GolfGTIforum.co.uk
Model specific boards => Golf mk4 => Topic started by: gti_shaun on 21 March 2010, 14:57
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hi all, i recently had a MAF fault on my AGU, as the car was pulling back and revs dropping right down on idle,(ALSO HAD MAF SIGNAL LOW FAULT CODE) after logging the maf on VAG-COM the reading was doubling on idle so causing incorrect fuel etc, anyway i bought a bosch maf as i thought they make them for vw anyway so should be ok, fitted it, it sorted idle issue and the pulling back and runs sweet, but when i have started the open up the throttle and give it some on the motorway, it is not going to 21psi peak boost like it used to, it only goes to 18psi and drops and holds about 14psi , its had made the car feel quite a bit slower and took the seat pinning feeling away, and is no where near as giddy spinning up the wheels when i purposely floor the throttle when i have been testing it.
sorry about the essay
i could do with a very kind AGU owner willing for me to borrow their MAF for 5mins to see if it is that or i have got a boost leak or something instead, but it would seem to have only gone like this since new bosch maf was fitted.
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hi all, i recently had a MAF fault on my AGU, as the car was pulling back and revs dropping right down on idle,(ALSO HAD MAF SIGNAL LOW FAULT CODE) after logging the maf on VAG-COM the reading was doubling on idle so causing incorrect fuel etc, anyway i bought a bosch maf as i thought they make them for vw anyway so should be ok, fitted it, it sorted idle issue and the pulling back and runs sweet, but when i have started the open up the throttle and give it some on the motorway, it is not going to 21psi peak boost like it used to, it only goes to 18psi and drops and holds about 14psi , its had made the car feel quite a bit slower and took the seat pinning feeling away, and is no where near as giddy spinning up the wheels when i purposely floor the throttle when i have been testing it.
sorry about the essay
i could do with a very kind AGU owner willing for me to borrow their MAF for 5mins to see if it is that or i have got a boost leak or something instead, but it would seem to have only gone like this since new bosch maf was fitted.
I am experiencing the same problem with my AGU plus the car is still holding back ever since I swapped out the maf 2 weeks ago. Checked on vagcom, but no faults came up. The next thing I am going to try is to swap out the n75 valve as suggested by others and see this makes any difference.
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i have one you can borrow for 5 mins. If you're worried about leaks i can stick your car on the smoke tester for some beer tokens :afro:
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ive got exactly the same problem, ive had new turbo, new maf, new n75 valve and still im only boosting at 15-18psi think ive got a boost leak somewhere :angry:
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i spoke to nick at R-tech and if i dont get anywhere he said he would stick it on the leak tester and have a look over it. thanks anyway topher, TBO i dont think i have a boost leak, its to much of a coincidence that it happen stright after the new maf,
if you get anywhere master_oogwai please let me know and i will do same, what MAF did you fit gen or bosch?
Ive just had a good visual inspection of all pipes etc, with no obvious leaks, ive also used a mitivac to test the actuator for leaks(OK)
are you down leicestershire tho topher, i could do with someone a little more local, i just want to hopefully prove the new maf is at fault get my pennies back and go VW for one :angry:
i hate it when threads like this get left with no answer(FIX) so i will keep you all posted.
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Also mines the same, since i added a forge TIP the car went well at first then a week later the power kind of dropped off and its not like it used to be.When i fitted the TIP i had to trim a small piece off the hose to make it fit at the turbo,this surely cant make a difference.Or is it a change in the weather who no`s..
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Will do mate. I got my new Bosch one from my local vw branch.
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i spoke to nick at R-tech and if i dont get anywhere he said he would stick it on the leak tester and have a look over it. thanks anyway topher, TBO i dont think i have a boost leak, its to much of a coincidence that it happen stright after the new maf,
if you get anywhere master_oogwai please let me know and i will do same, what MAF did you fit gen or bosch?
Ive just had a good visual inspection of all pipes etc, with no obvious leaks, ive also used a mitivac to test the actuator for leaks(OK)
are you down leicestershire tho topher, i could do with someone a little more local, i just want to hopefully prove the new maf is at fault get my pennies back and go VW for one :angry:
i hate it when threads like this get left with no answer(FIX) so i will keep you all posted.
Nick will use the same smoke tester.......
Topher = R - tech :laugh:
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ive got exactly the same problem, ive had new turbo, new maf, new n75 valve and still im only boosting at 15-18psi think ive got a boost leak somewhere :angry:
yours is an AUM isn't it Ry? maybe worth binning the pcv pipework mine was split on one of those pipes :sad:
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i spoke to nick at R-tech and if i dont get anywhere he said he would stick it on the leak tester and have a look over it. thanks anyway topher, TBO i dont think i have a boost leak, its to much of a coincidence that it happen stright after the new maf,
if you get anywhere master_oogwai please let me know and i will do same, what MAF did you fit gen or bosch?
Ive just had a good visual inspection of all pipes etc, with no obvious leaks, ive also used a mitivac to test the actuator for leaks(OK)
are you down leicestershire tho topher, i could do with someone a little more local, i just want to hopefully prove the new maf is at fault get my pennies back and go VW for one :angry:
i hate it when threads like this get left with no answer(FIX) so i will keep you all posted.
Nick will use the same smoke tester.......
