Cleaned MAF, and car is slow again :(

[McDub]

Finnally got around to doing 0-100 sprint times.

pre-chip: 8.7 sec
post-chip: 7.3 sec
post-maf replacement: 8.0 sec

So it's sitting somewhere in the middle.

ok since then i've had it looked at reasonably thoroughly, replaced diverter valve, replaced the N75 (J type), new sparkies, cleaned throttle body, new coolant temp sensor cos old one was apparently faulty, and the time is still:

post-service: 8.0 sec

so it didn't improve it the slightest bit!
this is really sh**ting me big time. what the hell is going on???

If it's of any use, the unitronic program is supposed to run the car at a nominal 16psi.
Reading off my crappy NewSouth guage, in 1st it gets to 10psi, in 2nd it gets to 15psi, and in 5th it actually gets up to 18psi and sometimes a little more!

Just so much about my car is shi77ing me right now. For one the installation of the boost guage seems to have stuffed up the Dim circuit on my dash, the new single mass flywheel n clutch seems to chatter when it starts to engage under 2000rpm which is moderately annoying... We took the hard dogbone bushes out and returned to stock cos it was terrible IMO.
the boost guage needle vibrates at max boost which is an easy fix but i havn't got round to it yet...
my gearbox is di*ky and rough between gears and sometimes even at the lights it physically won't go into first...
i just want someone to steal the car so i can start over!


I'm gonna get it inspected on a dyno to see if that will help shine some light on the matter...

[fuzion]

ok since then i've had it looked at reasonably thoroughly, replaced diverter valve, replaced the N75 (J type), new sparkies, cleaned throttle body, new coolant temp sensor cos old one was apparently faulty, and the time is still:

post-service: 8.0 sec

so it didn't improve it the slightest bit!
this is really sh**ting me big time. what the hell is going on???

If it's of any use, the unitronic program is supposed to run the car at a nominal 16psi.
Reading off my crappy NewSouth guage, in 1st it gets to 10psi, in 2nd it gets to 15psi, and in 5th it actually gets up to 18psi and sometimes a little more!

Just so much about my car is shi77ing me right now. For one the installation of the boost guage seems to have stuffed up the Dim circuit on my dash, the new single mass flywheel n clutch seems to chatter when it starts to engage under 2000rpm which is moderately annoying... We took the hard donbone bushes out and returned to stock cos it was terrible IMO.
the boost guage needle vibrates at max boost which is an easy fix but i havn't got round to it yet...
my gearbox is di*ky and rough between gears and sometimes even at the lights if physically won't go into first...
i just want someone to steal the car so i can start over!


I'm gonna get it inspected on a dyno to see if that will help shine some light on the matter...

anyone reading this?

did you reset your throttle body firstly through vagcom/vchecker?

have you checked all your hoses? the vacuum hose going to the fpr tends to be very brittle and leaks/breaks.

did you install the boost gauge correctly with no boost leaks?

are you sure you put the right spark plugs in?

oh and regardless what ive read or heard, maf needs to be replaced usually not cleaned. and do you have a oil based filter?

[Golf Loon]

Also worth checking the O2 sensor as a stuffed MAF often finishes them off, which will make the car run rough and slow.

Sounds like you have been taking it to the wrong people mate, get someone competent who understands VWs to check it over.

[McDub]

fuzion, i assume it's been reset etc... though i thought that was just for DBW.
hoses havn't been inspected properly, however no obvious leaks can be heard. and yes no leaks with boost guage... well apart from when a hose came off while driving resulting in the guage reading atmospheric...
sparkies were put in after problems happened so their not the problem, but yes they would be the correct ones
Golf Loon, yes the O2 sensor has been considered. it is going to be looked at again though. unfortunately when i got the car dynoed today, we couldn't get a readout from the OBDII port to compare with the figures from the probe.

so yeah i got it dynoed today at MRC in Castle Hill because it was near work and someone recommended them
http://www.mrcdyno.com.au/

assuming generous 30% losses for the stock 110kw motor, you would get 77kw atw
with the unitronic program that claims 145kw in the states, you would get 102kw
And as i expected, i got somewhere in the middle:

All figures are plotted with RPM on the X-axis...

