Hi everybody!

I am a young enthusiast to Land Rovers. I recently purchased a 1994 Discovery 1 with 170,000miles. I've realized that these vehicles are not like any I've ever worked on!
When I purchased the vehicle I knew there was an issue with the lack of power. I thought that if i tuned up the vehicle it would fix the problem, so i have replaced and installed the following items:
- fuel pump
- fuel filter
- one O2 sensor
- spark plugs
- spark wires
- ignition pack
- timing chain
- oil pump
- oil pan gasket
- sump seal and gasket
- water pump gasket
- vacuum advance on distributor
- distributor button & Cap
(I have installed these items by help from the British Haynes Manual)

My issue is when I push down on the gas pedal there is little response and it takes forever to increase speed. I do not want to have to invest more money into this Rover. I haven't messed with the TPS yet and hope that it doesn't need replacing as well. Any ideas will help.

Thanks,
Garrett

 

You will also enjoy the RAVE, a collection of the factory shop, electrical, and owner's manuals. Free download below.

The TPS is of course a usual suspect. You could back probe the connector and measure 0-5 volts, you would expect to see a smooth operation. A bad TPS can cause lack of throttle response and failure to get much above 1800 rpm.

Would expect volt readings like these:

Voltage measured between the red wire (+ve ) and green (-ve).
Throttle closed .085 - .545 volts
Throttle wide open 4.2- 4.9 volts
The voltage swing between throttle open and throttle close should be smooth an linear.

For more info on the pre-GEMS systems, see Fuel injection

 

I have the Rave and found it to be very helpful!
I am able to rev the engine just fine when at idle. I start with 750rpm and can rev all the way to red line. Before i Breakout the meter to check, do you think it could be caused by any other reason?

 

Sounds like your kick down cable needs adjusting.
And after that remember that it had a whole whopping 182 horse power when brand new and now that it is old and tired...these are not quick trucks, they are not fast, they need to be driven like a semi, slow and in the right lane.

 

Thanks for all the advice. I'll take a look when i visit the garage next weekend. I'll post my findings and hopefully it can help the next person.

 

I also own a 94 and have done a lot of the same repairs. It is also very slow off the line. Considering the weight and gear ratios I think that might be all we can reasonably expect. I would like to drive/ride in another one just to see if there is a difference.

Also I don't believe the trans is very 'performance' oriented either. She shifts up to the next gear very quickly which is no doubt to help with emmisions and mileage. If the lower gears held longer, I think it would feel a little more spirited. I swear I'm in third gear before even getting across an intersection sometimes!

I will say that once the RPM's get above 3K it makes good noise and moves along smartly. It just takes a while to get out of the low rpm's. I occasionally have a slight stumble just off idle also so maybe I have TPS issues also.

 

Have you checked the timing?

To get a little more giddy-up, toss in a couple of degrees of advance to the base timing. Don't go crazy with it, but you may find 2 to (dare I say) 6* more of base timing will help out. Just be sure you don't induce preignition/detonation with too much.

 

Well I've checked into the problem and after a simple adjusting of the kickdown cable I've got better acceleration. I'll still test my TPS and make sure i'm getting the correct readings. The rave manual will be used for this task. For now the old Trooper is running and leak-free.

Thanks for all the advice.