I'm probably going to go down the rabbit hole a bit with these next few posts and if this isn't already long winded it will likely get there, so consider yourself warned. At this point in the build I am in far enough to disclose the details even if they may be unnecessary or a bit humbling, for the sake of understanding the situations and potential benefit. Maybe we learn a bit from these builds about what to or not to do, or just a new idea, or even what we already new or should have known or done better. Maybe there's something constructive to add from hind sight, or maybe not and stuff just happens. I'm always trying to improve my methods and sometimes a good learning experience helps remind me to consider if there is a better way.
Regardless, the situation of continuously loading up the 20 year old 100 with as much as I can fit in and tie down to it, and taking it out to remote rough terrain can be taxing at times on the individual components and the sum of these parts, passengers and driver included. The rewards are multiplied by the time we have them, but at moments it seems like a precarious balance with chaos. Fortunately, I have been lucky and I hope that holds, as I try to be prepared and know that things wont always go as planned. Yet I still plan and this trip went much different.
We started planning on a group of usual suspects making a trip south to Arizona. Then things changed and a couple cruisers couldn't make it and another decided to meet up along the way. I did the usual pre trip inspection, fluid levels check, threw in a new air filter, loaded up the usual tools and went through the spare parts. I added a new brake booster accumulator to the loadout as I have been thinking about how a potential failure could leave a vehicle stranded, unsafe, and a replacement might be inconvenient to source. I usually travel with a few other 100's and though mine has been working well, somebody else might need it and though it isn't ideal to change on the trail or some town, with enough brake fluid its definitely possible.
I have noticed a bit of a fuel vapor smell on long drives on hot days and though it hasn't been an issue during the winter I expected some long warm days ahead and thought I might try another remedy to this situation. I know this isn't all that uncommon on a 100 series and mine isn't all that bad, but I'd like to get a better handle on this issue. It might be a saturated or degraded evap canister, but there is something about the current design that bugs me. It seems like there is a drain hose on the drivers front fender that eventually vents to open air. I suspect that is the source of some of this smell. I dont like the idea that it vents to open air, but I realize that excess pressure has to go somewhere. I prefer the idea of the purge vsv sending it back to the intake so it can be burned, so I thought I'd try to run it into the evap test T fitting. I figure it still has to go through a small filter and then only when the VSV is active will it get burned, so it wont introduce debris or cause a vacuum leak. I removed the Schrader from another T that I have and installed it with the evap drain hose going in to it. That way, if there is an issue or I get and evap DTC, then I can disconnect the hose and just cap the fitting.
Then I drove around for a few days and filled up with gas before leaving town. On the way down south, engine performance began to suffer along with fuel mileage. So we pulled off for fuel and I checked for any pending codes, none found, I returned the evap hose to the factory position and capped the fitting. Not seeing anything else unusual, we continued on. Gradually the condition got worse and as we finally made our exit near St. George, it was apparent that Legusy wasn't feeling well. We stopped off to visit some family and unloaded and I started to proceed with the suspicious case. Now I had a P0300 random misfire DTC with the light on and under hard accell the light was flashing, which did not seem uncommon for a rich misfire, though I know it can be hard on the catalyst. The catalyst can usually take a flashing check engine light for some time. I didnt have any other codes, so I proceeded to try and diagnose the misfire. The fuel trim was way off, and I checked the MAF sensor and it seemed dirty so I cleaned it with no improvement and eventually just replaced it to rule that out. I pulled the plugs and inspected the coils and found one outlier being the #4 plug a bit fouled. I put in a spare plug and a good spare coil. After each repair, I pulled and cleared codes and at this point I had a P0304. There was still no improvement, but I then found a P0302, P0306, P0308. So I wasnt convinced it wasnt a coil and tried swapping them again with another spare and similar results. At this point I wanted to rule out all the coils so I put in a new set of all 8. Still no improvement. No obvious air leaks, audible function of the injectors, and though the symptom was somewhat consistent, it was more so under load and the cylinders were firing at some point, I had ignition. So I did a compression test knowing that the valves had all been in spec a year ago when I did the an extensive timing belt service. Compression was good. I tested the fuel pressure too and it was good. Then I started thinking about the misfires common to the same bank and how much I doubted that the cam timing was off. But I had to rule it out, even so, all these issues began after filling up with gas, so I replaced the last bit of fuel with some ethanol free and no improvement. So I finally pulled the cam timing covers. But the timing was spot on.
So I though darn, I've spent most of a day chasing this issue and I probably should have known better. But yet I expected a catalyst inefficiency code before a failed catalytic converter and this one would have to be completely plugged. But yet it was probably getting more and more so with the misfire due to the engine not being able to move exhaust and the passenger side cats were still original despite the other ones being replaced before I owned the vehicle. Sure enough, after I pulled the pipe off, I couldn't get any air to flow through it, there were all sorts of pieces rattling around inside and fine metal bits poured out like sand though that didn't seem to make it less clogged. A leaf blower would not push air through the pipe. So I called around and expedited a replacement for a reasonable price and installed it the next day, with new bolts washers, lock washers nuts, gaskets etc..
Problem solved. so far. I wondered if the evap hose change has sent too much vapor into the engine to overload the catalyst. I know people say that cats don't usually go bed, something causes them to fail, but with the engine running well again and the other cat seemingly fine, I suspect 20 years of use caused this one to fail eventually breaking apart inside. sure the catalyst would still heat up, but it wouldn't flow air and of course the Exhaust shop says they see a lot of clogged cats. Of course, now I hear that. Anyway, I'm now set to go and my friend
@Moody that has been camping around offering support and waiting to meet up for this trip is having issues with his 100 and makes a return trip home. I have been so eager to proceed with this trip and Legusy is ready to go so we load beck up and head out to the vast expanse of Arizona solo.