KW and Nm (i think the torque is an estimate at the flywheel, no idea why...)


Boost and AFR


KW and AFR


And here, the lead to the N75J was unplugged because he wanted to see how it would react under just the normal spring force of the actuator... cos i think he thought it was loosing too much boost, but may not of realised at the time that it's likely just because it's a small turbo...


as you can see, it seems to be running very rich at high rpm's.
the old spark plugs where quite black so that agrees with that i suppose.
and the power curve looks very rough too.
this was the 3rd run. the first run the power curve looked a lot smoother and it got 94kw. 2nd run it got 91.

so from here, the O2 sensor is going to be looked at again, these images are gonna be sent to Unitronic in Canada to see if they can shine any light on the matter, if not much happens of that mark from mrc suggested an exhaust back pressure test incase the cat is stuffed... and yeah that's about it. but he reckoned it's more likely a problem with the program (as i have wondered all along...), but time will tell... hopefully

[kaneda]

Sure its not a boost leak ?
Kinda strange how the boost stays so level across the range as you would expect it to go up n tapper off .
Running rich mean there is too much fuel but maybe its not enough air ?
Did you do a leak test ,only takes a few minutes and can save a lot of hasel
.

[McDub]

Sure its not a boost leak ?
Kinda strange how the boost stays so level across the range as you would expect it to go up n tapper off .
Running rich mean there is too much fuel but maybe its not enough air ?
Did you do a leak test ,only takes a few minutes and can save a lot of hasel
.

no i'm not sure it's not a boost leak. but the boost only stays level on that last graph because the solenoid valve is NOT being operated as the lead to it is disconnected. it was just for a test.
look at the boost in the second graph. hits 17.5 psi and tapers off. that's how it normally is acting.

[Jmac]

Have the system smoke tested, will find any leak in under 10 mins without fail, no need to remove any hoses or anything. Takes away the "is it a boost leak" question we see all too often, if it is the smoke will pour out of it no question. Have someone read the 02 sensor, watch how it reacts to a vac line off and watch how it reacts to some added chems like carby cleaner fired in a line somewhere, the 02 sensor should be very quick to respond to that. If not its suss. An 02 sensor dying will be lazy, tell the computer its very lean so the dumb computer then fires bucket loads of fuel in thus the rich mixture. Take away the guess work with the leaks though, smoke test it, you can even get smoke with Uv these days
Jmac

[McDub]

i'll put off a smoke test for now (anyone know someone who can do that in syd?)
and as to the O2 sensor, i'm told by a few people that at WOT that the car should be running on a predetermined map so the reading won't affect anything... this true?
anyway unitronic think that there might be leaks with the intake, or the new MAF i got could be a dud... luckily still got receipt.
so i'll have a quick look at the TIP, then if nothing shows up we'll try test a new MAF. I mean these seem like obvious things that you would have deduced from what caused the problem in the first place... yet i've been trying everything else to fix it so far... so fingers crossed this time.

[Jmac]

i'll put off a smoke test for now (anyone know someone who can do that in syd?)
and as to the O2 sensor, i'm told by a few people that at WOT that the car should be running on a predetermined map so the reading won't affect anything... this true?
anyway unitronic think that there might be leaks with the intake, or the new MAF i got could be a dud... luckily still got receipt.
so i'll have a quick look at the TIP, then if nothing shows up we'll try test a new MAF. I mean these seem like obvious things that you would have deduced from what caused the problem in the first place... yet i've been trying everything else to fix it so far... so fingers crossed this time.

Back to leaks suggested mate, a good diagnostics tech will have a smoke machine, will find ANY leak in your intake system mate, guessing without it and will take less than an hour to do, if there is no smoke then there is no leak simple no magic thats it, itll find a slightly loose hose clamp believe me mate
Jmac

[Golf Loon]

Yeah McDub, take it to someone competant with actual diagnostic skills, who can fix the small problem, not take a punt with lots of your cash, changing random and expensive parts.