Help: Absoulty Dumbfounded....Been working on this for a while!

[montego]

Ok guys, any imput on this subject would be greatly appreciated. I will give you as much info as I can, but if you ahve anymore questions to try and pin point the problem please let me know. BTW this is a D1. Here we go.

I was driving to work on day, and the car down shifted on the interstate. All the sudden the rover would not rev over 3500 rpms. I thought this was a really wierd because it would rev smooth all the way up to 3500 then BLAP BLAP BLAP BLAP!!! It would just rev out. I limped to work and let it sit. After word I got in the truck to see what would happen. I drove home fine, and I couldn't repeat the issue on the way home.

About two weeks later it starts again when I was cruising down the road. Starts again at 3500 rpms. Then when I am limping home it drops to 2500 then 1500 and now at about 1300 rpms!!!!!

So now it will not rev over 1300 rpms. When it gets there all you get is blap blap pop brrrr blap balp!!!!

Soooooooo.......
I originally I thought that maybe the fuel filter was clogged and the truck was choked for fuel. Changed it and no process.

I was a bit stumped at this point and didnt have much time to tinker with it so I brought it to Land Rover New Olreans for them to diagnose it (not to fix it). they told me that the cats were clogged and they needed to be changed because they were causing to much back pressure. Ok, that is beleiveable, but I wanted to make sure this was right because LR wants 2g's for cats.

I tow it back home and drop the cats.... Start the truck and NOTHING. Still wont pass 1300 rpms. I start thinking about other things now.

I pull all the plugs and make sure none of them or steam cleaned. All of them are good and only 3 months old. I regap them just to make sure. I also made sure I was getting spark from all of them.

Then I did a compression test. The results are as follows...

1) 145 2) 151
3) 143 4) 150
5) 140 6) 149
7) 141 8) 140

Thats pretty good IMO. So I doubt it is anyhting to do with that. Plus I have no leaks from my head gaskets.

So now at this point I am really confused I really dont know what it could be. The only thing I can think of now is electronic.

Any thoughts fellas? has anyone else had anything like this happen?

thanks,
-josh

[Disco Mike]

What year is your truck?
Any check engine lights on?
Have you checked the fuel pressure while this is happening and after it sits for awhile?
Mike

[montego]

Sorry,
the truck is a 96 disco1.
No check engine light.
No I have not checked the fuel pressure. Is there a thread on here that would show me where to check the pressure? I.E. Where do I tap the line to check the pressure?

[discohunter]

this sounds a bit like what mine was doing when the fuel pump was going out. sputtering, surging, lack of power at all. I put in a used fuel pump and it fixed the problem. FP is an easy do it yourself replacement too.

[DaveC]

I've heard of these problems being the VSS or vehicle speed sensor. It's located between the transfer case and parking brake drum I believe. I've never had mine apart, but I know that people take them off, clean and re-install with a sealant to prevent water from getting in. Also put some dielectric grease on the connector plug. A search on here or discoweb will give a better description with diagrams. To check the VSS, people unplug it and drive. You will have no speedometer, but nothing else should be effected. I've unplugged mine and driven without problems.

Just an idea. Dave

[montego]

Dave,

I have never checked this, but does this kick in only when the car is moving, because mine wont rev past 1300 rpms even if it is sitting in my garage (which it has been with the cats off. I think I am going deaf)

[DaveC]

oh, sorry missed that part. This isn't your problem then. GEMS motors have a lot of sensors. I hope it's something simple.



Dave

[Kevin88RRC]

Might be a long shot, but check your air intake. I had the hose collapse inside cutting off almost all the air. So it would idle fine, but try to do anything & nada.

[montego]

hey guys! I have been searching and I found that most peeps have been having some of the same issues because of the knock sensor, and I would like to check it. The only problem is that I am not sure where to look lok, or even what I am looking for. Could someone point me in the right direction????

thanks,
-josh

[montego]

whoooooHoooooo!!!
Ok guys, so I found the knock sensor, and sook it off. The heat shield was absoutly distroyed, and the sensor was a little dirty(no supprise), but the big deal was the wire. The wire was completly melted through!!! The interiors was al exposed and melted to the block. I took it off and fixed the wire with heat shrink. I cleaned up the sensor and stuck it back in. When I turned the key....blammo!!! It started right up and ran all day today like a champ.

thanks for all the help fellas!1

-josh

[pavel]

So where is the knock sensor?

[montego]

It is on the driver side of the tranny. On the front of the bell housing, across from the starter. It has a little heat shield thing that covers it, but mine was pretty much gone. Just two 7mm bolts hold it in.
-josh

[pavel]

Thank you Josh - as soon as it stops raining, I'll check ours out. Cheers.

[96discose7]

Originally Posted by montego

whoooooHoooooo!!!
Ok guys, so I found the knock sensor, and sook it off. The heat shield was absoutly distroyed, and the sensor was a little dirty(no supprise), but the big deal was the wire. The wire was completly melted through!!! The interiors was al exposed and melted to the block. I took it off and fixed the wire with heat shrink. I cleaned up the sensor and stuck it back in. When I turned the key....blammo!!! It started right up and ran all day today like a champ.

thanks for all the help fellas!1

-josh

HEY you know who told you how to fix this....... dont try to take all the credit..... plus it is the CRANK POSITION SENSOR that is the culprit, well acutally the wires to it..... just wanna help others -Andy