That's just it - it seems to run just fine, idles just fine, everything is just damned fine. Except for really crappy MPG of course.


And then this excessive emissions fault, no idea how that happened. Sat all weekend and then bam, there it is.

 

Well really it's not running fine.......... lousy fuel mileage but it appears to run normally as in it doesn't idle or motivate like crap. That's good..... kinda sorta. I think what is happening is the Techron woke the ECU up. Does your scan tool shoot you pending codes too? P1316 probably was near boarder line for the ECU but not enough to trip a code yet. Simplistic but I'm sure you get the idea.

This is from the GEMS OBDII.....

Excess Emissions
The percentage misfire (MF DIAG PCENT MF EMISS) is calculated in blocks of 1000 revolutions of the crankshaft using MF DIAG FIRE COUNT
EMISS I as the revolution count. If the misfire rate is high enough to exceed specified emission limits, cylinder identification takes place and a misfire
emission fault is present

We already know the motor is getting too much fuel so if you can bum a MAF and replace the IAT at least the sensor side of things will be in order. There's so much on the mechanical side of the equation though, like valve condition, timing (chain/gears), carbon, and so on.....

 

I haven't seen a Disco 1 in 6 months at least. I think I may have a line on a used and tested one though.


The gears, valves, all that was redone 20k miles ago...it could have all gone to **** I guess, but -shouldn't-


Carbon build up could be an issue, granted.

 

I'd lean toward the MAF as well. I'd also do an adaptive values re-set as soon as the replacement is installed.

 

Yeah I've been trying to figure out how to do that. Some dude on Discoweb came up with a program that will do it with a cheap OBDII scanner, but not the one I have, so I guess I need to buy a new one of those, too.

 

Not sure if it's just my engine, but these things produce a good amount of carbon. My machine shop had to redo my piston rings after about 3-4k miles and said they haven't seen this much carbon build up in such a short amount of time...

 

And now a P0300 random multiple cylinder misfire code.


The strange thing is my codes only show up on start up, no other time that I recall.

 

These are sloppy little engines, not efficient for anything but a boat anchor.

 

Nothing strange at all that's because as I copied here it starts counting at 1000 revs - idle speed.

 

I need to go back to 2 stroke motors.


So if there is a random cylinder misfire at start up, why wouldn't it continue as running and throw another code? I cleared the code, started up, drove back to work. No code.