Hello Forum Members,

I noticed that when it rains my Disco engine cannot accelerate anymore and limps at 1100 rpms. I pullover and let him stand, he can rev up.
From what I read on the posts, I suspect it is a problem with my wire harness.
Am I right? What else can be the problem?
Thank you for your input.

JC

 

There is a vehicle speed sensor on the back of transfer case. If truck is moving, that sensor can lie to the ECU, telling it that you are going 115 mph, at which point it starts cutting back the engine. When stopped you would have regular rpm as long as not moving. Test by unplugging sensor (you will loose speedometer and cruise).

You could also take a squirt bottle and mist the suspect wiring harnes or plug wires, or ther crank shaft position sensor cable and connector.

The ECU is in a box on the passenger firewall, sometimes those get wet and misbehave. Clean up and seal with silicone.

 

Any chance there is a big hole under the computer and water is splashing in?

 

Different symptoms, but I had three pins corroded on my ECU from water intrusion.

Any idiot-proof instructions on how to pull this off? I heard Lucky 8 had a sealed ECU solution that they stopped doing due to excessive heat issues (at least that's what my rover tech told me when he found the corroded contacts in my harness).

 

You either need a new throttle position sensor (TPS) or vehicle speed sensor (VSS). One of your sensors has gone bad. Most likely its the TPS.

 

TPS will show up on your scanner, starts at about 9%, then should go up smoothly.