Fuel Delivery Issue

[bluebird]

Gotcha. That one sits close to the back end of the tank on the drivers side. How about this thing, is it the regulator?

Also, should i just get rid of the ancient filter?

That's the regulator. I believe I'd just replace the thing if it were mine, they don't cost that much. Set the fuel pressure at 6 psi at the carb. Don't look like it has been hooked up for a while. I'd also put it were you can get to it easy. With the ethanol in the fuel now days the diaphragms don't tend to last long like they used to. They only last about 2 years on my race cars, BUT I was running E85. 


You might try and remove the screws to see if they come out without stripping before ordering anything. I would also install a new fuel filter where it can be changed easily in the future as you will most likely be changing it often. The tank does look like you have made huge improvements but don't know if getting all the rust out.

[legomybago]

Your getting her sorted out now. Good job. Remember, replace all the rubber fuel line you come in contact with.

[solracem]

That's the regulator. I believe I'd just replace the thing if it were mine, they don't cost that much. Set the fuel pressure at 6 psi at the carb. Don't look like it has been hooked up for a while. I'd also put it were you can get to it easy. With the ethanol in the fuel now days the diaphragms don't tend to last long like they used to. They only last about 2 years on my race cars, BUT I was running E85.

Yep, already bought that replacement from the link above as well as a gauge to keep on it. When you say 6 psi at the carb, what does that mean?

[solracem]

Your getting her sorted out now. Good job. Remember, replace all the rubber fuel line you come in contact with.

Thank you!! And yes, I'm definitely taking that advice and doing so. Hopefully I'll have her ready before the end of the month.

[bluebird]

Thank you!! And yes, I'm definitely taking that advice and doing so. Hopefully I'll have her ready before the end of the month.

Depends on where you put the gauge. Are you going to leave it on all the time?  If you put the gauge by the carb set the regulator to have 6 psi at the carb. I personally wouldn't leave the gauge on all the time. The cheaper gauges don't tend to last very long when left on.


If you have it on the rear, before your mechanical pump you may want to set it at 7 psi, as you will lose a bit going through the pump.

[Rickf1985]

WOW! an accessible regulator! That does not happen very often, usually they are in some god awful place. Mine actually had a structural brace right against the top of it, had to cut a compartment to see it and a mount to get to it. For thirty bucks I would just replace the whole thing, and especially replace that old rubber line. I would bet the problem was the fact it was not even hooked up, you were probably getting 15-20 lbs. at the carb!

And if that "filter" is on the line venting out the back leave it there because it is a check valve not a filter. It will let vapor pass but not liquid. If you took it out then every time you went up a hill or jump on the gas with a full tank you would leave a trail of gas behind you.

[solracem]

Depends on where you put the gauge. Are you going to leave it on all the time?  If you put the gauge by the carb set the regulator to have 6 psi at the carb. I personally wouldn't leave the gauge on all the time. The cheaper gauges don't tend to last very long when left on.

Gotcha, I was going to hook up the gauge right next to the regulator. But, what your saying is that I should hook up the gauge away from the back end of the vehicle and get it as close to the carb as I can. Then remove once I know the pressure is correct at the carb?

Should I move both the regulator and the pressure gauge closer to the carb? Or just have the pressure gauge wired in close to the carb for testing then remove?

[Rickf1985]

Get an electric gauge with a transducer and then you can put the gauge inside with you. They also last a long time. You want the regulator back where it is now at the tank.

[bluebird]

Gotcha, I was going to hook up the gauge right next to the regulator. But, what your saying is that I should hook up the gauge away from the back end of the vehicle and get it as close to the carb as I can and then remove once I know the pressure is correct at the carb?

Should I move both the regulator and the pressure gauge? Or just have the pressure gauge wired in close to the carb for testing then remove?

I'd put the regulator back by the tank, but where you can get to it after the tank is back up.


Ricks idea is a good one ! That way you'll know if you have a problem in the future.

[Rickf1985]

Once you set the pressure, and it may already be set right out of the box, you will not have to do it again so you really do not "Have" to have a gauge.

[DaveVA78Chieftain]

On an 85 1/2 to 89 chassis, the electric pump (13psi I think) is used to push the fuel up to the mechanical pump on the engine.
There should be a pickup "sock" on the electric pump.  The one on yours looks plugged up.  I think you can buy replacement socks.  They normally come with a new pump.
The electric pump to mechanical pump pressurized fuel line has a a regulator and a fuel filter in it.
The regulator (you show a pic of it) is normally mounted on the passenger side frame rail by the rear wheel.
Because the electric pump is just used to push fuel to the mechanical pump, the manual says the regulator should be adjusted to 5psi measured at the carburetor (5psi max/26 gals per minute). Page 7-49 (pdf page 144) of the Chevy Motorhome Service Guide (Download from the member area).
Place any fuel pressure monitor at the carburetor.  That is the key reference point.
The fuel filter is normally mounted 1/2 way down the passenger side frame rail (between front/rear wheels)

http://www.gmpartseast.com/Page_Product/PartList.aspx?MakeUrl=chevy&CatalogUrl=1988-p30&ComponentCode=TP0328401&SectionCode=03&EngineCode=LE8&TransmissionCode=M40&ModelCode=&Vin=&ProductionDate=&VehicleInfo=&CatalogCode=52P&Year=




