g60 holding back at full throttle

[vagingit.co.uk 0]

Strange issue with the C, if you accelerate with 75% throtttle, it goes very well, and will rev all the way up to the redline, but if you floor it, it pulls but then seems to hold back around 4k.

The car should be healthy, having a full service a month ago (new leads to go on this week), the charger was rebuilt last year, the silencer box has been replaced with a BBM RSR outlet, and its running a SLS Tuning 68mm pulley and chip

 

any ideas? blue temp endr replaced lst year with genuien vag if it makes a difference. could it be elated to my stickingidl speed when cold?

[unitfight 0]

sounds exactly like my g60! mine is especially bad in 3rd and 4th gear like what you said at 4k revs when you floor it!

 

i thought it may be the throttle switches, i replaced mine with a 2nd hand set but no joy.

 

my fuel pressure is good

 

boost holds at 10psi

 

i dont think the charger belt is slipping

 

so im holding it down to spark or fueling. maybe dizzy or coil??

 

or fueling side could be injectors, CO pot, lambda, or map sensor which i heard is capped to 1bar limit on some models??

 

also....mine runs REALLY well when i first boot it from cold. i guess because cold start is still engaged.

 

IF ANYONE COULD SHED LIGHT ON THIS YOU WOULD MAKE ME AND THIS CHAP VERY HAPPY INDEED :clap:

[Rob_B 0]

The standard map sensor runs to 1 bar, but you are only making 10psi so it's irelevent.

Is it making the full throttle switches? Does it only do it when it's full throttle? If not it could be the lambda probe. Try taping up the switches and driving it.

[Album56 0]

What fuel are you using? If the knock sensor detects pinking when the timing advances with revs it will start retarding the timing cutting power, if you dont already use it try a tank of good 99RON fuel to see if that fixes it. Although the G60 will run on cheaper unleaded they do like higher octane fuels especially in the summer. :D

[vagingit.co.uk 0]

Its always run on Tescos 99 RON super, or Shell v-power

How do I test the throttle switches? If the lambda was buggering around, wouldnt that cause issues elsewhere? It runs sweet as a nut in all other ways.

 

Is the co pot the white topped box on the boost pipe from inlet manifold to the intercooler? Is it difficult to change, or is it just a case of removal then putting a different one in its place?

 

I know G60Greeny had a similar problem a while ago, but was unable to find any posts where he had solved it

[Rob_B 0]

the CO pot is the one in the boost pipe with a 3 wire plug. you should get a certain resistance across the 2 outside pins when the engine is off. cant remember off the top of my head but i can find out.

you can test the operation of the throttle switches using a multimeter. basically the car will run on lambda when its not on full throttle, and when on wide open throttle it will run on your map. (someone correct me if im wrong please)

so if the car runs poor when not on wide open throttle, then it could be the lambda probe. if you tape the wide open throttle switches closed, then you will eliminate the lambda probe from the equation.

if it runs poor with the switches taped up, it could be a dodgy knock sensor

[unitfight 0]

tested my throttle switches, they are ok! lamda came up good on the lambda probe tester.

 

will try the resistance on the co pot, but they are near impossible to buy new arent they??

 

someone say knock sensor?? mines not pinking at all, timing is spot on to, could it still be that??

[Rob_B 0]

could be a faulty knock sensor. doesn't need to pink.

[unitfight 0]

anyone know what the resistance of the knock sensor should be? gonna go round my whole engine bay with a multimeter today.....fun. test every sensor and carry out continuity checks on as many wires as i can!

as my engine is in a caddy van, although a superb conversion, tampering with frail old wires may have cause a break somewhere. im thinking maybe on the WOT switch loom.

anyway, off to work!

[dannyboy 0]

sounds more like the fuel map on the chip isnt well suited to your engine.sounds like either dumping too much fuel in or timing on the dizzy is out.

mine was the same and different chip+adjusting dizzy timing made it run better.i still get that little delay of two seconds in the map and then you get that extra little pull as the mapping kicks in bit like turbo lag.

Co pot doesnt really effect anything other than control fueling slighty on idle. CO pot should be around 500 ohms but every engine slighty runs different.

 

One big thing to check is the vacumn hose to the ecu,wont run properly if its old or wrong length.this is the biggest controller of fuel for the engine.

On WOT the lamba sensor and CO pot are not used so its not really down to them

 

to test the WOT switch,push it in while engine is running,the engine tone will change and will hunt.

[unitfight 0]

didnt know that the co pot doesnt controll fueling on WOT!? handy to know, nice one. yeah i do get the standard digi-lag, but i get the flat spots intimitantley also when booting it.

i replaced the ecu vaccum hose already. 1m EXACTLY! already tested the throttle switches and they are ok. set up the timing spot on the other day.

 

hmmmm.....im still running standard ecu chip :) i keep meaning to get in contact with sns! that could probably be my problem!!

 

im sticking it on the emmisions tester tommorrow to see if its running rich or lean on throttle. will see what happens! cheers for the help chaps

[vagingit.co.uk 0]

well, Im just in the process of changing ignition components, new leads are goin on in 10 minutes, coil and co pot being changed

 

looks like a meter will be out though testing other parts already talked about

 

Out of interest, how do you make sure the throttle cable is properly adjusted?

