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Fuel pressure Regulator

mwoodfield

NAXJA Forum User
Location
Arkansas
This might be the wrong place to post this, but here goes.

I'm working towards a stroker swap in my '87 XJ. I have a late style intake and TB to use, but the fuel rail uses a single line instead of the two on the earlier versions. I secured a '91-'96 fuel rail, but it has no regulator and the reg retaining bracket is gone, and I can't find one.

I recently purchased a '00 GC w/4.0 and noticed the regulator is built into the fuel filter located near the tank. Replacements are $50.

So the big question is: could I use a WJ filter/regulator on my RENIX 4.5 stroker with a single line to the rail instead of trying to find all the parts for the older style? Pressure looks to be a constant 49psi. There is no vac control of the reg. I will be using 4 hole injectors from a 4.6 Ford Crown Vic police with the RENIX control setup. TB will be adapted to the RENIX TPS.

Any help would be appreciated. I tried searching, but got no relevant results.

Thanks
 
The RENIX and Mopar rails are completely different. Renix fuel pressure regulator (FPR) bolts on to the rail with a bracket, Mopar uses a clip. The late XJ style is single line with the FPR part of the pump in(at) the tank. My thought was to use a WJ filter/regulator that mounts in the line from the pump to the rail. No tank mods required, or mods to the rail. Just connect the Renix return line to the WJ FPR near the original position of the XJ filter.

The big question is will the constant fuel pressure be a problem since the WJ does not have a vacuum control for the FPR.
 
i am very aware that the rails are different and never mentioned fuel rails

96 cherokees have a one year only in-tank pressure regulator that is more or less in a 95 down style fuel sender. you could plug the return lin on your sender up and use that reg.
 
I was not aware the '96 was different. That might be a viable option.

Thanks!

Any thoughts on the on fixed pressure? Do you know what the pressure on the '96 spec'd at?
 
Well...a little quick research. Rock Auto does not show the in tank one for the '96.

Found this using Google at cherokeeforum:

"Old 08-01-2012, 11:37 AM #23
rrich
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Location: Landers, CA
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A few of the 96's had the regulator mounted on top of the fuel pump. If it's not on the rail, then it's back there as part of the top of the pump. Most 96's were on the fuel rail. It was very limited production - some were export models.

The pressure on the 96's with the tank regulator was higher than the rail type - to stop the proverbial "heat soak." No vacuum was used. It was the forerunner of the later type.

Unfortunately replacements for those are hard to find - 97's were different yet. The 96 was unique to only some 96's.

Check with your dealer - if they search they can find it. Parts houses won't show it.
Last edited by rrich; 08-01-2012 at 11:40 AM."

Looks like it's back to the WJ idea. Really don't want something parts are not readily available for.
 
I run the 91-95 fuel rail on my renix jeep.

There are a series of different bolt in regulators you can get at different pressures.

Find a 91-95 rail. Bolt it in. Pick your pressure. Have fun.

PR210 39 psi (stock)
PR211 50 psi
PR209 55 psi
PR321 58 psi
 
Thanks for the info on the FPRs. I have the rail, just no clip to hold in the FPR. Guess I need to go back to the salvage yard and look some more.
 
I have the WJ style FPR/FILTER in my 88 Renix Stroker.Easy to do_One side goes up to fuel rail single line.which is better no hot fuel back to tank.The other side has 2 lines.Simply use the return line back to tank into the stock return line on sender.I believe I had to switch it from 5/16 to 3/8 or vise versa with a brass adapter fiting.Just use Fuel Injection hose and Fuel Injection clamps.I monted mine where stock filter is.Done
 
I run the 91-95 fuel rail on my renix jeep.

There are a series of different bolt in regulators you can get at different pressures.

Find a 91-95 rail. Bolt it in. Pick your pressure. Have fun.

PR210 39 psi (stock)
PR211 50 psi
PR209 55 psi
PR321 58 psi
I have a 96 DD and the regulator is the in tank one year only.It can be replaced with one mentioned above.it uses the stock rail type,It pops out of that housing.My stroker in the 96 uses the pr211 unit.
 
It's better to keep the hot fuel in the fuel rail? Does better mean something different there?
Manufacturers went with single line due to warm/hot fuel from engine going back to tank created excessive evaporative pressure build up in tank.The fuel in the return less style is constantly getting cooler fuel via... fresh supply.I believe a cooler fuel helps with power same as cooler intake air helps.
 
Another route to consider might be a ZJ tank with the ZJ pump/regulator assembly. While '96 assemblies are scarce as hens' teeth the ZJs are more common. I have not done the swap myself, but evidence around here suggests it is viable and comes with the added benefit of a bit more tank capacity.

Just some food for thought.
 
Manufacturers went with single line due to warm/hot fuel from engine going back to tank created excessive evaporative pressure build up in tank.The fuel in the return less style is constantly getting cooler fuel via... fresh supply.I believe a cooler fuel helps with power same as cooler intake air helps.

manufacturers did many things to favor emissions at the cost of performance and economy.

returnless gives the fuel a lot of time to heat up in the rail and is a net loss.
 
I have the WJ style FPR/FILTER in my 88 Renix Stroker.Easy to do_One side goes up to fuel rail single line.which is better no hot fuel back to tank.The other side has 2 lines.Simply use the return line back to tank into the stock return line on sender.I believe I had to switch it from 5/16 to 3/8 or vise versa with a brass adapter fiting.Just use Fuel Injection hose and Fuel Injection clamps.I monted mine where stock filter is.Done

I was wondering if this had been done. Seems like a pretty simple solution.

Thanks for your reply.
 
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