POR-15 makes a fuel tank sealer kit.  Will take at least 2 kits to for this size tank.  Prevents internal rust build up

Make sure you clean out the rust in the metal fuel line from tank to mechanical pump also

Dave

[Rickf1985]

5 PSI is max pressure for an Edelbrock so make sure you don't go above that. If you are measuring the pressure with the engine running then you will also be measuring the pressure from the mechanical pump. The mechanical pump will put out from 3 1/2 -5lbs so it will be tough to see what the electric is putting out. The electric pump will run for two or three seconds when you turn the key on, this is not really enough time to see what the pressure is but the whole idea of the electric pump is to keep pressure in the line and keep gas moving towards the mechanical pump so if it is putting out 2-3 lbs in those couple seconds then it is good as long as it does not go above 5 when running. The regulator is most likely set for 3-5 lbs. since this is standard for a carburetor.

[M & J]

Welcome home Dave.

[solracem]

Looks like it could be some sort of check valve too/also? ?? Holy smokeys. Pull that thing off there and show us

legomybago - here are a couple of pics of the filter/valve thing. If you take a look at the diagrams I labeled above, you can see that it is the same hose as the one labeled #5. Also, you can see that it runs to the bumper as a vent tube.

i?? Does this help to identify what it is?

Also, attached is another picture of the regulator, It seems to have been plugged in as it was hooked up to hose #1

[solracem]

Well everyone, as promised, I believe I've FOUND THE PROBLEM and have loaded some pics.

I'm surprised it even ran actually... 

i?? Anyone have suggestions on how to go about cleaning the gunk and rust out? Or a suggestions on a replacement tank?

Hey everyone, so here are a few pics of the tank clean now. Should I put it back on like this and just make sure to keep it full/clean or should I use something like red cote or por-15 to treat it before putting back on? I've never used red cote or por-15 so I'm wondering if it's easy or if I should have it done by someone else (assuming it's needed... I hope not)

[Rickf1985]

With today's ethanol fuels it would be best to either coat it yourself or have it done. That is a big tank to be horsing around and to fully coat it you have to continuously be rotating it to get the coating to all parts of the inside. I'll let you decide on that one. But with all that bare metal in there you will get rust again no matter how much you try to keep moisture out, it is just the nature of alcohol to absorb moisture from the air.

[legomybago]

And if that "filter" is on the line venting out the back leave it there because it is a check valve not a filter. It will let vapor pass but not liquid. If you took it out then every time you went up a hill or jump on the gas with a full tank you would leave a trail of gas behind you.

[solracem]

Ah, thank you!! Must have overlooked that previously. Thanks for pointing it out

[legomybago]

I wouldn't be afraid of putting that tank back in right now....keep it full of fuel at all times..

[Rickf1985]

As fuel drops air enters, air has moisture. Nice hot day, hot roads, at night when you are sitting and things cool off the fuel contracts and pulls cool moist air into the tank. More moisture. It does not take long at all to get some water on the bottom of the tank, All tanks that big have a little water in them. Water will rust the whole inside of the tank and it will look just like it did or probably worse because at one time in the past it was coated, now it has been stripped bare.
And it is kind of hard to keep full at all times when you get 6 MPG! W% W%

[solracem]

As fuel drops air enters, air has moisture. Nice hot day, hot roads, at night when you are sitting and things cool off the fuel contracts and pulls cool moist air into the tank. More moisture. It does not take long at all to get some water on the bottom of the tank, All tanks that big have a little water in them. Water will rust the whole inside of the tank and it will look just like it did or probably worse because at one time in the past it was coated, now it has been stripped bare.
And it is kind of hard to keep full at all times when you get 6 MPG! W% W%

Yeah, that makes sense. The radiator services shop that I took it too said it's still in good shape and has plenty more years of use in it. However, they did recover more than 3 gallons of this gunk/mess from it.

I'm trying to conserve cash and may need to come back to the tank sealing since it's not necessary just yet. That or maybe just seal the top 1/4 of it?

[Froggy1936]

Its hard to believe that they got that much material out of it and there are no thin spots. I would definatly use the POR sealer and do the whole tank Especially the bottom where most of the material came from . The cost of the sealer is immaterial as opposed to having a leak in the bottom or doing it all over again . The only consideration is sealer cost VS new tank !  Frank P.S. that is a big one !

[Rickf1985]

That is engine block rust! Somebody has been running straight water, no antifreeze. Bad, bad, idea. Be prepared for the possibility of leaking freeze plugs.

My bad, I saw radiator shop and I thought you meant that came out of the radiator. I will leave to above there just so people know not to run straight water in the radiator.

[Rickf1985]

No comment

[M & J]

LOL @ Rick.