vr ss 5 speed poor performance

[luko015]

Hi guys, I have been searching the forums for hours and haven't found any new info on things that I haven't already tried. I swear the car had a fair bit more poke than it currently does, especially down low (under 3000rpm). I have replaced plugs, leads, dizzy cap, fuel filter, pump tested as A.O.K(done in last couple of months, has had a new radiator and clutch fan setup fitted, new water pump, K&N hi -flow air filter fitted. Injectors cleaned, TB cleaned, injector rail cleaned(done in the last 2 weeks), inlet maniold gaskets checked-fine (replaced 18 months ago), timing set, all ignition system checked-fine, doesn't appear to be the O2 sensor. Has had a lukey sports exhaust fitted (2.5inch from memory) 18 months ago, pacemaker extractors 4 months ago. No errors in diagnostic mode, I have been checking this on and off for the last 6 months. Due for a dyno tune as soon as the mechanic fixes his dyno. Is there anything I may have overlooked? I have had 3 different mechanics check the car, all say it is ok, they all tell me the engine is in good nick(has 150,000 k's on it). Any help appreciated.

[Whales]

Check coil packs?

[Vee-ard]

What do you mean by poor performance? does it splutter or is slow? what sort of 0-100 times are we talking?

[luko015]

Really sluggish, more a lack of acceleration, doesn't splutter. At a guess would say 8-9 sec for a 0-100km/h run, could even be worse to be honest. Used to be able to punch it off the the line and straight away it could loose traction (not dumping the clutch either, this was before injector clean, extractors etc. ), struggles to do so when I crack 2nd at full stick.

[VrWagz1]

TBH the only way ur gonna diagnose this for sure is on a dyno, or you would need to be very proficient with efi live. If you think its down, have a dyno tuner run ur car and compare it with other 304's. The only thing i can think of off hand is one of ur cam lobes may have been wiped.

[Kioes]

Did you happen to have a new throttle cable fitted prior to this happening? A few weeks after I replaced mine I notices a slugging acceleration turns out the wire cable had stretched so I just had to tighten her up for better response again.

[luko015]

kioes, nah haven't replaced throttle cable, although have taken the slack out of it. VrWagz1, if it was a cam lobe (which I had thought of but noone has checked) wouldn't I hear it clunking around or feel it?

[Brendo169]

if it was a cam lobe you would hear it! thats what happened to my 5L and it made a terrible racket!! you would also have tiny shavings of metal in your oil....like a pearl paint almost

[luko015]

brendo, any other suggestions? I know people like vrwagz and yourself know more than I do, so im not to discount anyting i'm suggested, just thought i'd hear a broken lobe. Unless its just worn???

[dirt drifter]

its a long shot but maybe check the timing to make sure the dizzy hasnt shifted and backed it off a few degrees

[Brendo169]

brendo, any other suggestions? I know people like vrwagz and yourself know more than I do, so im not to discount anyting i'm suggested, just thought i'd hear a broken lobe. Unless its just worn???

yeah mate im not sure what else it could be. maybe the next step is to get a full dyno tune and go from there? just out of curiosity what sort of mileage are you getting?

you said that youve checked all the ignition system. For what they are worth i would be whacking in a new coil just to make sure its not that. Also if youve got any mates with 5L's just 'borrow' their ignition module for a little while and see if you get an improvement

[luko015]

not exactly sure on litres/per 100k's, but definetly uses more juice than it used to. Unfortunately none of my mates hav 5L's! Waiting on mechanic to fix his dyno! 3 mechanics here have them, 2 are broken and the other guy I wouldn't even trust him to look at my car. I will triple check the timing, just in case.

[VrWagz1]

I was only thinking that a lobe was rounded off, not so much broken. Which would mean no clunking from bits. But as above one would think you would have some evidence in the oil if that was the case. Never seen it but my mech (long time family friend and family business) has seen it a few times. He recons its usually one of the rear lobes that wears.
But could be sensor related thats just out of calibration like the map or oxy sensor. Could be fuel pressure reg, but i would think you would have just general all round performance issues if this was busted.

[luko015]

Hey boys, vrwagz, seems like you may be right, the cam seems to have gotten a little hungry!! New cam on the way from crow cams, will let you guys know if the issue is resolved! Thanks for the input, I really appreciate all of your help.