Am I on the right track with P1316 code?
 

Hi all, my recently acquired 97 SE with 138,000 miles has the 1316 code. It came with it. I guess that's one of it's options from the factory?? :D

Anyway, I'm moving down the list of things to address it. Have searched up a ton of info, and done lots of the recommended service items. Here's what I've done so far
[LIST][*]New Denso plugs, gapped .035[*]New 8mm wires[*]Cleaned MAF[*]Cleaned TB and IACV[*]44k in the tank, but hasn't really run too much of that yet[*]Seafoam induction[*]New oil/filter

I'm not sure what's going on with this. It didn't post my whole thing, and screwed up the BBCode. WTF? Here's what I meant to post... Sorry!

Hi all, my recently acquired 97 SE with 138,000 miles has the 1316 code. It came with it. I guess that's one of it's options from the factory?? :D

Anyway, I'm moving down the list of things to address it. Have searched up a ton of info, and done lots of the recommended service items. Here's what I've done so far

• New Denso plugs, gapped .035
• New 8mm wires
• Cleaned MAF
• Cleaned TB and IACV
• 44k in the tank, but hasn't really run too much of that yet
• Seafoam induction
• New oil/filter

So far, none of that has yielded any big improvements. Here are the symptoms:

• Very rough idle at start
• Won't stay running until it's warm
• When driving it won't accelerate when the pedal is floored... kind of stalls out at about 2k indicated RPMs.
• Smells rich, and kind of a stumbling idle once it stays running

So I've got new upstream O2 sensors ordered, and will have them Monday. But I'm thinking, due to the lack of accelerator function, I should also be looking at the truck's TPS. Does that sound right? Is that cleanable or just replace it? I figured I'd go with those before looking at fuel injectors.

What do y'all think?

Throttle Position Sensor - failure of the sensor will result in poor idle and lack of throttle response. If failure occurs in the closed position the engine will only reach 1750 rev/min when the ECM will initiate overrun fuel cut off. Replace it, there is no cleaning a TPS when it's electrical fault is due to a worn contact disc.

quick update
 

I got the new throttle position sensor installed last night... for anyone who's interested now or in the future after i reconnected the battery and fired the rig up with the new sensor in place it took the truck about 5 minutes of running all weird for it to figure itself out.

It bogged down and cut out. Then it idled at about 2k indicated. Then it slowly sort of leveled off to idle at around 1k. Then I was able to drive it around a little. Initially had a couple small backfires, but as it ran it smoothed out a lot. I drove it for about twice the time it has taken previously for the Check Engine light to come on, and no light came back on. So far. Hope it's not reading this. :D

Anyway. That's my experience w/ the TPS. I'm not sure if I "need" to replace O2 sensors at this point or not. I guess at some point I will... heh.

Warm idle is 675 +/-5 rpm. 1k is a wee bit high. Install the new O2's, they're most important sensor on the truck.

O2 sensors
 

So, uh... how exactly do you reach the front O2 sensor wire connectors?? Or do you just splice in the new ones? ;)

Many pull the coil pack to get to them. Others practice yoga.

Seriously one of the dumbest most idiotic frustrating things to do on the truck...why is the plug you have to remove the one that has the tab for the mount? ??! The plug not only ensures you have to use two hands (or at least one w a long flat head screwdriver in the other) but it's also extremely hard to reach! Every single time I have to do that job I curse the truck. Why oh why couldn't they mount that plug on the fire wall???!


rant over

Got the O2's in, and had 'er running great around the neighborhood for a little bit. Then driving to the E test place, she threw a P1177. So I'm gonna test fuel pressure. Looks like an original fuel filter, so I'm planning to replace that. If pressure is low, is that the right thing to do first?

If pressure's NOT low... um. Step 3, PROFIT!! :rolleyes:

You haven't driven it enough to loose the LTFT too rich Fuel Mass Flow Rate with more drive cycles. If it was Short Term then I'd say you have an issue. Long Term is much less about the now, much more about the past and the past you had bad/lazy O2's installed. Let it ride for awhile. Too rich means it's getting too much fuel/not enough air. Not enough air can be MAF, fuel pressure too high, former O2's, Fuel Pressure Regulator - blah, blah, blah. Give it a minute to measure more drive cycles before diving in.

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?

Will do that. Thanks for sticking with me on it!

One way or another I'm getting this beast on the road!!

I've been in your shoes. Keep a clear objective mind and the problem will hit you between the eyeballs. Can you check your fuel pressure as well. Check it with the ignition in pos II, motor not running and if you can check it with motor running. Be careful when it's running..... no need to become a Tiki Torch over a Rover.

No problem sticking around, always worth it.

Here's the latest...

Fuel pressure at the rail with ignition switched on is right at 38 psi.

I checked the MAF again and gave it a shot of cleaner, and double checked a couple of the throttle/idle/air sensor plugs.

Now she won't stay running at all.

Nevermind. It's running. But still idling at 1800ish. Turning on accessories makes the idle fall several hundred. Turning them all off makes it go back up.

