What did you do to your MKIV today?

gmenounos said:

Checked the QA<->ECU wires yesterday and all tested good. Also swapped ECUs and it still idles badly and throws a QA code. Today I'm going to try swapping in the QA from a spare pump and see if that fixes it.

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Well the new QA didn't help so I went back and retested all the wires from the ECU to the QA and they again all tested good. I noticed that VCDS could not communicate with the ECU when the engine was running, only when it was stopped and the ignition key was in the run position. Researched that and found that someone reported the same issue quite a few years back and it turned out to be a blown fuse. Checked all the fuses. Then tested all the power and ground wires to the ECU. Then checked the Relay 109 wiring. Discovered that the wire that actuates Relay 109 was broken somewhere between the ECU (pin 18) and the relay. Followed the wire and found the issue:

https://photos.app.goo.gl/YqTWPS3aASRw7Dr16

There was no wire in that wire; it had corroded away to nothing. Now normally that wire would have been buried inside a harness but this car is a TDI conversion and Relay 109 is inside the engine compartment rather than on the relay panel. The PO, who performed the conversion, had re-routed that wire outside of the harness so that it could go to the relay box in the engine compartment. I'm not quite sure why the wire broke but maybe the insulation was cracked and it just got rained on for 10 years - the break was just in front of the wiper linkage, which is exposed to the elements, though the break was underneath a layer of electrical tape. I cut out the bad section of wire and spliced the ends together with a waterproof butt connector.

You may be wondering why the car even runs with Relay 109 not functional. Because of the way the PO wired my car during its TDI conversion, some of the components that should get powered from Relay 109, actually get power from some other circuit whenever the ignition key is in the run position. Not ideal, but it works.

I no longer get the "QA Upper Limit Reached" code when I turn the key to the Run position but by the time I figured all this out it was too late at night to run the car. Hopefully it'll run OK tomorrow and I can get the IQ set correctly. I also need to check and maybe adjust the injection timing as I didn't do that after replacing the timing belt a few months ago.

I made my trunk not open anymore by putting my backpack in there and closing it. I guess now I'll have to go spelunking through the back seat, open it and hopefully just have to replace the stupid little plastic piece that supposedly breaks frequently.

Will it open if you turn the key all the way?
Mine currently is in the same boat, broken plastic- however I can open it with the key- the last bit is just a bit stubborn

I've tried, but nope.

Had the new timing belt and auxiliary items installed. This one was a little over my comfort zone so I paid an expert to do the job.

Got to work on installing a PD lift pump on my ALH Golf. Broke the wiper arm puller trying to get the wiper arms off so that I could run power to the pump. Thought I would be clever and see if the mechanical pump on the ALH could draw fuel through the unpowered pump and the Golf started and idled fine so off I went, about two miles down the hill to where the engine quit, and I determined that the mechanical pump could not draw fuel through the unpowered lift pump. I walked home and rigged up a ground wire and means of getting +12v to the lift pump from the accessory socket in the console. Sure beats pushing it home!

Intermittent turbo code and limp mode, bought a bed extender off eBay, $50 free shipping. $60 at harbor freight. Will use it on the F250 as well. Light lumber, metal roof, Craigslist diesel runs

gmenounos said:

I no longer get the "QA Upper Limit Reached" code when I turn the key to the Run position but by the time I figured all this out it was too late at night to run the car. Hopefully it'll run OK tomorrow and I can get the IQ set correctly.

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Got it all back together, adjusted the IQ and it runs good again.

Tightened up the hand brake. Replaced the small radiator fan. For the past several years, the steering wheel would pulse ever second or so when the AC was running. The new fan has finally made that go away.

Found a double-handful of soil which had formed against the snowscreen. Removed the snowscreen and tossed the debris in the yard.

I tried to figure out what's wrong with the Monsoon radio in my blue Golf, not my daily driver but the weekend car. It powers on, the radio frequency is displayed, but the volume and frequency change dials don't do anything and neither do the up/down buttons. Fuses 37 and 42 are okay. I don't have the radio removal tool kit but Amazon will deliver a kit Monday or Tuesday. It is not in SAFE mode, even though the battery was out of the car for about a month this past winter. Anything I can do when I get the radio out?

In prepping for my road trip to Iowa next month I finally replaced the partially functional led taillights with some spec d taillights with incandescent bulbs. Finally no more flashing glow plug light, and I can use cruise for the first time in the 35,000+km I’ve put on since I bought it.

Had some slight rain and found a leak by driver side footwell coming from above the dead pedal. Having done this before, I went ahead and re-sealed the electrical cover under cowl. I also cleaned out a bucket of leaves and dirt from beneath the cowl and from behind the lower fenders.

