Spring tuneup

Left the heep parked all winter. Then without really doing much except for filling the gas tank, I started driving it again. Most of the time it ran fine, driving around town and to/from work. It idled a bit high, around 1000 rpm, but I didn't think much of it. Then I took it out on the trail. After idling and crawling for a while it started to run like shite, idling rough, stalling, but smoothing out over 3k if I could get it up there without stalling. Soooo...

Hooked up the old meter to the O2 sensor test pigtails I thoughtfully added to my harness. Pegged at lean. But the olfactory exhaust gas analyzer read rich. WTF?

Inspected meticulously for vacuum leaks; none found. Tightened intake and exhaust manifold bolts just in case.

Used the hose in the ear method (Thanks Joe Peters, that is the best tip!) to find a HUGE exhaust leak in my paceshitter downpipes; brought it to the shop, had some welding done, threw on some muffler putty, exhaust leak killed, at least for now. O2 still pegged lean, exhaust still smelling rich, idle unchanged.

Ok maybe I should, like, actually do some annual maintenance. Went down to Advance Vato Parts (the only parts store open late in Barre VT). Got an air filter, plugs, cap, rotor, and O2 sensor (when did O2 sensors get so cheap?)



Those look OK. Maybe a little carbon...



I was going to keep the old O2 sensor as a spare, except that now I'm pretty sure it was the problem. And I accidentally broke it open. Big WTF on the element. What's with that pitting? I'm guessing that's what caused false-lean readings in the face of rich combustion.


I'm sure this wasn't helping either. Damn mice. The pleats are full of crud. I should know to check this after it's parked all winter...

So now it runs great, idles at ~600, O2 reads stoichiometric, more power, etc. Here's to hoping it runs better next time on the trail :cheers:

Found a nest and 40 acorns in my wifes focus last week - runs alot better now

veedubshafer said:

Found a nest and 40 acorns in my wifes focus last week - runs alot better now

Click to expand...

Ok you win.

n1ywb said:

Ok you win.

Click to expand...

HA, yeah I was totally surprised.

N1ywb: is that "squeek" gone from under the hood?

I found the contents of a whole sack of unshelled peanuts in a customer's air filter housing once while working at valvoline instant oil change. Customer: "haha, I was wondering where those went..."

I actually forgot a funny story from two years ago. I had again parked the Jeep all winter. When I went to start it in the spring, I noticed a mouse nest under my hood in my funnel I keep there. Whatever, I thought. I drove to the gas station. I get out and walk away from the jeep, and I turn around and see a big fat mouse drop down from my engine bay and scurry off into the bushes.

Now that I think about it, that nest in the air filter could have been his, I haven't checked it in a while...