wtf, so im driving. sometimes it will stutter like its not getting fuel for a second. does it bad when i floor it sometimes. random rpms. ill floor it, it will cut out till i take my foot off the gas. otherwise it will sit there for a second then go again. i changed the plugs wires and fuel filter. fuel pump? ecu? what could it be?

 

have you checked the TPS voltages? fuel pump voltages would help too and checking for loose grounds around the engine bay and ECU. Do you have a DMM that you could back probe into these components and monitor while you drive?

 

nah i dont. i was thinking tps... but havent varified it. i was also thinking it could b the fuel pump going out. havent found much info on symptoms to back up my theory

 

Dirty injectors or maybe clogged cat.

 

you can get one for cheap at any parts store. just ask for a digital multi-meter.

as far as fuel pump issues go, check the fuel pressure with the fuel pump connector switched engaged and the key in the on position. what are you getting for pressure?

 

i was also thinking injectors. im running rb header straight piped to my mufflers so no cats. and when it hesitates the rpms dont dive bomb. just laggs for a second or 2 while it missfires

 

jayce i got a dmm

 

****, its getting worse. more frequent and it will kill over sometimes. i changed ecu. made no difference. now im gonna focus on fuel pump and relay. possibly tps

 

fuel pump or injectors. prolly wouldnt hurt to fork out the ~80 bucks witchhunter wants to get those injectors serviced.

 

How many volts are you running? I would definately make sure your fuel pump is getting enough power. I had the same problem, loose ground.

 

I agree, sounds like a shitty injector or two.

 

I was having the same issue awhile back got worse and worse, turned out it was the pulsation damper, and fuel pressure regulater both went bad on mine. you can do the output check for the pump. at the end there was no wot for me half way down and it would spit and sputter.

 

do s5s have pulsation dampners? if so where the hell is it? i have an s5 motor in mine and running the s4 harness. has been fine for over a year.

 

I have all S4, so IDK. but on the S4 the pd is on the primary fuel rail, I replaced mine with a banjo bolt. seems to be holding up. I've got other issues now always somthing with these bitches. keep you on your toes.

 

answer to your question the s5 primary fuel rail houses the pd internal.....while the s4 houses it external which can be replaced or banjo bolted shut like jinxed4dub was saying. I have a s4 primary rail sitting around if you want. Remove the pd and banjo bolt case solved.......however im not sure thats the fix to your problem. thejallenator had a good point to get those injectors cleaned at witchhunter. Its cheap and probably needs to be done anyways if yours has never had attention in the past 20 years lol. Main point is the s5 primary rails pd do fail but not often since they are internal. You will have to replace. Check your fuel pump voltage asap

 

i feel like such a moron... i fixed it of course but i found that the green plug on the back of the thermo housing was barley in there. i pushed it all the way in and walah! no misses and no cut outs. this is of course after i tried replacing the fuel pump, lead coil, spark plugs, wires. fuel relay, ecu, fuse box near battery. all that and nothing. then i see the little plug clinging on for dear life by a thread.... how annoying....

 

At least we fixed it bro. Look at it this way, You got a New Fuel Pump, Fuel Pump Relay, New ECU, New Coil and New Fuse box Cause of me Haha

 

ya thanx again. i floored it all the way to work this morning cuz i missed the redline buzzer haha. oh and i had the ecu already. got it from that chap who gave me the bunk engine

 

crazy, ive had that one unpluged before and the car stilld rove pretty well, just not when it was cold. never woulda thought the thermo senser would cause that extreme of problems

 

ya i think its becuz it was slightly plugged in to wear it was making connectivity, just not full connectivity. the metal clip on it is gone.

 

Well I was right on the loose part haha.

 

i have the same problem with my car except worse. what i have done and have to do still is i've got a new throttle positioning sensor in it and i need a air intake sensor. thats suppose to fix it.

 

the pressure sensor that bolts up by the passenger strut tower? has a lil adjustment screw on it. has a vacuum hose that goes to the intake mani.. i might have one

 

I think he's talking about a AFM. not the pressure sensor.

 

oh well i got one of those too