Cleenlivin said:

Had some slight rain and found a leak by driver side footwell coming from above the dead pedal. Having done this before, I went ahead and re-sealed the electrical cover under cowl. I also cleaned out a bucket of leaves and dirt from beneath the cowl and from behind the lower fenders.

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I noticed my driver’s side floormatt was wet after washing my wagon the other day. Could you elaborate more on the leak you have?

TornadoRed said:

I tried to figure out what's wrong with the Monsoon radio in my blue Golf, not my daily driver but the weekend car. It powers on, the radio frequency is displayed, but the volume and frequency change dials don't do anything and neither do the up/down buttons. Fuses 37 and 42 are okay. I don't have the radio removal tool kit but Amazon will deliver a kit Monday or Tuesday. It is not in SAFE mode, even though the battery was out of the car for about a month this past winter. Anything I can do when I get the radio out?

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There is a fuse on the back of mine.
Not sure but I thought it was for power to the amplified antenna.

Leak Under Cowl...

If your car has a sunroof it could be clogged drains, if not (at least on my 04) the leak could be from around a plastic cover beneath the drivers side of the plastic cowl. There is a post on the site that covers it as well. There is a plastic covert hat houses electrical connectors that connect wires from under the flood to the passenger compartment. The rubber seal round the plastic box seems to loose its sealing ability over time.

There’s also a potential leak point where the hood release cable passes through the firewall near the same spot.

Cleenlivin said:

If your car has a sunroof it could be clogged drains, if not (at least on my 04) the leak could be from around a plastic cover beneath the drivers side of the plastic cowl. There is a post on the site that covers it as well. There is a plastic covert hat houses electrical connectors that connect wires from under the flood to the passenger compartment. The rubber seal round the plastic box seems to loose its sealing ability over time.
There’s also a potential leak point where the hood release cable passes through the firewall near the same spot.

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Thank you! My 05 wagon does not have a sunroof. I will investigate the areas you described.

I found the original link in case you weren’t able to.

http://http://forums.tdiclub.com/showthread.php?t=198937&referrerid=82874

Installed a new shifter "cup" bushing and dieselgeek first gear getter, readjusted the shifter cables, and admired the improvement. Got to test out the now properly implemented lift pump. The results gave me a big grin Next project is to grease the HVAC blower to get rid of an intermittent squeak/squeal when speed "1" or "2" is selected.

Over the last 2 days I have gotten a lot of little things done on the car. First was to fix a rattle I was having intermittently. Turns out the heat shield over the down pipe was almost laying on the pipe. So happy to have that noise fixed.

Next was a bunch of interior work. Pulled the center console and installed one with the cup holders in it, so I don't have to use the crappy ones below the vents.

I also put new foam on the blend doors. Man what a PITA. But seems worth it already. Now when I put the vents on the floor air actually goes on the floor! Instead of blowing equally out all vents. It had been that way for at least a year. Obviously getting worse as time went on. The door that controls where the air goes had NO FOAM LEFT ON IT. The temp control door wasn't as bad, but still had 3 holes with no foam, I think. But all fixed now.

While I was behind the radio I hooked up the Bluetooth mic. Should have done it 3 years ago when I put the new radio in but just didn't. Oh well. Now I can have hands free calling.

While I had the interior torn apart I also "hardwired" my dash cam. Up until now I was just plugging it into the power outlet below the radio.

Man that was a lot of interior work for me. Frustrating at points but I'm glad I got it all done now.

03 shaker said:

I also put new foam on the blend doors.

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Does this mean you took the dash out in order to get to the air box? did you have to mess with the refrigerant lines?

Finally non-stock! Baby-stepped into it with Dynamic EGR.
I swear she felt better while we drove away after.
Next up is DRL delete woot! ~getting crazy~

Point of interest...I'm still using the same headlamps they installed at the factory.

Look out, he's on a roll! Didn't want to try the stage 1 tune?

I actually do, but want to get some minor work done first and also wait for another paycheck Yeah, I'm not the smartest shopper heh.

Kidflyr, why did the lift pump make any difference unless you have a super aggressive setup? The injection pump should be able to supply all the fuel you need. I have a stage 4 tune and I get plenty of fuel without a lift pump.

mrfiat said:

Kidflyr, why did the lift pump make any difference unless you have a super aggressive setup? The injection pump should be able to supply all the fuel you need. I have a stage 4 tune and I get plenty of fuel without a lift pump.

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Run a log on VCDS to check actual versus requested fuel at WOT in a redline pull in 4th gear. If the IP can't meet request a lift pump will help. When I was running PP502s with an 11mm pump the lift pump made a difference in track events. But for most uses, it's not necessary.

