Thread: 94 300tdi low on power

If you want to rev past 4000rpm you have bought the wrong car, try turning the diaphram under the torx screw to increase the fuel.

Originally Posted by redrovertdi

If you want to rev past 4000rpm you have bought the wrong car, try turning the diaphram under the torx screw to increase the fuel.

I have only gone over 4k rpm a couple of times and as RRtdi said there aint much left after 4k rpm, but you shouldnt need to ring it out either.
Check your intercooler hoses for delamination and also the valve clearances for starters.

Ok, maybe I need to clarify what I said. It seems to labour all the way through the RPM range, upt to 4k RPM. The main point I'm trying to get across is that it is lacking compared to another I have test driven, by a decent margin!

I'll check out valve clearances over the weekend first. Do you think they would impact the power torx screw not having an effect? After that, I'll give the diaphragm a fiddle and hope something happens there.

Also, when you say delamination, what exactly am I looking for? (ie what is delamination!)

why'd you buy it if it felt low on power compared to others you have driven?

Originally Posted by xaymaca

... .... ...
Also, when you say delamination, what exactly am I looking for? (ie what is delamination!)

The layers of rubber and fabric that make up the turbo hoses can separate. If the inside layer is coming loose, a flap of that layer can block the air flow through the hose. If that happens, the turbo boost can be reduced.

Does the 90 degree elbow hose feel unusually soft?

I bought it because it was very cheap considering the rest of the car is quite good, and the rest of the mechanicals are good. It was one of those times where the offer was good.
I figured even if I have to redo the head gasket or replace injector pump I'll still be in front, but aiming for quick wins first.

The elbow does seem pretty ratty and soft, maybe I'll look to replace all with silicone jobs.

is it blowing black smoke when you bury the boot?

if it is its not getting enough air.

is it blowing white smoke or making ugly knocking noises?

if it is the timings out.

if its not blowing black smoke its not getting enough fuel.

if its not blowing black smoke and you can hear a faint whistle on deceleration you've blown the compensator hose.

Ok, so while that post was really simple, it seemed to help me a lot.

I went home, got the wife to watch me accelerate down the road. She said there was a tiny puff of white smoke for a second, then no smoke after that all the way through the gear.

So I went back home, and did as suggested and turned the diaphragm about 90degress clockwise (not brave to go more than that as I'm still waiting on EGT gauge to arrive!). That seemed to have helped overall. I then turned the torx screw another .5 CW and maybe a bit of black smoke on starting the engine now.

This seems to have helped (still not great), however I'm going to leave it where it is until my gauge arrives just to be safe.

Thanks for your help everyone, I'll report back!