[dannyboy 0]

to adjust the cable(what i do anyway) get someone in the car to push the accelarator down full,then on the throttle body pull the clip off the external cable cover.

then move the outer cover in til its tight and the throttle is wide open.replace the clip in the recess on the outer cover and test.

 

unitfight-Running smaller pulley on standard chip isnt great as the maps will be all wrong and fuelling will not be right.i did it for a while and it was very flat on the 3500-6200 range.new chip sorted it out(well the 3500 to 5800 range anyway,still get massive dropoff in power after)

[Yandards 0]

The standard map sensor runs to 1 bar, but you are only making 10psi so it's irelevent.

Is it making the full throttle switches? Does it only do it when it's full throttle? If not it could be the lambda probe. Try taping up the switches and driving it.

 

Pressure switch runs to 2 bar not 1 bar.

 

It's the map tables within the ECU that's wrong.

 

When the full throttle switch on a G60 is open (ie part throttle or idle) the ECU runs on 'closed loop' this means that the lambda is the sensor in charge and adjusts the fuelling to maintain an ideal AFR (air fuel ratio) this is why at part throttle the car feels quicker than WOT (wide open throttle) as the lambda is sorting out the fuelling in the ECU.

 

When you hit the full throttle switch the car switches over to open loop and relies on input from the MAP (manifold air pressure) sensor within the ECU and the map settings within the ECU to sort the fuelling, these are corrected for coolant temp, air temp and CO levels but the amount of variation is small compared to the MAP and ECU map setting.

 

What you really need is a custom chip doing for your setup, an off the shelf item will work ok but for best performance you really need a bespoke chip for your car. The reason is that unlike the VR both the G60 and the valvers had looser build tolerances at the factory so one engine can make 150 bhp whilst another manages 170 bhp, so to get the most from yours you need to get it adjusted for your car.

 

I can highly recommend DG Autotech for a custom G60 having just had one, my own G60 is massively improved and now pulls like a train, should set you back no more than £200 in total.

 

Finally the reason why stock G60s dont make any power after 5800 rpm is that the ISV opens from around 5300 rpm up to 5800 rpm dumping boost back to return. It does this to reduce the shock loading on the engine on the approach to ECUs rev limit of 6200 rpm, this protects the charger above all else in the engine so it is a good thing.

[dannyboy 0]

yans,does the ISV have a mechanical boost limiter(boost overcoming the plunger) as well as beening actuated by the ecu? I had a spare ISV and had a play with the adjusting screw while ago and dropoff in power came at 6100 instead of usual 5300-5800

or have i just played around with the idle return tension?

[unitfight 0]

some amazingly usefull stuff there yandard! will check that company out about the mapping.

 

i was looking at jabbasport custom code remap but they are more pennies :(

 

was looking at SNS chips, as they configure the chip to suit your setup. obviousley wouldnt be 100 percent as each engine has different characteristics, but ive heard they are very good for the money!! £100 + p&p

[Yandards 0]

Adjusting the ISV screw will move the boost return point around the rev range, it will also nerf your idle.

 

I really can't recommend the custom chip enough, an off the shelf SNS item will help but it won't be as good or as safe as a custom item.

 

DG bolt another knock sensor onto the existing one and Dave also uses a set of head phones as part of the tunning process to get the maximum from the engine.

 

Well worth doing and definitely a day trip for you in Hampshire.

[dannyboy 0]

yeah i did think that and idle was bit bouncey

 

Wheres DG yans? bit of a trek for me but for a decent map sounds interesting

[Yandards 0]

yeah i did think that and idle was bit bouncey

 

Wheres DG yans? bit of a trek for me but for a decent map sounds interesting

 

Kidderminster so the middle of England really.

 

Website is http://www.dgautotech.com/dgauto/

[mimjed 0]

also....mine runs REALLY well when i first boot it from cold.

 

oh dear

[unitfight 0]

also....mine runs REALLY well when i first boot it from cold.

 

oh dear

 

 

:lol: worded wrong... when i 'accelerate' from cold should i say. so much more responsive and pokey!

[mimjed 0]

still shouldnt be shoeing it when its cold dude, thats how to kill a charger in no time. nice and steady up to 3k.

 

dont get me wrong i send mine to the redline in second about once every six months when the temp hits 50 to clear some crap out.

 

76 is your best friend with a g.

[unitfight 0]

i dont take it beyond 3.5k on cold. i mean its responsive and neck jerking upto that even without flooring it. dont do it too often as its still running cold start at that stage and makes me sobb watching the fuel guage creep.

 

still never red-lined my 'G'

 

dont worry nimjed, my 'G' is in safe hands....take care of it more than my preggers wife :)

[mimjed 0]

lol, icve never hit the redline on mine, its been set higher so i dont get the back pressure. stick to the redline on the clocks.

 

yeah i know what you mean, just have to drive like a granny til its warm. always seem to get someone giving it the big dog when its stone cold too :(

[unitfight 0]

lol, icve never hit the redline on mine, its been set higher so i dont get the back pressure. stick to the redline on the clocks.

 

yeah i know what you mean, just have to drive like a granny til its warm. always seem to get someone giving it the big dog when its stone cold too :(

 

 

lol! i dont get that problem cause my 'G' is in a caddy van!! no one wants to go the rails against a van with a huge postman pat softtoy in the passenger seat :lol:

 

love my sleeper :) suprised an impreza the other day