Author Topic: uber slow alh mk4 tdi?  (Read 5001 times)

August 27, 2009, 04:39:06 am

sawedoffgolf

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uber slow alh mk4 tdi?
« on: August 27, 2009, 04:39:06 am »
so my girlfriend just bought a 01 jetta tdi, and after reading/hearing alot of stories they sound to be fun/peppy/torquey.. however my 1.6td seems to be way faster and peppier than the mk4. Its uber slow, im not sure what could be up with it or if its normal, the p/o had just replaced: maf, injectors, glowplugs, and the timing belt within 1000kms ago, is there a chance that the IP timing could just be off? i dont have the dial indicator to check timing, is there another way? i know most of you are going to say "get a chip, get bigger nozzles" if it aint broke dont fix it basically, but once the injectors need to be replaced it would be a good time to upgrade them anyways.

Reply #1August 27, 2009, 06:28:39 am

gigaz2

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Re: uber slow alh mk4 tdi?
« Reply #1 on: August 27, 2009, 06:28:39 am »
forget about opening the hood for now, get a vag com cable and diagnose it.
the small vacuum pipes that run to/from the turbo selenoid are known to crack and leak, the selenoid is also known to go south.
the intake can be clogged with grime from the egr, it mixes with oil vapour and produces a black goo that completely closes the intake.

those would be my first bets
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Reply #2August 27, 2009, 08:01:50 am

lord_verminaard

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Re: uber slow alh mk4 tdi?
« Reply #2 on: August 27, 2009, 08:01:50 am »
Can you hear the turbo at all?  Even at idle, in neutral, you should be able to blip the throttle and hear the turbo spool a bit.  If not, I'm guessing the turbo vanes are stuck.

Brendan
81 Scirocco 'S -->Soon to be m-TDI
93 Corrado SLC VR6
'86 Golf N/A Diesel  -->Wife's car
1990 Audi CQ
05 New Beetle PD TDI


"I am a man, I can change... if I have to.... I guess....."

-Red Green

Reply #3August 27, 2009, 02:46:57 pm

sawedoffgolf

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Re: uber slow alh mk4 tdi?
« Reply #3 on: August 27, 2009, 02:46:57 pm »
Can you hear the turbo at all?  Even at idle, in neutral, you should be able to blip the throttle and hear the turbo spool a bit.  If not, I'm guessing the turbo vanes are stuck.

Brendan

can definitly hear the turbo, but when driving i cant really "feel" it spooling up, my rabbit throws you into the seat when it spools up but the tdi doesnt really feel like its spooling or it has low boost, what is the factory boost rating? ive taken the inlet to the egr off and theres a little carbon/soot build up in the egr valve im gonna get a new intake manifold gasket and possibly the egr delete stuff and do that sometime soon. also there is no CEL on so i dont think there is a vacuum leak or bad solenoid..

Reply #4August 28, 2009, 02:36:04 pm

lord_verminaard

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Re: uber slow alh mk4 tdi?
« Reply #4 on: August 28, 2009, 02:36:04 pm »
Factory boost is around 14 psi I think.

Brendan
81 Scirocco 'S -->Soon to be m-TDI
93 Corrado SLC VR6
'86 Golf N/A Diesel  -->Wife's car
1990 Audi CQ
05 New Beetle PD TDI


"I am a man, I can change... if I have to.... I guess....."

-Red Green

Reply #5August 28, 2009, 10:32:55 pm

sawedoffgolf

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Re: uber slow alh mk4 tdi?
« Reply #5 on: August 28, 2009, 10:32:55 pm »
ok ill hook up a spare gauge and see what im getting. also, would air in the fuel lines make a difference? im usually getting some small bubbles.