1997 Disco I automatic tranny. About three weeks ago, I pulled up to a stop light, (at operating temerature and running for a few miles) and the engine dropped down to about 400 rpm for a couple of seconds like the engine was going to die, then jumped back up to normal. Since then, it seems to do this once every time I drive it, not every time though.....Yesterday, it was hard to start for the first time, and after starting, it barely ran for a few seconds, then suddenly the rpms came up to normal and it ran like normal. What is going on?

Thanks for any help!

 

Sorry, forgot to mention it has 106k miles.

 

try checking the connections to all of your sensors, example: iac, 02, tps, maf, map, etc

 

also may want to check the vss sensor possibly. is it throwing any codes/lights etc.?

 

Everything seems to be connected. The only code that is popping up is for the ABS system....I've had the system disconnected since I've owned the vehicle, as it was malfunctioning, so I pulled the fuse and just don't have ABS. No new codes though.

What about the fuel system? Do rovers have any common problems that pop up?

 

2 things:

Your MAF needs cleaning. (do you have a K&N air filter?)

Sounds like the idle air valve (or "stepper motor"), located on the front of the intake plenum about midway. Remove and clean often fixes it.

 

It could be the fuel temperature sensor if this is going out it will
not let the ECM know how much fuel to use.
Some of the affects are bad idle, hard starting.
Its on the fuel rail.
I don't know how to see if its still good.
lol Mike

 

Sounds like stepper motor. Unless your speed-o is doing weird things too. Then, it might be a VSS...I still bet stepper motor, like Mike said.

 

I checked my workshop manual last night and if any sensor on the fuel sys
was going out it would set the MIL light.
Is the truck doing anything else?

 

that exact thing just happened to one of my discos...changed the throttle position sensor and it was fixed