Limp Mode, CEL, Some Power Back

[KentSzabo]

Today I left my house in my 2002 Golf GLS TDI drove the 1/3 mile in 2nd to the highway, ambient temperature 70 degerees. Got to the highway and there was a car 1/4 mile from my road, so I hit it (WOT) in 1st, then 2nd, shifted to 3rd, and died till I backed off throttle. Drove 35 miles with only slightly less power noticed going up hills. Stopped after 35 miles for 10 minutes. Started it up again for the trip home. I heard the turbo whine as usual, got back onto the highway and no power at all, less than the 80 Rabbit diesel I used to have. Went like this barely maintaing 55 MPH, till I started to coast down a long hill 10 miles later, and then I hit the throttle and got back up to 75 MPH, but as I was going down the long hill before I hit the throttle the Check Engine Light came on. Drove for another 3 miles and had no trouble maintaining 75 - 80 MPH. Idecided I better see if anything was noticeably wrong under the hood, so I stopped in a small town and looked but saw no trouble. When I started up again no CEL and no power, after a mile or so I was downhill again, and the power restored itself. I drove between 65 to 75 MPH the rest of the way home, but not quite the same power and accelleration as yesterday. CEL is of course still on. It seems there is no power after starting until I get the CEL to come on by going downhill.
The car has had an Epsilonian device since 200, on the odometer, the CCV elephant hose bypass since 500, and an Upsolute chip since 4700. PiperCross panel since 9500. This all started at 11500 on the odometer.
I don't have a VAG com, so I am probably going to the dealer Monday with it.
Does anyone have any ideas as to what may be wrong? I recall seeing posts about the limp mode, but I don't recall any about the popwer coming nearly all the way back.

[ September 14, 2002, 16:27: Message edited by: KentSzabo ]

 

[VelvetFoot]

I would say, try it without the Epsilon device, and if you bring it back to the dealer, restore motor to stock as much as possible.

 

[KentSzabo]

I will disconnect the vaccuum hose and hook it back up to the EGR, but I really hate to unsolder the wires at the MAF connector.
Some additional notes:
It's been 2 hours since I shut it down, so I went to start it again, and no CEL for 1 minute idle, romped on accellerator three time 900 RPM to 3000 RPM, at first no sound of turbo, then CEL and turbo sound when bringing it from 900 to 3000 RPM. It seems like only the turbo is working when the CEL is on.

 

[VelvetFoot]

Here's a scenario: There is something wrong with the MAF circuit, whether it is Epsilon-induced or not, and when the ECM figures it's a dead MAF it sets a CEL and goes into constant-MAF-value mode.

 

[KentSzabo]

Thanks for the advice. I decided after another 100 miles on it with the CEL I will get a non dealer VAG-COM opinion. If it is the MAF or turbo I would like to be fore armed when approaching the dealer. Neither the Epsilonion device nor the CCV mod would have any bearing on the problem then.