GolfGTIforum.co.uk
Model specific boards => Golf mk4 => Topic started by: barry-gti on 15 June 2010, 09:20
-
So... i've still got boost problems!
The VVT has been changed and has sorted the timing problem, a resistor is in place where the secondary air intake was, and 3-4 different N75's have been tried!
The fault is most definatly electrical as whenever the Maximum charge pressure surpasses fault is cleared it boosts fine through 1st - 2nd gear and once it senses a bit too much boost it all goes t!ts up!
Basically now, it boosts weak to 15psi and as soon as it touches it, it rapidly drops to about 5-8psi. and stayes there the whole rev range... if you take your foot off and plant it back down it does the same thing again and again... untill you clear the fault... then it's 20odd psi for a bit, and then the same symptoms...
it sounds like a boost leak when it goes into this limp mode... but it's definatly not
We're looking to change the MAP sensor when i can find one attached to a standard side mount
But, does anyone else have any ideas what it could be?
Cheers
-
if it's not a sensor (try maf as well as map) only thing i can think of is the actuator or it's rod got bent/damaged during the engine swap.. although i'm sure i had a quick check for that last time you were over this way :undecided:
what are they getting from logs of the map and maf sensors?
-
We're not getting nothing back, just maximum charge pressure surpassed...
But it couldn't be the actuator if it's running fine for a little bit everytime the fault is cleared could it?
-
You not got full VAGCOM Barry? Get some MAF logs done!
-
Log MAF, MAP (block 110?? 115?) and load - Block 25
-
Ok. I'll ring the garage and see what they can do... They've got a full VAG-COM...
Cheers!
-
They going to charge for that? I have full vagcom if you can get te car this way...
-
Nah they won't charge... I do really owe them a drink though! Been down there a few times and they haven't charged me n I've had no cash to give 'em lol...
-
Logs were done apparently, not showing no faults I don't think... When we get a chance me n bav are gonna use his map sensor n maf and see what happens!
-
Logs were done apparently, not showing no faults I don't think... When we get a chance me n bav are gonna use his map sensor n maf and see what happens!
Can you get hold of the log files at all??
-
I doubt it, it wasn't on VAGCOM it was on a smaller device... I'll try get some more at some point, what are they supposed to be/look like?
-
Excel documents ;)
-
Right...
Me n BaV have changed over his MAF, MAP and N75 to mine and it was still running sloppy. But, I've found a pipe that was supposed to be on top of the wastegate / actuator! so we've put that on and it's a lot better! it doesn't sound like a boost leak no more but it's still overboosting a little...
So i'm assuming now it's got to be actuator??
Cheers
-
the actuator vac line wasn't attached? :shocked:
does the actuator rod move smoothly by hand?
-
We'll have to check that ina minute because it's cooking under there!
Are you ok to talk us through the MAF / MAP logs on VAG-COM if we ring you (if you don't mind, PM me your number)
Cheers mate...
-
Mainly @ Toph this one...
Do you advise me Tweaking the N75 screw at all? after discovering the 7psi overboost there must be away of tweeking that instead of the actuator or even the map?
Cheers
-
no leave it well alone mate .. if swapping n75 with bav made no difference it isn't worth the risk of knackering the n75 and wouldn't help cure a suspected jammed wastegate issue anyway
did you manage to get that log of 118 yet?
-
We aint had a chance yet mate. To be honest I might just leave it till I'm in the area hopefully in the near future n get you to take a look at it