Hi all. My Disco '95 has very little power, driving terribly and struggling to make it up any hill, and maxing out on flat road at 30-40mph.This began after a shop replaced the injectors, distributor and ignition coil for issues with starting(they had no idea what they were doing).

After getting it back I worked with under the supervision of an expert land rover mechanic finding no compression in two of the cylinders. We figured this was the problem and proceed to do an entire rebuild of the top half of the engine, replacing the timing chain, re seating the valves, honing the cylinders. The car now has good compression but still runs the same as before. We tested the injectors and they all seem to work fine. The vacuum on the car is mis arranged, and I have not been able to find clear information regarding the proper arrangement anywhere. I am having a very hard time figuring out what is wrong. I managed to hook up the Rover Gauge, but do not know what to make of the results. I am curious if this shows the engine running rich or any other thoughts people have. Attached is a video of me taking the car on a short drive, including driving up a small hill. When accelerating I mainly have the gas to the floor. I have not worked on the car for quite some time but really want to try to get it back to being roadworthy. Any thoughts would be greatly appreciated! Thank you.



I've added a still image of the gauge reading for those who do not want to open the video file, this snapshot shows the car accelerating while going up a small hill.

 

I have a 3.9L (1994). Let's get the vacuum lines straightened out. Your set up looks a bit different than mine. Your hose to the distributor looks fine. There is an extra T in the PCV tube, going to the back. Is that what you are using to supply vacuum to the fuel pressure regulator? The small port on the L valve cover goes to the air filter box on mine. It supplies fresh air to sweep the crankcase.

Next thing to check is the ignition timing. Not easy to aim a timing light down there, but I know it can be done.

 

Isn’t the distributor vacuum line going to the wrong side of the advance port? So it would be retarding under vacuum load?

Also - a long shot but a few years ago I got a new distributor that had the wrong reluctor ring from a 6 cylinder… Made it run terribly obviously.

The 14CUX isn’t the most sophisticated. Yours seems to be trying to overfuel because the oxygen Is reading lean (I think).

 

Good eye, 94Disco1! Definitely on the wrong side of the distributor vacuum advance unit. Will not advance, so will be short on power.

If you check the reluctor ring, be sure to measure the gap while you are in there. Do not pull up on the rotor unless the shaft is being held down with a screwdriver or such. Otherwise the springs for the centrifugal weights can pop off, causing more work inside the distributor. If the springs pop off, that also can cause low power/torque.