Correct.

Cut it off...

S4 is easy. You just unscrew the FPR, take the rail to an engineering supply shop and buy a threaded adaptor to take a rubber hose. Or if you're into expensive bling you buy AN fittings to do the same thing. With an S5 rail you'd have to cut the FPR off and weld on a threaded steel boss to take the same fitting.

That's why you say "click link in sig."

Have you tested the fuel pump voltage yet?

 

ahh you'd slap me if you could, i havent checked the fuel pump voltage yet, i probably will tommorow, i was out racing the car tonight and it seems as if the hesitation has slowly gotten better....

although i have high RPM hesitation, i'm suspecting ignition break-up....

regardless, do you have a picture of an S5 fuel rail by any chance?, or would i basically hack off past the stock FPR and weither how short or long the rail was, just weld on an AN fitting for a fuel line?...

 

I thought AN fittings were aluminium. You'd have to weld a steel threaded boss to take an AN adaptor.

Do you need the expense of AN fittings and SS hoses?

 

Well, I had a hesitation problem. Turns out that the coolant line from the back of the water pump was leaking onto my LIM. Which destroyed my LIM gasket. When I took my LIM off, the gasket was very jacked up. So, maybe make sure all your intake gaskets are alright.

 

Make sure your ignition coils are grounded properly. Did you move a coil to make room for your FMIC? Is your fuel-filter good? AFM good? Are your injectors grounded properly, tight seal at the grommets? Good voltage to their plugs?

If you have a buddy with a wideband O2 sensor, you should try to borrow it--that way you can see if you're running rich/lean when these hesitations occur. Just another way to trouble-shoot.

Also, are you running STOCK NGK plug-wires?

 

ofcourse not, but if you could give me options for the S5 fuel rail i'll definitly do what you suggest....

 

i put grounding straps from each coil to the neg. on the battery, yes i moved one of the coils but it's grounded with a strap so it should be alright?...

fuel filter is good, AFM i have no idea how to check that, injectors are grounded properly, and, how do i check the voltage to their plugs?...

 

THERE ARE NO INJECTOR GROUNDS! How many times does this need to be repeated? Other than adding resistors for low-imp injectors, there should never be any mods performed on the injector wiring.

While there's no reason the wires have to be the stock NGK ones, old ones should be replaced. I've experienced a bad intermittent misfire that turned out to be a bad spark plug wire. I bought one cheap generic plug wire (the longest available) with the intention of replacing the original ones one at a time to see if one was faulty. Luckily for me the first one replaced was bad and the problem was cured the problem completely. I later replaced all of them with a set of Magnecors.

What rails you use doesn't effect what hose and fittings you use. If you use the S5 rail you still have to weld on a threaded fitting so you can screw in an adaptor of some kind. If it were me I'd be using brass fittings and rubber fuel injection hose. IMO AN fittings and SS hoses are just expensive bling on a street car.

"Grounding" the coils is completely pointless. The coils are already grounded to the chassis through the base of the ignitor body. All you need to do is make sure the mounting points are clean and secure. Sand off the paint under them.

See the FSM page F2-80.

I really hope you haven't done anything to the injector wiring...

Disconnect the injector clips, turn the ignition on and check that there's 12V on one pin in each plug. Really though this shouldn't be necessary because if the engine runs right through the rev range then all four injectors must have power. Far more important is to check that all four clips are completely clean inside and securely attached.

 

Ok all not to jack the thread...but on an s5 GTU with a stock setup where would you go to check why the car is hesitating... Here is what i've done so far...

Cleaned and sanded all grounds...
Checked MAF to make sure there are no leaks AFTER it...
Plug wires are new and plugs are good...

 

whoops, my bad, i meant that i grounded the injector harness, not the injectors themselves....

ok so weither rail i use, you say to use brass fittings?, what type of metal are used for each rail, being S4 and S5?, brass can be.... welded.... to it?...

and you say, there's no direct difference in size and/or flow between each rail?...

sorry if i'm repeating myself....

 

The S4 rail is aluminum, the S5 rail is steel. A brass fitting will screw straight into the S4 rail once the FPR is unscrewed. I highly doubt you can weld brass to steel, which is why you weld a threaded steel boss onto the rail and screw a brass fitting into that.

I'm not sure about internal diameter, but in terms of hose fittings, injector fitment and mounting points they're completely interchangeable. The ID of the rails isn't that critical anyway, as it's driven by the physical size of the injectors and is considerably bigger than the ID of the hoses feeding them.

 

i really hate to pester you, but you say i'm to screw a brass fitting onto the S4 fuel rail, what type of fitting do i use?...

do you have a somewhat step-by-step guide as to what i'm supposed to do and how i'm to make this work?...

i'm kind of in the dark here....

 

I had the same hesitation, not in first gear (because it revved through the range too quickly) but in second gear. I found that the pulsation damper screw was backed out (my PD is now a banjo bolt.) After repairing that, the car runs like a top. I would almost certainly agree with the above theories of it being fuel-related.

 

A brass fitting with a thread on one side and a hose barb on the other. Take the rail and some 5/16" fuel hose to an engineering supply store and tell them you wan't to connect the hose to the rail. They'll give you the correct fitting.

It'll look something like this (but these guys don'thave the right one):

http://www.fittingsandadapters.com/maleconnector1.html

Getting back to the actual problem, have you checked the fuel pump voltage yet?!

 

you'd hit me if you were around, but no i havent....

it's been -10 or worse the past bit, i've neglected the car, infact, i havent even driven it....

 

I'm having an exact hestiation with my 90 TII that's just been rebuilt.

 

when you figure out whats wrong with yours, help a fellow rotary head out!...

 

Same here

 

is it a 6 port?? the actuators are supose to be activated by exhaust pressure, taking out the kats reduces back pressure. so you get a hesitation while the pressure builds to open the 5th and 6th ports... check them.

 

It's a TURBO...

Not that a problem with the 6PI system could cause a hesitation anyway.

 

so i installed my MSD6AL, gears 3rd 4th and 5th have lost most of the hesitation when i get on the gas, but 1st and 2nd are still horrible....

 

Did you check on the alternator as a source of interference with the wiring to the ecu?

 

how do i check that exactly?...

just losen and take the belt off the alternator, or, unplug it?...

 

you replaced the spark plugs yet?..and have you tried a Different AFM?,changing Fuel filter?

 

plugs, yes, fuel filter, yes....

AFM?, no....

would it even make a difference?...

i get no hesitation in 4th and 5th now....