Good Day All,
I have a 1997 Disco 300 tdi automatic transmission that I imported from the UK to Canada. Basically, the problem is as follows:
While on a road trip I noticed a sudden drop off in power while on the highway. The tachometer never seemed to get beyond 2,000 rpm. Concurrent with that, I also noticed that I could no longer hear the turbo when going up hills or accelerating quickly. Naturally, I suspected the wastegate actuator arm and when I stopped to have a look at the engine, I noticed that the actuator arm would not move. I was able to wiggle it free and apply the only lubricant available to me at the time (WD40).
After I did this, I could hear the turbo engage while going up hills or accelerating quickly. However, there seemed to still be difficulty in achieving rpms in excess of 2,500. The next day the problem seemed to correct itself and I had full power.
Then after a couple of days, I noticed the problem again where the engine did not “want” to go beyond 2,000 rpm however I could still hear the turbo.
I took the vehicle to a diesel mechanic and he confirmed the functionality of the turbo by getting me to put the vehicle in Drive and revving the engine while applying the break.
When I open up the throttle (in any gear) the rpms go up smoothly (up until 2,000) and then the vehicle feels like it's being artificially starved of fuel. The engine will get to 2,000 and then I'll lose power; it'll get back to 2,000 and I'll lose power again. It's almost like the engine wants to go faster but something keeps preventing the increase in fuel going to the engine upon reaching 2,000rpm this me thinking ECU.
As I understand, when the vehicle "thinks" the wastegate actuator arm is jammed open, a similar fault occurs to prevent an excessive amount of air being forced into the engine.
To prevent damage to whatever mechanism seems to be artificially starving the engine of fuel by continuing this "engine starvation" process this, I kept the engine revving at just below 2,000. Of course when I encountered a hill, the transmission always wanted to shift down thus increasing my rpms and starving the engine until it got below 2,000 rpms. At a number of points in time I was going over hills at 18 km/h.
Interestingly, when I had sufficient momentum going downhill and began reaching speeds of 90-100 km/h, the rpms would be in the 2,000 region just from going downhill in top gear. Then I would again feel a stutter and some white (and a little bluish) smoke would come out of the tail pipe as if the engine was artificially being starved of fuel.
I've since replaced the turbo because, though the the old one was technically functioning, my mechanic noted that it was not providing sufficient pressure. However, there is still a problem with the engine being artificially starved of fuel leading to dodgy transmission shifting. My mechanic says the issue appears to be with the electronic adjusting of the injector pump. Mechanically the timing is fine. There is an error code that my mechanic's Bosch scanner comes up with that says "Start of Injection". We're both a bit puzzled by this.
Any ideas?
Norm
