Quite a lot of connections still, well, not connected, and this vehicle has a sketchy history. Anyone got any experience of rough-running VAG 1.8T engines? Am hoping that the problem will fix itself once the engine's fully together, but the old one ran rough too - in particular, the idle was all over the place. We've got a replacement bare engine but things like the throttle body, vacuum lines etc have been moved across. It's gremlin-hunting time, I think!
Well, the gremlins are still here, though I've got a diagnostic cable on the way now to pin down a misfire the easy way. Hopefully.
In the meantime, I've modified the old exhaust to suit the new body shape so that at least the misfiring isn't loud enough to rattle windows around the neighbourhood...
I love this thread!
DaveMakesStuff said:Quite a lot of connections still, well, not connected, and this vehicle has a sketchy history. Anyone got any experience of rough-running VAG 1.8T engines? Am hoping that the problem will fix itself once the engine's fully together, but the old one ran rough too - in particular, the idle was all over the place. We've got a replacement bare engine but things like the throttle body, vacuum lines etc have been moved across. It's gremlin-hunting time, I think!
Dave - sounds like its missing a cylinder. on my old 99.5 A4 1.8T, i remember losing a coil pack one time when i went to start it in a grocery store parking lot. just gave up out of the blue and it only had about 40k miles on it at the time. shook like crazy and had a definite rough exhaust note. these engines are known to eat them every once in a while.
awesome project!
Vacuum lines are a major pain with these motors. Second on the coil packs they go bad just looking at them. They have kits out to change them to the later ones out of the newer cars. Headed this way with my car as well. Not the mad max post apocalypse look just the motor. Keep it coming cause this is great.
Loving this....some kind of livery wrap is needed
I could pretend that I'd done lots of careful investigation to uncover a subtle problem that was causing the misfire, but...
...plugged the laptop into it and it wagged its finger at me and said that No.3 injector wasn't working. Realised that No.3's injector wasn't plugged into the loom - the plug was sitting in place but not seated. Runs rather better now, unsurprisingly. The idle still wanders a bit but at least it runs smoothly while it's wandering about. I think we will indeed be messing with vacuum lines and sensors once the turbo and intercooler are plumbed back in.
I helped Julia ran a compression test on it, but in a dog-ate-my-homework moment, someone irretrievably deleted two weeks' worth of footage of that plus the installation of a set of driving lights, 48 hours before the video was to go up, so this has been a bit of an exercise in 1) the art of keeping everything in perspective; it's not actually that important, and 2) disaster recovery. The results are at the link below:
Re-ran the compression test with Julia this week. Did a few other bits and pieces, but mainly have been called away to fix up the house as we might be moving.
And... it moves! It's not road legal and it's not finished, but it moves!
https://youtu.be/qW6fPcbqJRA
Figured the continuing unstable idle (it's running on all four now, but stalls if you blip the throttle) and extremely rich mixture was probably because the inlet and its various sensors weren't hooked up. So this week's job was to turn some scrapyard stainless steel tube into intercooler ducts. That got the engine running much better; in fact, well enough that Julia had a brief go at driving it. Clutch control lesson time!
Made me think of this thread - there was a lifted TT at our last rallycross. I think he broke something on Day 1, seemed like he missed a few runs, but IDK.
In reply to irish44j (Forum Supporter) :
Looks good. Intercoolers might be a bit exposed but if he's rallycrossing rather than rock-crawling then I guess he's proven through experience that it's not a big issue. I do like the tyres too.
Bit of gap since the last video, mainly because I've been working on dull stuff that just needs to be fixed before I take the car to MOT, and "Dave checks light bulbs" didn't seem worth showing, somehow. I did build a ramp and test the suspension flex though. It flexed, though unsurprisingly it flexed like a TT, not like a desert race truck.
And we're on the road at last!
Now we get to find out what gremlins lurk within a high-mileage TT that has been off the road for over a year. But at least now we have the exciting option of being stuck away from home when it happens!
You'll need to log in to post.
