This is.... !! I spent the day in the garage routing fuel lines only to come up with this. Parts > Mr Gasket 7 1/2 psi micro fuel pump > Road Demon 525 > Generic regulator with return style port, one in two outs > Generic pressure gauge So I tried to hook up the return line and I got a nice 3 psi of pressure, no go. Plugged the port to the return line ( is that wrong? ) and just had the fule pump go in one port of the regulator and out another. I was able to notch it down to 7 1/2 psi as it seems this fuel pump wants to put out 12psi. I tested it with a separage guage to be sure, yep its 12. The regulator was doing fine so I started a test drive through the apartments and on the way to the road I almost died over a spead bump. Bad sign... Pulled over, shut off the engine and checked under the hood. The clear fuel filter was empty, normally its full. There was still fuel visable in the carb through the sites so something must have just happened. I turned the key on but didnt crank the engine so the fuel pump would turn on. The clear filter filled up with gas slightly so I just headed back up to the garage. Popped the hood there and looked around for about five seconds when the freaking regulator started spraying GAS!! AT THE ALTERNATOR! AND FAN!! OMG! Cut the engine and clamped the line called it a freaking day.... Just when I think I might have got everything tuned right, the whole thing almost goes up in flames. I dont think I'm going to cheap out on a regulator. Not sure why the bypass only gives me 3psi so I have to go straight to the carb like this... Can anyone recommend a good setup? I'm just tired of piecing these turds together. I dont care what it might cost, I just dont want to set my car on fire. Infact... I might just incase these risky parts in a custom box just incase it decides to freak out on me. I can have the box go through the return line to drain safely incase... This was just a bit scary. just a bunch of

This is the modem that spray from the top just under the nut you would loosen to turn the adjustment bolt. There is a lil notch in the metal under the nut that looks like where it is designed to spray if overloaded or of the diaphragm broke. I'll never trust this type again!

Note: I have removed the old pic and uploaded this new one because the old one was just some random google search pic. Who ever's pic it was, they used some type of line from home depot rather than a proper fuel line. Sorry for the confusion.

That's not fuel hose you're using there, hydrocarbons...being it fuel, kerosine or even air tool lube will harden that type of line over time and it WILL crack. Replace that!!!

My first thought is that your diaphragm is broken. I'm also concerned about your plugging the return line. On my regulator the return line is needed to prevent pressure buildup inside the regulator. The pump is trying to send fuel at 12psi, and unless you give it somewhere to go it's going to go through anything that can't hold the 12psi. Also, what TT said, get that hose replaced with something proper before you try to run your pump.

1) did you replace the in-tank pump with carb pickup? if not, the new electric pump will die soon trying to pull fuel through a dead in-tank pump.

2) I hope the intank pump is not still functioning in addition to this mini pump you rigged outside the tank, cause the intank pump puts out well over 12 psi anyway.

3) if you have a carb pickup in the tank, why not just run a mechanical pump on the block and solve the regulator issue

4)there are only a few "return-style" regulators available in the world, and that does not look like one of them - just because they have more than one port doesn't mean they are return style - there's no cheap way around it - all the return style regulators are expensive - get a Mallory 4309. There's one for sale in the classifieds on here - brand new they go for $90 at Summit.

Lol sharp eye but thats not actually my pump. You are right, that looks like a water line hose that you would find at home depot. I just pulled a similar pic off of a google search. I only use fuel lines protected with a braided sleeve. Sorry about the confusion there, I would never use a line like that.

Isn't the point of a regulator to lower fuel pressure? So you can take your 12psi down to 7 1/2 ? What about the inline pumps that have no return line. Pressure goes to them, they relieve some psi and I guess the pump just keeps pushing though it only holds the pressure in the line between its output and the regulator's input. I'm not sure if this is bad for the pump... or if they are designed to take that type of abuse.

I do wonder if after I shut the engine off, will the pressure hold up and continue to press on the regulator and if that is ok. I would love to use the return line but I cant run my carb at 3psi. I wonder if there is something else going on with this setup to cause that. Maybe the intank pump and how its designed to push gas through the lines.

1> This thread made me wonder about that. The old in tank's 12v has been disconnected and routed to the new pump that is mounted under the car. Now that you mention it I can see how the external is pulling through the in tank pump. While it would make sense that this causes extra wear and tear on the external pump, I haven't heard of to many people having to drop their tanks to correct the in tank pump setup when they go with a carb. Are you saying this is a standard task to do and that everyone who hasn't done so will burn up their new pump? I'm just trying to avoid dropping the tank cause everyone says its a serious pain that they will never do again.

2> Oh no, I was sure to disconnect the power going to the intank pump. Running two pumps when your goal is to lower fuel pressure put out by the original efi system just seems kinda... dumb

3> I was looking at the mechanical pumps wondering the same though I did not know about this carb pick up in the tank. My next step is to research the differences between these intank pickups and the possible pumps that can be put in there to see what the cause and effect is when running different types of setups.

