1990 FC3S TII

Well, the Saga continues......
The Hitman's 13BT 3 bar, 4x720 map is perfect (should start the car just fine) however we are still having fuel delivery problems. The timing is correct and the engine is firing just fine. We thought after repeated attemps to start the car that it would have been flooded but when we pulled the plugs, they we NOT covered in gas. The injectors are brand new ND's. from Rx7.com. I am running the fuel rails in paralel...does that make a differance? What should my fuel press. be? Could my ECU be busted? If so how come all the other sensors read/register just fine I am soo frustrated right now it just isn't funny. WHAT COULD BE WRONG?

HWO

make sure your fuel injectors aren't disabled on your fuel set up page, make sure the terminals in the plugs are in properly, i had this problem myself, my primary injector in the front rotor wasn't connected properly.

tims

What do you mean by fuel rails are run in paralel? what type of fuel pressure regulator are you using? the best way is to have one supply and then link the fuel rails together(series). some regulators have the end of the rail closed and others have it return to the regulator. I would make sure you have fuel at the rail and a pressure above 40psi at the rail. fuel should feed one rail then continue to the second rail this ensures consistant flow. also check that there is spark at all plugs.

1990 FC3S TII

I am using a new SX regulator. I am running the rails like this



.............__PRIMARY RAIL___
REG___I....EMTYSPACE.........I___________RETURN
.............I__SECONDARY____I

In MHO this should be a better way to run the fuel because both rails get the same pressure at the same time! IS THIS OK???

tims

no this is not OK. all fluids will travel the path of least resistance. so most of the fuel will flow through one of the rails and not the other. which SX regulator do you have? is it the small one without the guage port or is it the fat square one with the guage port?. both are not plumbed the same. check the install instructions and at least feed one rail then the other and then back to the regulator. line from pump to fuel rail then to secondary rail the back to regulator and return line from regulator to tank for small regulator. large regulator, line from pump to regulator then to rail then to secondary rail, secondary rail is then capped(does nor return to regulator), regulator return line back to tank. as you can see different regulators use different plumbing routes. I have used both of these regulators with good success.

1990 FC3S TII

Yes, I am using the one with the gauge port! I have no instructions though. So I should run them in sequence?

1990 FC3S TII

Thanks Tims!

I get it now.....(I had just woken up when I red you message)
I'll be starting her up later today!!!...I'll keep you posted!

0piston

iTrader: (9)

Hi TIMS, I am in the process (right now) of replumbing my fuel system. I have the SX regulator with the guage port.

this was the route I was going to do--am doing, is it ok? =>
fuel line from tank >K&N Fuel Filter>primary fuel rail>secondary Fuel rail>sx regulator>back to tank.

thanks!

Scott 89t2

here is a pic of adrians fuel setup (180k)
http://www.1300cc.com/rx7pics/adrian/eng8.jpg

running the rails like this would not cause it to not start. if you have pressure in one rail you will have the same pressure in the other.

Scott 89t2

and I'm asumming you made this wrong as i don't think chris is that supid, but the reg goes on the return line... (the one without the fuel filter)

if chris set it up like in your drawing your problem is found.

HWO

see my thread called "it says i need a subject line" it was supposed to be a reply in this thread

1990 FC3S TII

I had the diagram all lined up in the composition section but it pulled everthyin over to the left and up 1 line screwing up the diagram.


I'll be switching to a serires set-up tmrw. HOPEFULLY IT STARTS up!

tims

that regulator should have the fuel line from the pump to one of the ports on the side of the regulator then from the other side of the regulator to the fuel rails. go from one rail to the other(on my car it is the top rail and then the bottom)and the second rail should be plugged at the end and not return to the regulator. then the line on the bottom of the regulator goes back to the gas tank.
pump------regulator------rail1-------rail2
I
I
I
tank

hope this is a good enough illustration.
when we first started work on one of our race cars the regulator was plumbed as you have it. it would start and run but this was not the reccommended plumbing by the manufacturer. if it is still not running check the engine options page and verify that the computer is seeing the correct rpm. this was a problem with another of our cars. hope this helps.

tims

sorry I could not get the diagram right on this text box. tank should go to bottom of regulator sorry for the confusion.

0piston

iTrader: (9)

Cut from HWO post relating to this:

"it tells me i need to have a subject line
i cant seem to understand your picture but it looks a bit odd to me, it should be like this if you are running them in parrellel

High pressure line from the pump
primary rail secondary rail
regulator
return line"

This seems right to me... TIMS what differences/advantages did you see by plumbing it via SX's recommended manufacturers specs?

Scott 89t2

yes this is how it is. adrians diagram above was wrong. tims I can't see how your way would work? you wouldn't have any pressure in the rails?? I havn't seen any instrutions for it though.

1990 FC3S TII

All I know is that all this is making me mental!

1990 FC3S TII

FAINALLY! For the first time since November 27th by car runs! I switched the fuel rails to seires and it runs just fine! HOLY CRAP DID IT SMOKE! (new engine) Thanks sooo much for all the help! Scott, I am never going to listen to you again! hehe...

RUNING THE FUEL RAILS IN PARALELL DOES NOT WORK!!!!!

Thanks again guys. you ruel!
And last but not least, THANKS ALOT TO CHRIS my mechanic for coming over to deal with all this crap!
:1party:

Scott 89t2

yeah it does. you also swaped the injector connecters at the same time to the right ones.... now you will never know untill I do mine in parallel.

1990 FC3S TII

actually, we only swapped one and decided they were actually fine! IT DOESN NOT WORK YOUR WAY!! DEAL WITH IT!

Scott 89t2

he had both primarys cut off when I left, which is what your car is running off, we will see what happens when you give it some gas the and the 2ndarys don't come on...

tims

please do yourself a favor and check with the manufacturer on the fuel plumbing they recommend for there product. it is a simple phone call and they are very nice and it will only take a minute. this is what I did when I sort of inherited a bunch of parts with no instructions. I have a turbo II race car with 15 events run with this setup. I have never had a fuel supply problem at any time. when I first started working on the car it was plumbed as the picture in this thread it would run but very poorly. I called the manufacturer the tech guys explained how they recomended the plumbing and my fuel supply issue was solved. 1990 FC3S TII good to see the car is running now comes the tuning. have fun and watch that boost guage.

0piston

iTrader: (9)

Hi TIMS, What type of fuel delivery problems were you experiancing exactly with that setup? THX

tims

it would run but not very smoothly. idle would hunt around and when run over 2500 rpm(point at which secondary injectors come on on this car) but it was inconsistant. it was very frustrating and basicly I had to go through all systems and verify everything. the only thing we found was that the regulator was not plumbed right. this was already on the car when the owner bought it, so we had assumed it was right. a five minute call discovered the fuel system was not right. some of the aftermarket suppliers parts are not supported very well, lack of instructions is only one of the problems. I am glad the car is running, because I have struggled with new motors and fuel injection that wont work.

The_HITman

Looking at the diagrams it is easy to see what was wrong.
0piston had it right. The reg goes after the fuel rails, not before.
Running them in series or parallel makes no different, but the placement of the reg will effect things dramatically.

If you were playing around with primary and secondary injector wiring, be sure you have the INJ1 and INJ2 going to the two bottom primary injectors, INJ3 and INJ4 going to the two top secondary injectors. If you are unsure, disconnect the top two injectors and see if the car still starts and idles. If not then you have them mixed up. The car will run either way, but will flatspot off idle if they are back to front.