1996 disco P1316 WTF?

[Craigness]

I'm about the shoot this thing and get another Tahoe.

I have had it with this 1313, 1316, 305 and 307 code crap. I changed everything. I rebuilt the heads, changed all the engine sensors, checked al;l harness wires and plugs. Spit shined the ecu connectors and the bastard is still buggared.

I did notice that when I disconnect the rear left o2 sensor it runs great for 24 hours! I mean it only has 60% of its overall power but its smooth and stable for a day and then it starts is trip again. Even with the sensor disconnected. check this out, if I disconnect the rear left o2 sensor I get NO CODES set! In fact, when the CEL does come on its not for the o2 sensor but another p1316!

I have come up with the theory that there is nothign wrong with the motor and any of the sensors. The computer is just no designed well. Crappy software or something. I know there was a prom update but land rover will not verify this.

I also might suspect a clogged cat. Would this cause my problems?

Id does seem to blow out the manifold / y pipe gaskets a bit. sounds like a lot of rushing air and hissing under hard load like an exhaust leak under my feet. I know from other cars this indicates a blockage in the exaust. So why would I get misfire codes from a blocked cat if this is the case?

Does anyone know of a chevy 350 conversion kit for this thing?

 

[NVRover]

Not trying to be rude, but aren't you the guy who, in a previous thread, was suggested to repeatedly by experienced LR mechanics to go visit a LR mechanic with a testbook or rovacom computer because these codes require those capabilities to diagnose the problem? If so, seems as if you should follow that advice.

Previous Thread

 

[montanablur]

It seems as though he asks questions and doesn't follow advice.

Therefore being a waste of time and useless trying to help.

I remember early on reading that Dweb only helps if you let it.

He did threaten to going back to a Tahoe... Meaning he owned a Tahoe before, which is in itself very suspect.

 

[alex]

First of all, the rear o2 sensors have nothing to do with engine management at all, and should not affect driveablity in any way. They are there strictly to monitor the condition of the cats--an emissions device only.

Second, it is not unheard of with these vehicles to throw cat inefficiency codes even with new cats and new o2 sensors. Usually, this is indicative of a wiring or ECU problem. Not so easy to fix, but it certainly can be worked around. Have a look at this website

And as far as the Tahoe I have an 05 GMC 2500 pickup that I have put 14K miles on since march, and it has been flawless. I have owned my Disco since new, and it had already seen a ton of warranty work by that mileage. Now it has over 140K and has pretty much calmed down, but the initial quality (not to mention power and comfort) don't even compare.

 

[Chris-St Louis]

Does anyone know of a chevy 350 conversion kit for this thing?

HAHAHAHAHA!!! No Effing way I'm taking this car to a shop to fix a code..... I'll replace it with a small block!

 

[MtclimberVT]

First of all, the rear o2 sensors have nothing to do with engine management at all, and should not affect driveablity in any way. They are there strictly to monitor the condition of the cats--an emissions device only.

I told him the same thing but he would not listen. It needs to go to a dealer. End of Story.

 

[Chris-St Louis]

Random misfire plus odd bank misfires to me means Vehicle Speed Sensor.

If this were my truck, I would swap that out.

 

[RoverChic]

Random misfire plus odd bank misfires to me means Vehicle Speed Sensor.

If this were my truck, I would swap that out.

He did already ...or at least he said he did. Refer to old thread.

 

[Blatant]

And as far as the Tahoe I have an 05 GMC 2500 pickup that I have put 14K miles on since march, and it has been flawless. I have owned my Disco since new, and it had already seen a ton of warranty work by that mileage. Now it has over 140K and has pretty much calmed down, but the initial quality (not to mention power and comfort) don't even compare.

Me, too

I had a 2500HD as a tow rig for my rockcrawler and it always (ALWAYS) performed like a champ. Not trying to disrespect the LR, but to compare build quality and dependability between the two is just silly.
d

 

[Craigness]

The Facts.

ok guys, I have had a lot more rovers than most of you but all series trucks and pre 1992 classics. This is a whole new pain in the ass.

The bottom line is that when I do disconnect the drivers side rear o2 the truck is totaly drivable for at least 3 hours until the shakign and misfires start but when they do it's no where near as bad as it is with the sensor connected.

