I can feel the finish line getting closer. Or at least I think I can. It might just be gas. Or gas fumes.
I apologize for the lack of pictures on this update. I’ve had a bit of the “red mist” on this project. And very dirty hands. And I keep leaving my phone weird places. Must be gas fumes….
After my last update, user Nibble suggested my sluggish operation could be a faulty wastegate. Having done 0 work to the turbo system, I was also inclined to believe this. I was gradually warming up to the idea of the problem being exhaust related, so the wastegate fits too.
That said, the first thing I checked was timing. Unfortunately, one consequence of sitting so long is I couldn’t actually read any of the markings on flywheel. A wire brush and some contact cleaner (while the engine was running) solved this. I hit it with the timing light and was pretty much spot on. Only off by about 3 degrees. Unlikely to be the problem.
Next up was to check the wastegate. I stated the car and revved it and didn’t see any action from it, but that didn’t really prove anything. What I DID see is small bubbles in the WD40 I sprayed in the actuator arm. Possible further signs of a clogged exhaust? Well let’s keep going. I disconnected the wastegate from the APC solenoid and blew 10PSI of air in there. The actuator extended, no problem. Ok… next up…
Following the instructions in the Bentley, I checked the APC solenoid. Though I’ll be the first to admit I have very little idea what it is actually doing, it DID seem to be working as per the instructions. Next.
Now I needed to either remove the CAT or the O2 sensor to see if that helped. Neither sounded appealing, but I opted to try the cat first as I didn’t really want to bypass the turbo yada yada yada…
With the exception of one bolt, the whole process was pretty easy. I mean… I got a lot of PBBlaster and rust in my eyes… but that is par for the course. The (surprisingly heavy) cat came tumbling down, introducing me to another fun problem: with the center pipe now unsupported the whole back half of the exhaust is hanging down. Great.
After a couple of failed attempts to fix the hanging exhaust, I decided to inspect the cat. I’d been putting this off because I knew it would be fine. Because that is how my life works. Guess what? Yeah… pretty much perfect looking despite being from 1996. That said, I’ve never actually seen the inside of a cat before this… so meh?
After trying to completely remove the back half of the exhaust which is both in surprisingly good shape and very well put together, I gave up and decided to wire the exhaust to the heat shield hanger bolts using bailing wire.
Now… on to the test drive.
It was… underwhelming. And overwhelming. The din of a turbo four running straight from the headers is… substantial. Mostly I’ve never heard a turbo so clearly in a passenger car. Whoosh! That said, the performance wasn’t good. The engine still felt like it was holding back and really didn’t want to rev… and that is when things get weird.
After conceding defeat and not wishing to irk the neighbors more than I already do, I decided to cut short the unsatisfying test drive. In the driveway, I knew I needed to regroup and reassess possible fault conditions. Make lists. Think things through. Don’t just start fucking with shit.
Instead I started fucking with shit.
Out of irritation and anger I leaned out the mix and headed back out. It felt… better? Ok, how about a little leaner. Better? Leaner? Better. Leaner? Ok now the engine really wants to die… but it strangely backfiring on deceleration… maybe bring the ratio back up a bit.
So the question is now: did the removing the exhaust change anything? Was it just the mix that fixed it? Or did I just finally work through all the bad gas that was stuck in the lines, fuel accumulator, and pre-pump chamber? How much fuel could that be? Should I just replace the exhaust anyway (it is in REALLY good condition).
I don’t know the answers to these questions. I do know that the car is now drivable, if loud, and that feels… really odd. Like… REALLY odd.
Doggo for your time.