Author Topic: MK4 Jetta TDI ALH slight loss of power?  (Read 330 times)

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MK4 Jetta TDI ALH slight loss of power?
« on: Sep 13, 19, 08:45 »
Looking for some help from the brain-trust in regards to my 2001 Jetta ALH.

In the last few weeks, I've deleted the EGR valve and replaced my intake manifold with a decarbon'd one. With those two changes, the car's responsiveness and torque dramatically improved. The car was now quite fun to drive! I do a lot of freeway commuting which should help with keeping the carbon down. I regularly give the car a good run up the tachometer every few days and today was no different.

The engine was well warmed up and I was going onto the on-ramp to the freeway. Put the car into 3rd gear and floored it. Got the revs up to about 4300 and got a bit of black smoke out of the back which I attributed to some more carbon leaving the intake tracts. As I continued my drive, I noticed that I was lacking the "oomph" or responsiveness when going on-throttle that I had just recently acquired.
Any ideas as to what may have changed or happened? Car still sounds fine and drives OK, just doesn't have the same torque or response. Thanks!
1996 Audi UrS6 - The Ongoing Project (Samco Boost Hoses, VVME 4300K 35W HIDs, TFSI Coil Conversion, Apikol Diff. Mount, Apikol/Poly Rear Subframe + Rear End Bushings, HPR Motor and Trans mounts, Apikol Snub Mount, Bilstein Sports + H&R 29800s, Avid.1 AV-20 18x8.5 wheels, Conti DWS06 tires)
2017 VW Golf Sportwagen 1.8T - Family Wagen
1986 Audi Coupe GT - Tornado Red (SOLD)


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Re: MK4 Jetta TDI ALH slight loss of power?
« Reply #1 on: Sep 13, 19, 18:02 »
Sounds like a boost leak, creeping N75, or vane issue. What does VCDS say?
'81 Rabbit S 16VG60   |  '15 Touareg TDI R-Line   |   '96 YZF750R


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Re: MK4 Jetta TDI ALH slight loss of power?
« Reply #2 on: Sep 14, 19, 06:41 »
After you sort that out, i have a tuning box that i just removed from my sister in laws 2001 ALH, 5 spd (she's selling the car) and is looking to sell the chip for 50$ if your interested.
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