrianB · September 07, 2016, 04:14 PM

You're correct - I forgot to mention those. You should be able to get a long screwdriver (or 1/4" nut driver) in between the tank and frame rail to undo the clamps holding the hoses to the neck on the tank.

CapnDirk · September 07, 2016, 09:27 PM

Thanks guys.

The hose to the pres. reg looks like it will allow the tank to drop a bit, any idea how much slack in the others?

I plan on replacing that slip nut hose to the reg, is the one going forward from the reg. the same 1/2 fuel line hose I've come to love?

When I figure out how to post pics, I'll post some of the old fuel lines. I'm sure you'll agree "this guy made it 100 miles?"

BrianB · September 07, 2016, 09:36 PM

Regarding the hose from the tank to the regulator, take a look at this thread: http://www.classicwinnebagos.com/forum/index.php/topic,12390.msg73326.html#msg73326

It is metric M14x1.5 on both ends (female on the rubber, male on the hard line), and should be fitted to the regulator with a brass adaptor.

Be careful when removing the adaptor from the regulator. You can't buy them anymore.

CapnDirk · September 07, 2016, 11:18 PM

Thanks for that heads up. never would have guessed it was metric. Been turning a wrench for 40 years, and I remember how it drove us nuts when they started to go metric here in the states. Didn't know if it was metric or SAE without asking someone ore having to look it up. And I swear we ran into stuff that was SAE on one end and metric on the other

I planed on having the local hydraulic shop make it, but will probably now have to chop off the ends so they can.

Again, thanks for the heads up, more than one person would have ended up scratching their head on that one.