When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Is there any reason that we can not modify our engine fuel lines to the simple 993 fuel line route. The 993 has only 2 basic lines, fuel liine in to right injector rail, fuel line across to left injector rail. Left rail has fuel pressure regulator. Short of replacing the 964 fuel line system with the complete 993 system could/can the 964 fuel rail use the simple cross over method and the regulator moved to the end of the left rail. I have attached a picture of the 993 system and the 964 system. So what I am talking about is bring the fuel in on rail 2at the front (top right pic). Then taking the fuel out by the number 3, going across to rail 1 near number 8 and then placing the fuel pressure regulator on the number 1 rail by number 1. Maybe use the 993 pressure regulator or modify the 964 to work. Has anyone done this? or see an issue with why this can't be done on the 964 to reduce the complesxity of our fule line route and numbers? Thanks
Dammit! I just sent my lines around the world to get them redone- haha. I may just sell them and go this route if it turns out to be a simple as it seems.
especially because I can’t find a 964 regulator....
I’ve been running 993 fuel lines in my 964 for several years now. From what I remember, it’s pretty straightforward. You also need the input line #6 in the parts diagram at the top of this post. Only downside is that the lines were expensive even though I bought them used. And, as long as you’re in there, 993 injectors are much better pieces too.
The only issue I see with modifying the 964 rails to the 993 is what regulator would you use and how would it be mounted? The 993 uses a fairly common Bosch drop in design fuel regulator but has the mounting point a s part of the end of the fuel second rail. You would need to come up with a regulator that would work otherwise I don't see why not. The 993 had a lot of things simplified compared to the 964. I am assuming it was some of Toyota's influence in how to build these cars. If I were spending the money to replace all my 964 lines with new factory parts i would consider swapping to the 993 bits for about the same money. Although rebuilding them with better fittings and lines can be done for less. IIRC the 964 lines cost around $750 for all of them vs $744 for the 993 parts minus the regulator. Although just buy Bosch for less money than the Porsche part.
good news is that Sleepers Speed shop is going to make 964 regulators for us that need them. Its still in the R&D phase. (I dont know what the price will be.)
Could we do something like this without buying 993 parts. (see drawing ) Replace all fuel lines and make a 993 look alike - use metric/AN6 or AN8 fitting and stainless hose to make. Mount the 964 Fuel P Regulator in the left front and cap off one of the old in line openings using only one in side.. This would duplicate the 993 fuel line routes and simplify the system to a degree. I don't see and issue with using only one side of our FPR as the fuel would still be regulated with the rail before being routed to return line
Could we do something like this without buying 993 parts. (see drawing ) Replace all fuel lines and make a 993 look alike - use metric/AN6 or AN8 fitting and stainless hose to make. Mount the 964 Fuel P Regulator in the left front and cap off one of the old in line openings using only one in side.. This would duplicate the 993 fuel line routes and simplify the system to a degree. I don't see and issue with using only one side of our FPR as the fuel would still be regulated with the rail before being routed to return line
I wonder what the differences in flow rate are between the 964 rails and 993. Seems to be a different shape, diameter and more bends.
Is it necessary to run the 964 fuel pressure regulator? As I said, I’ve got the 993 rails in my 964 along with a 993 regulator and it seems to work fine.
Not necessary if you have one. Your set up is fine. I don’t have any 993 parts ( rails or regulator), but I like the simple line flow of the 993 set up so am tying to figure out how to do using my 964 parts. Keeping what I have to buy to a minimum.
Not necessary if you have one. Your set up is fine. I don’t have any 993 parts ( rails or regulator), but I like the simple line flow of the 993 set up so am tying to figure out how to do using my 964 parts. Keeping what I have to buy to a minimum.
993 fuel pressure regulators are $50 on Amazon. At that price I wouldn’t risk cobbling something together.
Is it necessary to run the 964 fuel pressure regulator? As I said, I’ve got the 993 rails in my 964 along with a 993 regulator and it seems to work fine.
I contacted URO several months ago regarding availability of a 964 pressure regulator. They indicated it was being worked on but did not have an expected release date yet. Might be worth a call if you can't locate one.
993 fuel pressure regulators are $50 on Amazon. At that price I wouldn’t risk cobbling something together.
You will want to verify the pressure. They make many versions all look similar and can range from 2 to 5 bar of pressure. The 993 uses 3.8 Bar IIRC. Either setup can flow more fuel by changing fuel pressure. Your pump and lines from the tank to the engine can be the limiting factor.
11-21-2019, 02:28 PM
993 Engine Fuel lines/regulator vs 964