Time to point fingers at the IACV?

Pretty high, the IACV aint a cheap part and you'll definitely have to have the ECU reset when you replace it otherwise it will continue to run high. I would talk to a garage about the reset with your current IACV and if that doesn't work if they'll not charge for another reset with a new IACV. Doubt they'll go for it but nobody's gonna get a cramp over trying.....

I guess your down for the hunt-n-peck method of trouble shooting......

Ha! Well... I wasn't hoping for hunt n peck. But that is what's going on I guess. I was hoping I got one that could be fixed by the normal crap I've read on here about 1316 codes.

No big deal. I come from Jeeps. These things don't scare me!!! :D

There is nothing normal here aside from the crap. It's all an illusion I assure you.

Could you do this like vsop4me did with his Fuel Pressure Regulator; https://landroverforums.com/forum/di...07/#post539188

Thanks IHScouts. Check the FPR? My fuel rail pressure was good. Although I did not check it with the truck running... so. That.

Mulling this over today I've been thinking a few things:

1) I should inspect fuel injectors for dirtiness. (Not smelling fuel or anything which happened when my Jeep XJ injectors failed)

2) Check downstream O2's for fouling. I just put brand new upstreams in. If the downstreams are in bad shape would that also be a contributor to this issue?

3) I installed Accel universal plug wires when I was doing the tune up because I've put them on a lot of rigs over the years, and they were on the shelf at Advance. Everything on here says to use Magnacor. I've noticed a few threads now that talk about the importance of the exact correct wires. Did I screw up there?

4) I'm doing all this as an excuse to avoid potentially WAY more expensive options.

Did the motor run like this when you bought it?

Sort of. Had the 1316 code. It ran rough, but did not have the high idle. It looked like it had old plugs and wires. I came on here, and researched.... thought I was gonna get away with a tune up and be running good. Ha!

The high idle is probably from the IACV cleaning. Not only do you clean the pintle (pin) but the port seat as well. If the seat aint shiny bright silver color it aint clean.

Anyways....... you have not found the problem yet if it's still basically running like crap.

Check the wires going to the Crank Position Sensor and you might as well check the sensor cuz it's there and a whole bunch of fun to remove. Be careful. You want to see the tip, if it looks unmarked your good. The wires and insulation because of the proximity to the exhaust have a way of becoming stripped of insulation and grounding. There's a method to my madness and I have to rule out one sensor at a time and you'll get acquainted with your Rover like never before on a Heep.

I hear you brother. And again... I really appreciate it. Definitely at this point I wish I had a liiiiittle more experience with these beasts. Oh well... I wanted to get my knuckles dirty on a truck again, and here we are!

Yep, here we are. Did the previous owner take the truck into a wrench palace before offing it? How long did they own it for? Did they spend any money on keeping it running?

PO had bought it to replace his former '98 that he wrecked (which I'm considering buying for parts). Said he didn't have it too long, and no history of recent maintenance. He Thought it needed cleaning out and a tune up. I know it's a Colorado truck.

I had to tighten up the valve covers and exhaust flanges. It appears to have newer valve cover gaskets. Aren't the aftermarket ones rubber and have the tabs that stick out? Or is that factory?

A bunch of other stuff seems original. Like the O2s for example.

Well sure enough... I fired the beast up just now and I have it idling right on point just like it supposed to: right around 700 rpms.

And the fuel pressure while idling is holding fast at about 32 psi. I checked fuel pressure again because i realized that I had read it wrong the last time. So now I have confirmed that fuel pressure under idle is 32 psi.

For now it's idling way it's supposed to. Also the wires to the crank position sensor are in good condition.

Incidentally, I had just called a Land Rover shop and asked if I could bring it in on Monday morning. Beast must have heard that.

Sorry I posted too soon. The truck is still running bad though. :D when I turned it off to remove the fuel pressure gauge and started it up, it was back to idling at 2000 rpms and driving on the stree like crap. Then I turned it off and on again in the idle came back down. Still think I'm gonna take it in. Get a proper diagnosis.

I'm good with taking it in, enough putzing around. If we haven't uncovered the source in 37 posts something is beyond our reach without a hookup.

Yeah. I agree... seems like mine isn't like the 20 other threads I e read about this issue.

Also the tech I talked to said it was really odd to get a 1316 without also a specific cylinder misfire or some other trouble code. He said they'd be able to get more info with their machines than a basic OBD2 scanner.

That sound right?

Slightly off topic... it's JCs British in Englewood CO. anybody on here have experience with them?

I don't know much about those Accel wires. If your looking for a great quality set of wires in the future try Kingsborn. I've run them on my last 3 trucks. They are great quality and won't break the bank.

I've been watching your thread. Hope you get it sorted out soon.

Well I dropped 'er off at JC's last night. Interestingly... she drove just fine all the way over there about 30 minutes. No codes popped... No excessively high idle... pretty smooth acceleration.

Any chance that a little 44K finally working its way through the system has "cleaned" up some "stuff"? Can I be that lucky?