However, a lift pump is a great addition to the ALH. Quicker starts, easier fuel filter changes, and it takes stress off the expensive IP and can extend its life.

BakoTDI said:

Does this mean you took the dash out in order to get to the air box? did you have to mess with the refrigerant lines?

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Yeah I took out the glove box, console around the shifter, trim panels under the steering column, then I could remove the radio and hvac control stack. That gets you to the outside of the "plenum", which has to be removed. I mostly followed the advice in this thread http://forums.tdiclub.com/showthread.php?t=413341 with the exception of splitting the plenum. I was able to get it out together. Although it was a fight, and I had to remove one of the supports for the dash, but I got it out, and back in without taking it apart.

It's a lot to take out, but still doesn't qualify as removing the whole dash.

That might just muddy the waters, but once I got into the dash, the pics in that thread made more sense.

My fueling and air arrangements are pretty mild: DLC764 nozzles set at "stage 1" calibration, Injection Quantity set at 5.0mg, 10mm injection pump, 1.8t pancake pipe, and AARodriguez/Tunemyeuro side mount intercooler. Stock VNT-15 as far as I'm aware, and almost 230k on original clutch. No Tune yet, still deciding which one to go with and building up the hardware before a software decision is made. 11mm pump/whether I can acquire one, which clutch/flywheel arrangement, and whether or not I want to install a PD150 manifold, and possibly PD150 turbo inlet pipe are upcoming decisions I'm reading up on prior to any tuning.

The lift pump seems to have helped reduce the tendency to stall in situations where too high a gear is selected, such as the accidental 3rd gear starts I was prone to before some much needed shifter maintenance. Part-throttle roll-on response seems slightly hastened, and startup occurs with a shorter cranking period. I'll admit I muddied things by removing the snow screen while I had the engine bay apart, though my experience is it made little to no difference removing the snowscreen on my gasser mkiv.

I suspect that the apparent uptick in accelleration I'm perceiving after the addition of the lift pump may actually be an indication that it is/was time to install the new fuel filter I have waiting at home. Easier priming of the fuel filter with less tools/cleanup and any enhanced resistance to stalling (teaching someone to drive manual shift) were the main motivations for adding the lift pump, and in the background, the notion of laying the foundation for more aggressive fuelling in the future.

I need to read up on the logging features of VCDS and gather some fueling data as suggested.

EDIT: My the fuel filter was pretty old, manufacture date of September 2006, unknown date of installation. New fuel filter continued the trend of quicker, smoother power delivery. Filter change and fuel system priming took under ten minutes with tools list being a #3 + screwdriver and hose clamp pliers.

Thanks for the feedback on the lift pump. I have 3 ALHs without lift pumps and they all seem to have very smooth power delivery. Just wondering if I need a lift pump, but it sounds like I don't.



I drove 300 miles to Amarillo, Texas yesterday in my stage 4 ALH wagon and got 40.1 mpg. I average 32 mpg in the city. At least in my experience, the more aggressive the tune/nozzles, the poorer the FE you get. (but way more fun!) I got 41 mpg in this same car with a stock tune and an auto tranny driving from Seattle to Albuquerque. (since been converted to a 5-speed) Everything on my wagon is spot on to the best of my knowledge. Not sure how people are getting higher FE numbers with this same tune.

kidflyr said:

1.8t pancake pipe

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Can you show us a pic of the modified piping for this? I have 1.8T pancake pipe sitting in my garage for a future mod, just haven't taken much time to see what other parts I will need to make it work with my stock VNT15.

BakoTDI said:

Can you show us a pic of the modified piping for this? I have 1.8T pancake pipe sitting in my garage for a future mod, just haven't taken much time to see what other parts I will need.. .

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http://forums.tdiclub.com/showthread.php?t=334241&highlight=1.8T+pancake+pipe&page=2 see post #17 for pictures (not mine) and #26-29 for some discussion of parts. I too used the 2 inch hump hose and T-bolt clamps. The T-bolt clamps "sized for 2 inch silicone couplers" from the frozen boost store were extremely challenging to fit on once a pipe is in the coupling. I bloodied up my hand pretty thoroughly trying to get the T-bolt started. If I were to do it over I would order both the "for 2 inch" clamps and some "for 2 1/4 inch clamps for the 1.8t pipe as well as any additional T-bolt clamps I could put on the intake tract. One of the two " for 2 inch" size clamps I wound up using as planned on the connection of the hump hose and factory VNT15 hose with metal end, and used the factory spring clamps on the other connections. Since I had it and it fit for me, I used the other "for 2 inch" clamp on the elbow to egr connection.