Weber fuel pressure regulator question

GTSSportCoupe · Post by **GTSSportCoupe** » Fri Mar 24, 2006 3:53 pm

Hey guys, not sure if someone can help or not. Basically I'm trying to source a 4psi fuel pressure regulator to go with my Weber 32/36 DGEV. The tercel's fuel pump/pressure regulator feeds about 7psi into the Weber, but the Weber is designed to only run about 3-3.5psi. I understand that the 7psi can damage seals etc. after a period of time.

This fuel pressure regulator here looks suitable to me:
http://cgi.ebay.com/ebaymotors/Redline- ... enameZWDVW

Think it would work? Any ideas?

Nick

Mac · Post by **Mac** » Fri Mar 24, 2006 5:01 pm

I dunno how damaging it would be..

the pump supplies fuel to the carb and the float raises up and down, when it goes up it plugs the hole and makes the fuel bypass the carb and go back to the tank.

the only thing that could potentially be damaged is the needle that the float controls

GTSSportCoupe · Post by **GTSSportCoupe** » Fri Mar 24, 2006 5:38 pm

Mac wrote:I dunno how damaging it would be..

the pump supplies fuel to the carb and the float raises up and down, when it goes up it plugs the hole and makes the fuel bypass the carb and go back to the tank.

the only thing that could potentially be damaged is the needle that the float controls

I originally thought this too. I've just recently read that Weber Redline HIGHLY recommends only 3-3.5psi for the carb. They say that it'll damage seals after a while otherwise. For $35 it's probably worth just installing one.

shogun · Post by **shogun** » Fri Mar 24, 2006 5:41 pm

i use a carter fuel pump, an electrical one, and it pushes 4.5 psi ant 76gph and gave me no trouble with the 48 ida, too bad it was too much carb in that engine

zipty842 · Post by **zipty842** » Fri Mar 24, 2006 8:00 pm

A pressure regulator will also cut volume, which is what a weber really needs. Also, mechanical fuel pumps pulsate when they pumpand webers work best with constant pressure.

GTSSportCoupe · Post by **GTSSportCoupe** » Fri Mar 24, 2006 10:39 pm

zipty842 wrote:A pressure regulator will also cut volume, which is what a weber really needs. Also, mechanical fuel pumps pulsate when they pumpand webers work best with constant pressure.

Hmmm...so you're saying I'd be best off just installing an electric pump and regulator? Or...maybe less volume = better fuel economy? Means the engine might lean out a bit, but thats ok, I think it's running a little on the rich side anyhow.

zipty842 · Post by **zipty842** » Fri Mar 24, 2006 11:47 pm

actually, the carter pump noted above without a regulator is the recommended pump for webers. filling the float bowl at a slower rate isnt gonna use any less fuel either, because the rate of fuel consumption is based on vacuum pull through the carb.

Typrus · Post by **Typrus** » Sat Mar 25, 2006 12:44 am

Less pressure really doesn't mean less volume....
At any rate, if there were a pressure regulator, I'd imagine it would smooth out the pulses significantly?
It will leak with too much pressure. Someone on here with one noted seeing that.

zipty842 · Post by **zipty842** » Sat Mar 25, 2006 12:59 am

basically the way a pressure regulator works is by making the fuel line smaller here is a good source for weber info http://www.racetep.com/webtechpage.html

i will note that my dad has used webers for years with the factory toyota fuel pumps with out any problems. on models ranging from starlets to 4wd pickups.

shogun · Post by **shogun** » Sat Mar 25, 2006 8:45 am

as far as racing goes, the carter was the answer, by 7 out of ten racers and tuners i asked, and ill take flow any day before pressure

GTSSportCoupe · Post by **GTSSportCoupe** » Sat Mar 25, 2006 9:13 am

Thanks for all the advice guys. I'm really not a carb knowledgable person, I'm more of an efi type guy. OK, so I'm basically best off buying the carter pump that shogun uses, and not buying a regulator at all? I think I'll look into this. Thanks again!

Typrus · Post by **Typrus** » Sat Mar 25, 2006 11:42 am

If you're going to buy one, here is what Weber recommends. http://www.racetep.com/webfuelspark.html#webfuel

GTSSportCoupe · Post by **GTSSportCoupe** » Sat Mar 25, 2006 10:07 pm

Typrus wrote:If you're going to buy one, here is what Weber recommends. http://www.racetep.com/webfuelspark.html#webfuel

Good link Typrus; thanks! I'll look into that. It think that is definitely the way I should go. Sounds like the tercel's fuel pump is a POS as far as webers are concerned. I'll be interested to see how this affects fuel economy.

takza · Post by **takza** » Sun Mar 26, 2006 3:31 am

Too much pressure can overload the float controlled valve...causing periods of high fuel levels? This would cause excess fuel use during idle and cruise?

GTSSportCoupe · Post by **GTSSportCoupe** » Sun Mar 26, 2006 10:45 am

takza wrote:Too much pressure can overload the float controlled valve...causing periods of high fuel levels? This would cause excess fuel use during idle and cruise?

Thats sort of along the lines I was thinking. Course as I mentioned, I really don't know much about carbs. Ah well, we'll see what happens I guess. Once I have the MR2 on the road 100%, then I'll pull the terc aside and do some work on it (including this fuel issue).