Now that the CEL is no longer illuminating with the P1391 code, I'd like to move on to mileage. Getting the crankshaft to TDC to re-index the distributor, I noticed that the top of the #1 piston is dark brown / black. Not black black like soot, but close. With the history of neglect, and all the black soot I cleaned from the throttle body, I’m GUESSING that it has been running rich(?) for quite some time, expect that there are other parts that need to be similarly cleaned or replaced, and wondering what else I can / should / shouldn't do to rectify the problem?

I've already replaced all the ignition pieces parts, fuel filter, and O2 sensors.

The only non-stock variables (that I'm aware of) are a K&N air filter (recently services) and 215 / 75 / 15 tires.

Thanks
goodyoleboy

 

Default ATTENTION ALL USER: Please read before posting!!!To all users of CF:

PLEASE, before posting technical questions, take some time to help others out, by adding details in the user control panel. There's 2 ways to do this. First, in the upper left corner on the front page of the site, is a menu button labeled UserCP.




After you click on that you'll see this menu:





Please take the time to click on the highlighted sections and fill out the vehicle information for your vehicle. The signature link is also helpful for any additional information like mods done, links to your build or other vehicles owned.

This helps EVERYONE out by informing them immediately about your year, make, model, etc.

These details are necessary for responders to accurately answer your questions without guessing or having to ask what are the specifics of the vehicle you are referring to. You can add these details easily and permanently by creating a signature or adding your truck details to your existing signature.

5 minutes of your time doing this now will save a ton of time and effort later.



Thanks!!!

CF staff

 

Cruiser 54: I can take a hint. :-) See info update.

goodyoleboy

 

BG 44K in the gas tank. Nothing like it.

 

Yeah, did the BG 44K too. It resurrected my brother in laws car he was ready to trade in. Apparently it runs fine now. How long does it take / should I wait to expect improvement?

Just filled up today, got 18.5 MPG driving like granny, gradual acceleration, cruise control, mostly flat level ground, never above 65, on the highway.

Any other ideas, goo's, potions, spells, incantations, quit yer *****in, or ________???

goodyoleboy

 

Prius

 

Hilarious :-) ,but Hades will freeze over first ! ! !

I've got a 35 MPG rice burner for mileage runs.

Thanks

goodyoleboy

 

So, . . . I've seen Marvel Mystery Oil recommended for the crankcase elsewhere on the forum. Yes / No OR _______ ? ? ?


Thanks
goodyoleboy

 

You're getting 18.5 and you're complaining?


Talk about high standards lol

MMO is great for sludge buildup and quieting down noisy lifters.

 

Okay, stop whining, I get it! :-)

My friend with the no cat configuration is getting 22.5.

I just want to do whatever I can, short of extensive machining / modification, to get whatever I can and running as clean as is reasonably possible.

Thanks

goodyoleboy

 

LOL its all good just giving you hell haha

I get between 14-17. Not bad for a lifted brick

 

As my sister always used to say "If I didn't harass you, you'd feel neglected." :-)

MMO coming up! Couldn't hurt, right !

Which reminds me, . . .

Is carrying around the 40 lb front bash plate worth the aerodynamic / potential fuel economy benefit it theoretically / allegedly provides?

Thanks
goodyoleboy

 

6 of one half dozen of the other

Any aerodynamic benefits are probably trumped by weight.

I had the skid plate up front at one point. I gave it away, it was always in the way when doing maintenance. Not worth it IMO

Do the MMO a couple of hundred miles from your next oil change. Then when you change your oil, you're good to go.

 

Just got back from a 500 plus trip Pueblo to Moab and back averaged 22-23plus MPG going 60-70MPH. The speed doesn't seem to make much difference, but any rapid / hard acceleration does.

goodyoleboy

 

Famous last words 🤣

And in regards to aerodynamics...there is very little of that in xjs, nor any gain or loss😆. Just like 12hole injectors...it looks awesome but in real life?
Your right foot will determine most of the speed your wallet empties

But 18.5mpg (you made me fo the conversion)...I don't think I've ever even been close to that LOL

Oh you'll never guess what's on my lot here now between all the 4wd's 🤣