[T3] Bad day at the (FI) office

[Daniel Nohejl]

So on Friday after work, I had a minor issue in that the motor was bucking/skipping under hard acceleration and seemed kind of inhibited in general until it was warmed up. It was an unusually warm day for this time of year…..75* if that makes any difference. 

Naturally, I looked at the stupid AFR gauge but #’s were so rich that they seemed impossible: between 7 and 9 whereas by most accounts I could find online the car should have been undrivable, belching black smoke out the exhaust. This got me thinking that perhaps the AFR gauge is having an issue. We pulled the plugs yesterday and they were pretty clean but for #’s 1 and 4, both of which were half fouled and half white for some reason. If the motor had been so rich, the plugs would no doubt have been fouled. We have plenty experience of that from when we first got the car and before we realized it had the wrong brain in it…..the plugs would be jet black within minutes of idling. Anyway, here are the plugs after we pulled them yesterday:

http://images.thesamba.com/vw/gallery/pix/1486226.jpg

In the end, we kept 2 and 3 and replaced 1 and 4. Of course something iffy happened when re-installing the plugs…..After installing #2, I couldn’t remove the socket because it kept fouling on the eyeglass tin so we had to back out the plug again and it came out with a bit of metal on the end!! Not tons, but enough to know that something wasn’t right. However, we must prayed to the right gods because we were ultimately able to get the plug back in and snugged down using another socket. This was on a stone cold motor and with a good amount of oil on the threaded part of the plug. I guess anything can happen with old heads! I fear that the next time we remove that plug, a bunch more threads will come out and we’ll have to use an insert. Perhaps we should just take a nice spring weekend day to pull the head and do an insert before the hole goes bad at an inconvenient time!

So, regarding the alleged richness, I tried removing the TVS and full load switch plugs as well as the wire from FI harness to the starter but that had no effect on the AFR. I also went through all the tuneup stuff but the valves and everything was fine.

We’re now driving with the MPS more or less back to its original position and no resistor on the CHTS. This has had only the slightest effect on AFR but now the gauge is clearly under suspicion. Weird thing was that in changing the MPS back, the idle AFR would lean out as expected and then after a few minutes of driving would go back to very rich. I’m giving very strong consideration to removing the AFR gauge and using other indicators to evaluate how the motor is doing. 

Then, we finally got around to taking some videos of the rear end bounce….one from each side. The left side squeaks noticeably when pushed on. I got under the car while Jessica pushed on it and the squeak seems to be coming from the shock. I’ll have to remove the shock and see if the squeak goes away or not. Otherwise, the trailing arm bushings look fine and nothing else looked out of order though it wasn’t too comfortable or roomy under the car with someone pushing on it so maybe I’ll have to look again. 

Right:

https://www.youtube.com/watch?v=JrW_Bkr3iHs

Left:

https://www.youtube.com/watch?v=X8i_9a_iZhI