BTW, brand new VSS last week. No change.

The drivers side cat is confirmed hollow as of today. The passangers side is suspect clogged but it is not hollow.

There is absolutly ZERO coolant loss. I monitored it closly for the past 1500 miles, no change.

Autologic testbook found only rear o2 sensors switching at over 400 while front in the mid 100's. I was told rear O2's are shot. They plug into the ecu, There doing something guys. It goes to show that not all of you are gems literate. If you dont have positive input, keep it to yourself.

This is a 5-speed truck. Dont offer up the 3rd gear shit. It does not apply.

The computer might still be fudged. I have not explored this possibility.

Since this thing goes hooey after it warms up, somthign is getting warm and screwing up or the computer is entering drive cycle a and thats where it screws up.

Also, the autologic sees many more codes than the acctron OBD II reader. I can only discredit Land Rover for making this truck not truly OBD II compliant. And i'm taking about generic codes, not P codes.

If there is a bad sensor, the GEMS shitbox cant pinpoint it.

I confirmed today that the motor has good vaccum and is not suffering any timing or lifter problems. Also, compression is good as the needle is a rock steady 18 inches of vacuum at idle no matter hot or cold. Does not fall seadily afer running at 2000 rpm stable either.

I will obtain a good set of cats and sensors and report back. The truck is now drivable with the left rear 02 sensor disconnected.

 

[Craigness]

in addition.....

As far as the chevy thing goes...

If GMC made a truck that could compare with a land rover is offroad prowess and size I would buy it and never look back. I love my rovers for what I want them to do when I need them to do it. I loved my GMC/Chevy's for ALLWAYS being there for me and NEVER EVER stranding me. EVER. I have put over 600,000 miles on GM trucks with almost no michanical problems. My last 1995 Tahoe I sold for 7G with 200k on the clock. It never failed me ever. It now has 235k on it and belongs to a buddy of mine.

I sold my 97 Yukon SLT with 145k on it running as new. NEVER saw a check engine light or valve tick. NEVER LEAKED. In fact, no GM truck I have owned ever leaked.

So who as the name of the guy with the 350 adapter rings?

 

[sven]

Autologic testbook found only rear o2 sensors switching at over 400 while front in the mid 100's. I was told rear O2's are shot. They plug into the ecu, There doing something guys. It goes to show that not all of you are gems literate. If you dont have positive input, keep it to yourself.

Actually.....we are GEMS literate. The pre-O2s adjust the mixture, the rears are for monitoring the effectiveness of the cats. You will get a rear o2 failure if the cat is clogged, no doubt. (This is all read from the RAVE cd, BTW) I suggest that you hollow the suspect cat (since the other one is hollowed) to further diagnos the problem. Its free , just not legal.

The other thing maybe that the front 02 wires are crossed. The RAVE cd explains that if the front o2 wires are switched, one side will run rich while the other runs lean, causing all sorts of misfire and rich/lean codes. This can also cause the cats to clog. If you have the RAVE cd, check that all your wires are going to the proper o2 sensor.

http://www.marks4wd.com/ sells the 350 conversion kit...good luck with that one..

 

[Chris-St Louis]

I sure wish I knew more about GEMS!

 

[Craigness]

update...

Well, I did some experimenting....

If I do remove a rear o2 sensor, the hesitation goes away but the truck will not get past 70mph on the flats and 55mph uphill. I suspect it's in some sort of limp home mode but it's been 3 days like this and no CEL. I replaced the rear o2 sensor with a new one (left side) and the truck started to act up again after 10 minutes. Also, I confirmed the drivers side (Left again) is hollow.

The following is now fact:

The rear o2 sensors DO affect the computers adaptive values and engine managment pertaining to drivability. They DO NOT just monitor emissions.

A new O2 sensor on the misfire side is NOT resolving the issue.

Questions: Will a hollow cat create a situation that would create a misfire and hesitation? I suspect it's a "Lean Misfire" as there is a burning sensation on my eyes from the exhaust and there is no smoke of any kind other than some white smoke (Condensation) for the first 10 minutes from cold.

On the autologic computer the rear O2 sensors were showing values in teh 400's and the fron around 150-180's. The michanic told me that the rear 02's were fried. Does this sound correct?

Anyone?