So the new 1177 code is a rich condition indicator? It hasn't had that one pop up until just now. How many cycles does it take to get the computer right on these?

 

Take a couple long drives with the truck and see what happens. Clear the code before you head out while the engine is warm. What condition is the air filter in?

 

Air filter is new.

I just cleared the codes, and drove around. Idle is all over the place. While I was driving the idle was around 2000 rpms, but going uphill there's almost no power. It wants to cut trhottle under load right around 2000 rpms and backfire almost every time.

I stopped and turned it off then back on and it would idle normally for a few seconds and then slowly creep up to about 1300 rpms. And then the next couple times I did that it'd just idle way down and die.

The P 1177 code is gone, but now I'm back to the 1316 misfire which is what I just cleared.

Something is up. You guys sure are super helpful and I appreciate it!!

 

Yep, something is up. I think it's time to start looking at wires/connections. The P1316 is just an overall emissions code, does not pinpoint an exact sensor. The P1177 is confirming over-fueling, again it doesn't point directly at a particular sensor. Your going to have to either take the truck in or go over it yourself to see if some connector or wiring is not as it should be - like two wires shorted to one another and that sort of problem. It's effecting the ECU for sure. Corrosion is usually the culprit.

 

Looking for bad wiring and vacuum issues....

Anybody know what the single port on the non AEL charcoal cannister is supposed to go to? There's no line on it now, and if I plug it with my finger, RPMs Rev up a little.

 

There isn't a line on it ever, the port allows vacuum inside the canister. Keep looking, something is not like it should be. How long have you had the truck - October this year?

 

Yep. Had it about 4 weeks. Bought it thinking it needed a tune up based on visual inspection. Did all that stuff, and I'm still plagued with this random code situation. Can't really drive it too much until I get it registered, and I can't register it until I get these emission codes cleared up.

Seems like so many things could contribute: basic tune up, Ecm flash, VSS, Fuel pressure/filters, vacuum, checking wires...

Is this a lost cause?

 

No, it's not a lost cause, but it is a miserable way of learning what's under the hood because your probably not familiar with LR's. What your looking for is a hack fix somebody prior to you did, a home fix on a wire or wires to say the Inertia Switch or the MAF. It's that type of hack that causes the Engine Control Unit to wig out because it's getting a signal and then loosing it, makes it, breaks it. Without knowing how everything should look from the factory your looking for a needle in a haystack whereas somebody like me could look for a minute and find it easier and probably within a couple of minutes. That's where I think your at with it. Keep looking for obvious hack jobs or any wire splicing that doesn't look like it's original. You noticed the open vacuum port on the purge switch (which everyone finds after awhile) so I know you've got the LR bug.

I'll tell ya from experience, once you find the problem child the truck will run better than ever before.....! The Inertia Switch on the firewall is one device that gets hack jumped allot, check that thing, remove it to check it.

 

I have been looking for those hacked splices and such. Nothing is looking too odd. Almost everything that's visible in the engine bay has oem connections and sheathing. If the inertia switch is the little rubber capped thing by the washer bottle... it's as it should be best I can tell.

Here are a couple other notable things:

PCV was clogged, so I unclogged it today. No change in running though, but it does have a slight effect on idle.

MAF has been cleaned by me. Engine revs way higher if I pull it's plug.

IACV has been cleaned by me. Nothing happens if I pull its plug. Idle stays high.

TPS is new. Nothing happens if I pull the plug. Did not reset the ECM after this. Is that required?

 

If you replace the IACV yes, you'll need a reset. The TPS not normally. If it was idling poorly before the replacement then it's not effecting the ECU. Usually an independent garage can reset the ECU and in Denver there a few around that work on Rovers. Have you checked the wires to the Crankshaft Position Sensor?