Topher = R - tech :laugh:
dammit you got there before me :grin:
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ive got exactly the same problem, ive had new turbo, new maf, new n75 valve and still im only boosting at 15-18psi think ive got a boost leak somewhere :angry:
yours is an AUM isn't it Ry? maybe worth binning the pcv pipework mine was split on one of those pipes :sad:
No matt its a AGU :wink:
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ive got exactly the same problem, ive had new turbo, new maf, new n75 valve and still im only boosting at 15-18psi think ive got a boost leak somewhere :angry:
yours is an AUM isn't it Ry? maybe worth binning the pcv pipework mine was split on one of those pipes :sad:
No matt its a AGU :wink:
Bin it anyway :wink:
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I know is not a correct or good thing to be doing but if you clamp off the pipe to the actuator it runs full boost with no n75 control, i did this before to make sure my turbo was ok, it went stright upto 21psi maybe a little more so im thinking its ok, has anyone else tried this if so what boost was made(i have ko3s)
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no 0ne done this then to make sure the turbo can produce good boost, just wanted to know it it should have gone higher
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didnt even know you could do it tbh will try it out :wink:
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wont it throw up error codes if u clamp it?
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ive got exactly the same problem, ive had new turbo, new maf, new n75 valve and still im only boosting at 15-18psi think ive got a boost leak somewhere :angry:
yours is an AUM isn't it Ry? maybe worth binning the pcv pipework mine was split on one of those pipes :sad:
No matt its a AGU :wink:
Bin it anyway :wink:
my sucki meechi(however you spell it) catch can has come today so will be replacing it
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i occasionally clamp the n75 on a car to check it can make full boost without ECU control - it's a good test to make sure your turbo can hit full boost but that's all - and you shouldn't leave it like that for more than a 100 yard blast for testing or you risk damaging the turbo and engine. It won't really give you much of an idea as to what is causing the boosting issue (other than eliminating mechanical failure)
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right tried the n75 valve clamp and it boosted to 22psi and felt as it did before when i was running 237bhp if not faster, so does this mean i can rule out a boost leak? or does it mean i need the actuator adjusted?
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Seems like it mate. Where did you go the other day anyway i turned around to fetch the smoke tester and you'd disappeared :grin:
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i did a log on my maf before and it peaked at 175 g/s this it right for 225bhp right?
have you tried a n75 valve darkgti?
Think thats where i may go next, just hate shelling out money and not knowing if its gonna fix it.
so just to confirm you fault is the same DARKGTI when it used to come on boost it just flew stright up to 21psi stayed there for a bit the dropped to 18ish, then next gear same again etc etc
NOW the boost does not seem to fly up as quick and gets to 18 psi and stays there, but im pretty sure the needle on the guage flutuated like it wast to boost higher but cant, then drops to 14psi(1bar) as the revs go higher.
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oh forgot to ask topher, is 21-22psi right for the ko3s with pipe clamped? what does yours blow? i thought it should of been higher but i guess they are not the biggest turbo in the world.lol
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Latest update.
Due to R-Tech being 117 miles away from me and I really wanted the car looking at asap, I made a journey to see the lads at AmD, as they are half the journey away from me. I asked them to fit a new standard n75 valve for me and put the car on their rolling road. The results were interesting, though the power and torque curve were not very smooth. This time, the torque tailed off at 5000rpm whereas at R-Tech, it tailed off at 5500rpm. On the road, the car is still a little jerky.
However, the dyno results:
1st run - 239.2bhp/259.8lbft
2nd run - 231.4bhp/251.5lbft
At R-Tech, the car made 209bhp/240lbft
Fairplay, you would need to take in account of the dyno, weather and so on, but now I dont know what to think?? +30 bhp from changing the n75, even though the car feels no different on the road??
Think I need to run the car on someone elses RR for a third opinion.
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wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*
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wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*
What would you advise then topher? shall I bring the car back down to you guys for further investigation?
Really hoping for the issue to be resolved, but I am at a loss now.
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RR lottery :wink:
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RR lottery :wink:
I agree, but the differences are huge.
One is saying the car has an issue and the other is saying the car is fine :undecided:
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so does your car still not feel right not boosting fully then?
^^^^^^^^^Anyone tell me if my air flow reading is ok and if the boost is high enough with the actuator clamped off^^^^^^^^^^^^
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wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*
What would you advise then topher? shall I bring the car back down to you guys for further investigation?
Really hoping for the issue to be resolved, but I am at a loss now.
Does it not feel right to drive anymore? I think we're at the limits of internet assistance now dude. I'm not sure if i'll be at r-tech much the next few days so probably best to call up and speak to Nick.
gti shaun i think you need to start a new thread because i've no idea what you're asking or what your issues are :grin:
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wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*
What would you advise then topher? shall I bring the car back down to you guys for further investigation?
Really hoping for the issue to be resolved, but I am at a loss now.
Does it not feel right to drive anymore? I think we're at the limits of internet assistance now dude. I'm not sure if i'll be at r-tech much the next few days so probably best to call up and speak to Nick.
Fair enough mate. Think I will give Nick a buzz. I would like to see if there are changes on your RR now that both maf/n75 have been changed.
The issue is like gti_shauns new thread. Before maf swap, you hit the gas and the car goes, like that night on the test drive with you after the map. After the swap, the car seems to lag so you dont get that instant hit. At first, I put it down to the warmer weather, but its the same whether it is cold or not.
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now your saying yours is the same i maybe back on to the new maf being crap, its funny as we both swapped mafs and got same stuff going on,can you not get your old maf back and stick that on? i tried to get mine but they already shipped it they said :sad:
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now your saying yours is the same i maybe back on to the new maf being crap, its funny as we both swapped mafs and got same stuff going on,can you not get your old maf back and stick that on? i tried to get mine but they already shipped it they said :sad:
I doubt it, as it was two weeks ago when I swapped it over. I am tempted to try another maf.