4> Well that answers the whole 3psi question. The dude who sold this to me at some speed shop probably didn't understand what I was trying to do. This regulator pretty much has an open T shape inside of it where gas goes in the bottom and splits left and right to the top with even flow. Taking the least resistance, I'm sure it was just dumping the fuel back into the tank and this is why the fuel going to the carb was only 3psi. Your correct, this is not a return style regulator and is infact the wrong part for my car.

http://www.summitracing.com/parts/HL...3/?image=large

Recent changes

> Removed old regulator, found a bad diaphragm Not sure if its truly a return style or not due to sites like this http://www.jegs.com/i/Holley/510/12-803BP/10002/-1

> Installed a Mr Gasket disc type regulator. One in and one out. It was just cheap and available, worth a try. The pressure going to the carb has lowered to 8psi as this was all that the regulator could do for me at its max resistance.

> Bought a freaking fire extinguisher! lol.. better safe than sorry

Current question / topic

Ok so I have the intank pump still in there as is, I never dropped the tank. Split into the line outside of the tank I have mounted a Mr Gasket Mini pump that is rated at 8psi but seems to put out 12. Is this pump actually pulling gas through the old intank dead pump and is that a huge problem? I was not aware that a carb conversion would most certainly require me to drop the tank. I still want to get a better regulator than the Mr Gasket because honestly these things just make me nervous. This should really be a simple task but I think I might just have the wrong parts. I saw one once that was designed to use your stock efi pump to the regulator that would output the proper psi to a carb. Maybe the Mallory is designed to do that, I'm looking into it. Also trying to find that regulator that said it would drop the psi quite a bit. If that's the case I wouldnt mind hooking up the old in tank pump and just running the proper regulator.

I'm still using my stock (1991 TBI) pump. It has a Mallory 4309 sitting in front of it and works just great. I've never hooked up the vacuum port on the regulator, and am not sure what benefit I would see if I did.

Those two things are not the same product. One is the 12-803. The other is the 12-803 BP. I'm guessing the BP stands for ByPass. The first one you listed has two ports, the second one, which costs twice as much, has a third port on the bottom (see the additional pictures). So, for $30 you get an inline regulator, which may well be the same casting as the return regulator without the return port drilled and tapped (please don't try to do this yourself) and for $60, you get a third port out the bottom, which happens to be the return line.

Sweet, that is just what I'm looking for and sounds like the best. safest and just right way to do it. I went ahead and just ordered the Mallory 4309 after I'm hearing that it can be used with the stock pump from your comment and one on the Jeg's description. This should square it away. Thanks for the help dude.

No problem. I don't know if it would work for the TPI guys because I don't know their fuel pressures, but I'm sure that if it didn't, another regulator would work. Not all I need is for people to start answering my threads.

A 4309 is fine for dropping the pressure of a TPI system down to the 4-7 psi a carb needs.

Anyone know what the fuel pressure is for a standard TBI and a TPI? My bird came with the TBI.

The new news sucks! I wired up the old pump only to find that its now dead. Not sure if letting it sit for 2 1/2 years on e did that or if testing with a new fuel pump did that. Looks like I'll have to wire up the external anyway until I feel like dropping the tank. Are we sure that pulling gas out of the old pump is seriously bad for the new pump? I mean if I open up the "sending" fuel line it seems that it will just spray gas forever. This kind of tells me that the pump wouldn't really have to much resistance pulling gas out of the tank. As a precaution I might just setup a visible fuel pressure gauge. I hear that someone has done this with somewhat of a trap that only allows pressure to be passed through rather than fuel so it was safe to run that line anywhere you wanted the gauge to be. A cut out on the power bulge hood would be cool. This way if pressure drops from the pump, I'll notice and have enough gas in the carb to safely pull over. Lol This is making me paranoid... thinking things like installing a secondary fuel pump rigged to a switch that would never really be used unless the 1st one died but.. yeah thats going to far. Dropping the tank should come before that... though I have two externals and a mountable switch

Meanwhile!... I'm going to look up a walk through on how to drop the tank just to see what all is involved in replacing the stock intank pump.

Installed the new Mallory reg and... it pulses? I was a bit surprised to hear it ticking and watching the guage pulse between 6 1\2 psi and 8. The thing has 5 total ports. The old reg didnt tick before it blew its gasket. Here is how I have the new one hooked it up, am I doing something wrong here? Didn't opt to use the vac port...

1. Bottom port labeled return is going to the return line
2. Side has fuel line from external pump
3. side goes to carb
4. Side has a pressure guage
5. Side is plugged

The engine seems to run just fine and after awhile the fuel filter between the carb and reg fills up full. That tick is bugging me though... thats not supposed to be normal is it?

I forget what it was but, mine pulsed too. I wiggled it around for a bit and the pulsing went away. I don't think it is supposed to do that, but it seems a common issue. You might try calling Mallory and seeing what they say.