Offroad-Express

So, I've been playing around with my terrano.

I've never worked with a diesel engine before, or a turbo to be honest so sorry if there's some stupid questions ahead.

first, after speaking to a friendly mechanic I located and adjusted the fuel screw by 1/4 turn.
what a difference! Soo much quicker off the mark.

then

I took off the inlet manifold cleaned out all the gunk, removed the overboost valve and bung'd the hole.
I have also blocked off the egr, I left everything in place just put a steel plate on the intake side and removed the butterfly in the intake.
this made not so much difference. In fact nothing that I could notice.

should I expect an increase in power or would I only find this if there was something going wrong with these components before removal?

Also, having someone hit the gas while watching the waste gate actuator should it open before getting to full revs? as there was no movement from mine anywhere in the rev range,

and what I really need to know is. If my waste gate is not working properly and I have removed the overboost valve and wound up the fuel is my engine going to loose it's shit?

I know I really need to get a boost guage and EGT Guage so I can keep an eye on things but I'm not really a fan of extra gages everywhere so if it's possible to set it up so I can be confident it's not going to cook or pop would be good.

thanks for any advice or input.

Your not a fan of extra gauges?
So your not a fan of reliably monitoring your engine? Because that's the only way you can be sure of what your engine is doing..

Yeah that probably came across wrong. I'm looking for some guages at the moment. I mean I'm not keen on guages all over my dash. trying to find a way of keeping it looking tidy. can they be mounted in the altimeter pod on the dash? I'd just like to know if the engine is safe until I get these mounted.

I have an EGT and Boost gauge going spare. I recently replaced them with digital ones. They should fit into your pod. I will post details tonight.

there are three possible reasons for the waste gate actuator not to open.
1. it may not have its hose connected to a boost source(unlikely, but check)
2. the waste gate actuator or the waste gate hinge could be jammed.(unlikely, but) very easy to check. Pull the waste gate actuator hose off and blow compressed air into hose. The compressed air will move the actuator arm, unless something is faulty.
3. The engine requires 'load' for it to come onto boost. Often(normally), a turbo motor will not make any boost if you are just revving it in neutral or park. So the manifold sees no boost, so the waste gate actuator hose didn't receive any boost pressure which it uses to open the waste gate.
This third scenario is by far the most likely, but worth checking the other two just to eliminate them.

FYI the only times a motor will make positive boost when free revved, is if the turbo is too small for the size of the motor, or if the ignition is hugely retarded(which causes massive heat in the exhaust manifold, hence spooling the turbo up)

IT wont go pop. but get a pyro gauge in there as cranking up the fuel will cause excessive heat if your on the gas pedal too much without letting the engine breath properly.

on a engine that age the boost will overcome the waste gate spring anyway so will still only hit about 14-18 psi .

The turbo wont handle much more then that anyway But the actual engine (block/head) will take a hiding.

yep free revving a td27 will only get you a couple of psi.

Only real differecne I noticed when removing egr on my old terrano was a little more mid range grunt and boost came in ealier (egr valve wasn't closing properly) and (although mine was an auto) way less of a smoke puff when getting back on the gas after coasting.

Good to know. Thanks
I will get some gauges in there before I take it out and thrash it again, but can feel confident that day to day driving won't do any damage.
need to get a catch tank sorted too I couldn't believe the amount of crap in the intake.

For4byfour wrote:Good to know. Thanks
I will get some gauges in there before I take it out and thrash it again, but can feel confident that day to day driving won't do any damage.
need to get a catch tank sorted too I couldn't believe the amount of crap in the intake.

that's the carbon from the egr not so much the oily crank case ventilation. If it was just oil it would be oily but not filled with a tar like substance.