300tdi overboosting and high EGT

[redrovertdi]

In the last couple of weeks my 300tdi defender[full front intercooler and MTQ water cooled turbo and 3 inch exhaust and automatic] has been down on top end power with boost upto 25ish psi and egt's hitting 770ish whilst struggling to maintain 90km/h on a slight incline that was previously unnotticed, previously under full load i wouldnt hit 700egt at maximum boost of 22psi.
All silicon hoses checked and no holes or splits found.
Any ideas?

[Blknight.aus]

check your valve adjustments and timing pin the crank and injector pump.

you might have also had some exhaust damage thats restricting flow near the end of the pipe,

Are you hitting lockup on the auto and whats a stall test come out at?

Do you have any pump mods on?

[redrovertdi]

i replaced the timing belt[80,000ks on this engine] recently, this problem was there before and after, pump was tuned at MR a year or so ago.
Did tappets last week, car is good on the flat but has nothing when it comes to a hill[and friends tdis go past]
auto locks up at 78ks according to gps

[Judo]

A random thought if the basics have been check and looking for something more obscure - the boost compensator acting up / diaphragm issue?

[Dougal]

Sounds like retarded timing. I wonder if the timing advance via case pressure on the pump is working?

[Jode]

Sounds like retarded timing. I wonder if the timing advance via case pressure on the pump is working?
That's restrained by springs in the bottom of the pump IIRC. But it's unlikely for the springs to break - from what I've read, the Bosch pumps tend to go forever.

I'm sure it's already been checked but... how's the air cleaner looking?

[redrovertdi]

That's restrained by springs in the bottom of the pump IIRC. But it's unlikely for the springs to break - from what I've read, the Bosch pumps tend to go forever.

I'm sure it's already been checked but... how's the air cleaner looking?

K&N air cleaned washed and re-oiled last week end, hoses from waste gate to injection pump also checked

[Bazzle218]

My 2 cents worth, Change out your fuel filters, could be restricting flow. As an x digger fixing unimogs we would get the same symptoms on road runs, Filter change back on the road again.

[Dougal]

That's restrained by springs in the bottom of the pump IIRC. But it's unlikely for the springs to break - from what I've read, the Bosch pumps tend to go forever.

I'm sure it's already been checked but... how's the air cleaner looking?

VE pumps have a vane pump inside which generates case pressure and advances timing with rpm. As they get older the pump wears, pressure drops and timing advance is lost.

But that's a gradual thing. Rapid onset of retarded timing can be caused by things like dead lift pumps and partly blocked fuel filters. But wholly blocked filters will give you loss of power and low egt.

My work car went from new filter to blocked enough to cause issues in one incident. That incident was running out of diesel and sucking the crap that normally sits on the bottom of the tank. It is VP pump (electronic) but same problems apply. It was throwing up error codes that injection timing didn't match crank position sensors and made me start thinking it had jumped a timing chain tooth.
But new filters (again) and disconnecting the battery overnight fixed it.

[redrovertdi]

mines always knocked up on hills worse than others in 300tdis, now wondering about pump thats 460,000ks old and the only repair its had was the throttle spindle 80,000ks ago

[Dougal]

mines always knocked up on hills worse than others in 300tdis, now wondering about pump thats 460,000ks old and the only repair its had was the throttle spindle 80,000ks ago

The 300tdi I've acquired has well over 300,000km on it too. So it's a concern. Apparently there are ways to measure this internal pressure and also ways to externally adjust the regulator.

The VW Tdi guys have all the inside information (literally) on these pumps. Many are even using 300tdi pumps to convert VW tdi engines to mechanical injection.