Thread: Td5 losing power but not completely

Originally Posted by shack

I'd have another quick tweak..

In reality you possibly have a failing/leaking WGM, but adjusting it will negate that to some degree.

If I'm doing "high performance" tunes with a VGT, the WGM needs to be bang on.

It was a very quick tweak. But point taken. The WGM has always been a little sus I think.

Originally Posted by sierrafery

Without any tuning boost below 1.3 bar is low, that was the factory setting with wastegate at 13 threads and overboost limit at 1.42 . Running with low boost even if it seems OK it's not... especially if you dont have EGT gauge.

No EGT gauge on this car. Does the ECU limit overboost through fuelling?

Originally Posted by Tins

No EGT gauge on this car. Does the ECU limit overboost through fuelling?

No, but once you have hit an overboost situation, fuelling is reduced until an engine restart occurs.

Originally Posted by shack

No, but once you have hit an overboost situation, fuelling is reduced until an engine restart occurs.

Sorta what I meant, but that clears it up for me.

My 99's boost modulator failed open allowing unlimited boost. The ecm repeatedly temporarily cut fuel on hills due to the excessive boost.

Well, yesterday I replaced all of the boost hoses and the horrible hissing still occurs so I reckon that among other things I have a split intercooler...

The other thing that's suspect is the air bleed valve. I've had dramas with this in the past and the symptoms are similar. This leads me to a new question.

Can a Td5 run OK without the air bleed valve ? That is, just remove the plastic insert and run like that. I don't have a spare aid bleed valve so if I can run without it for a few days, until I can get a new one, that'd be good. If the air bleed valve is clogged that very firmly calls out the injector seals and washers. I s'pose I'd better order them (genuine of course) as I used my two sets last time I had dramas...

Originally Posted by Markf

Well, yesterday I replaced all of the boost hoses and the horrible hissing still occurs so I reckon that among other things I have a split intercooler...

If you post up or send me a recording log from the instruments screen on the nanocom, I can possibly tell you if you have a leak .... