I am in the process of hooking up my fuel regulator/pressure gauge that I received from LCE engineering. I have them hooked up correctly, I believe from the fuel pump to the carb, but I am only getting 1 1/2 psi. This does not change with any adjustment to the regulator. I called a tech at LCE and he believes it is possible that the fuel return line and line to the charcoal can is misconfigured. Not sure how that can be because I have had the truck 7 years and it is the same configuration as when I got it. Here are some pics.


So above shows the line from the fuel pump tube closest to the manifold to the carb with the regulator/gauge in between.




Here you can see the top tube on the fuel pump, which was marked "IN", goes directly to the charcoal canister.




And the middle tube on the fuel pump goes directly to the gas tank.



Again, other than inserting the new regulator/gauge, the fuel regulator hoses are configured the same as it has been since I bought it.

Can anyone add some insight to this problem so I can get my 3.5 to 4 psi pressure to my carb?

 

I am not able to find any diagrams online showing the normal hookup to the fuel pump. I guess my immediate question is this. Does the fuel return line go directly to the gas tank, or does it have the charcoal canister inline? Right now, the charcoal canister is inline from the gas tank to the "IN" input on the fuel pump. If it is correct that way, I suppose I could have a bad diaphragm in the fuel pump that is not allowing enough pressure to the carb. I removed the fuel regulater temporarily to check the pressure from the fuel pump to the carb. It is showing about 1 1/2 psi. I pinched the return hose to block return flow with some pliers and the gauge reading was just over 5 psi. When I released it, I returned to about 1 1/2 psi to the carb.

Any help with this issue would be greatly appreciated.

 

Are you calling your fuel filter the Charcoal Canister??

Why do you need a fuel pressure regulator??

Not sure just what your trying to do here.

But a pressure gauge should be on the pressure side of the pump to measure the pressure going to the carb.

the 3 fuel pump connections.

You have the fuel in which would come direct from the fuel filter.

you then have the return line going to the tank.

you have the supply line going to the carb.

 

Thanks for your reply. Yes, that is a fuel filter. The tech I was in touch with insisted that was a charcoal cannister which began a lot of my confusion. So I believe everything is hooked up correctly.
The fuel pressure regulator is recommended for the weber carb to reduce the pressure to 3.5 to 4 psi. I have this along with the pressure gauge on the pressure side between the fuel pump and carb. The pressurei is only 1.5 psi. So it seems I need to either replace the fuel pump or possibly plug the fuel return outlet, which when I tested gave it the 5+ psi pressure. I have actually read on this forum that plugging that fuel return outlet is suggested when used with the Weber carb.

 

I would suggest you find the native pressure of the airtex pump. Unless you're offroading at odd angles 4.5ish psi is fine for a Weber. Using an fpr you can probably plug the return, but I wouldn't recommend it unless you have some specific need to do so. With a functional return the stock type pumps do fine for street use.

 

That is a crazy long line seems like you could swap the barb on the carb so it was on the right rather then left and cut out almost all that fuel line. Just spit balling here but maybe all that line is causing a pressure drop? I know the longer hose I put on any of my transfer pumps slow down the fluid, and decrease pressure.

 

Yeah, it is pretty long. I actually originally mounted the fuel regulator to the manifold, but I could not get that and the gauge connected in that short distance between the pump and the carb without kinking the hose. And it is possible that that length could decrease the pressure a little, but this is so drastic I don't think that is the main reason. I am about to go out and try plugging that return line and see how it runs. I am sure the pressure will go up above 5 psi and I can adjust that regulator to the right setting. I am not sure what that best setting is as I have heard anything from 3.5 psi to 5 psi for this weber. But anyway, anything is better than the 1.5 psi I currently get.

 

I think the idea is you can adjust it. so if you start getting over flow you can decrease the psi, to prevent it. Basically 5 if fine for normal use but if you are doing steep off roading, and what not, then you need a bit lower psi. Until I came across this site I never seen anybody go through the trouble of putting on a gauge, they would just put the regulator on and adjust it till it worked right. Like full psi, then just knock it down a bit each time till it was all leveled out and any poor performance due too high pressure was gone.

 

Right. I have come to the conclusion that I need to just go ahead and replace the fuel pump. Then no doubt every thing else in line will work right. I went ahead and plugged the return line and I was able to adjust the regulator up to 4 psi. However, it fluctuated considerably, probably due to the fact that I am not getting a steady flow from the fuel pump.

 

What is the eccentric like that drives the pump is it in good shape??

Some time pumps leak internal your not getting any gas in the oil are you??

Has this ever worked Correct??

This truck came in a big box all in pieces??

 

Sorry, I have no idea what the eccentric is your referring to. It is a mechanical pump. No oil/gas mixing. But I do believe there is an internal leak in the diaphram of the pump which is keeping it at a low pressure by returning too much gas to the tank. Surprisingly it was and is running pretty well with the low pressure that it is pumping out. It is because I am adding the regulator/guage that I am discovering these things. This was a salvage vehicle and I am not sure what the PO did to get it on the road. I am pretty green when it comes to auto mechanics and am making a concerted effort to become proficient at maintaining this truck. I will replace the pump in a day or two and go from there.

 

The pump has a arm on it. That arm rides on the eccentric inside the head. It is ran off the timing chain. If you take the valve cover gasket off you can see it. Smooth round off centered thing on the top timing gear. In this pic it is between the timing chain gear, and the distributor gear. Note: this is not my pic and is a picture of a 22re so it has a electric fuel pump rather then the manual, you have so its not installed in this pic.

 

Chuck,

The only thing you have to look out for with Weber's is too much pressure. If the truck runs fine at 1.5 psi, drive and be blessed.

The reason Weber recommends such low pressure is that the needle and seat inside the carb are very weak and cannot hold much over 4-5psi from overfilling the bowl. Most folks run under 4psi as a safety precaution or because they're off-roading.

If your fuel pump can supply an appropriate volume of fuel at 1.5psi and your truck is running fine, leave it be. If your truck does not run well and your fuel volume is not adequate then you can try just hooking the fuel pump to carb directly and running it. You aren't going to make your Weber explode like a JDAM by running it straight off the pump sans regulator. I've been running my truck for almost a year with no regulator on a stock mechanical pump without any problem whatsoever.

The folks using regulators either have an extreme circumstance that warrants its use (off-roading) or use them as a precaution against over-powering the Weber either through paranoia, modifications requiring an FPR or sufficient fundage to warrant an unnecessary expenditure.

You most certainly could run into problems playing around with the fuel-return line coming from the mechanical pump. I would, under no circumstance, recommend running the mechanical pump without the return line unless you were also using a regulator. However, with the return line hooked up you should be able to run the truck on just the pump, provided that the pump you have isn't pushing out much over 4.5-5psi. The return line might divert pressure over that point, but it might not. Never tried it myself.

 

http://www.carid.com/airtex/mechanic...-mpn-1330.html

3.5-4.75 PSI. My guess is that its native pressure on a 22R is closer to 3.5 because of the spacer between it and the head.

I'd run it without the regulator and just use your pressure gauge to check it. It's probably working just fine.

 

I also ran a non regulated weber in my first 22r for about 8 years, never had an issue and got 35+ MPG. It was a 2wd. My nephue also ran it that way for awhile before putting back on all the smog stuff to get it registered in California.

 

Schnayke,

Always nice to meet another sensible, non-paranoid Yota fan.

Folks vehemently recommend using regulators out of kindness and concern on their part, and it's harmless (though expensive) at worst and at best can help keep some newbs from having to tear into their carb from a mistake. Fact is, for street use, Webers can handle 5+ psi even though Weber doesn't recommend it. Being the factory mechanical pump is pretty weak on pressure and has a return line as well, the only times it would overpower a Weber are off-road at odd angles. Everybody off-roading a Weber ought to use one.

I've also run an electric, non-return 2.5psi ONAN fuel pump for 5 years on a 32/36'd 20R to absolutely no ill effect. The factory in-tank electric pump worked fine as well, until it died. I currently have an ONAN pump as a backup installed under the hood on my 82.

 

Wow! Great info from you guys!

It IS a fact that with my original hookup, I am only getting 1.5 psi to the carb. Seems pretty low, although, yes, it seemed to run fine. Upon reading so much about adding the regulator to the carb being necessary for the weber, with some pretty adamant about its necessity, I went with it and yeah, probably wasted $100 plus all the fuel line/clips I bought. I am thinking though that it is possible with such a low pressure going to the carb from the pump, it may be on it's way out and maybe I should replace it.???

 

If you want to be sure, bypass the regulator and run the carb right off the pump output with a pressure gauge between the pump and carb. If it's putting out 3.5-5 psi without the regulator then the pump is soundly not your problem. Leave the return line hooked up.

It's a moot point if the truck runs fine through it's whole RPM range at 1.5psi though. Pressure isn't the big factor unless it's too high. Flow/volume is the factor. As long as your fuel flow is fine, 1.5psi should be too. In fact, crawlers run under 2psi frequently. Of course, they aren't revving their engine high either.

You did buy the right regulator, though. Lots of guys have success with the Holley reg, but I wouldn't use one myself. The setup you have is the best one I've seen.

Carbs unlimited sells the same one LCE does. I think it might actually come in Weber branded packaging. It's a good reg, just a lot of people don't need it.

 

OK, I went ahead and hooked the return line back up and now just have the short hose connected between the carb and the fuel pump (no regulator). I was able to put the pressure gauge inline. This time during idle the gauge jumped between 1.5 psi and 2 psi. When I increased the rpm around 1800 rpm it fluctuated between 2 and 2 1/2 psi. So apparently the flow was impeded somewhat when I tested with that 5' of fuel line with the regulator hooked up, as Schnayke pointed out. I test drove it and its running very well so I will leave it as it is and use the new regulator as a paperweight. I bought a timing light recently and planned on doing that procedure for the first time, but I honestly don't know how it could sound any better than it does now. I'll check it anyway to get familiar with the procedure, but probably won't adjust it.

 

8-10 degrees BTDC if you aren't pinging is a happy place to be.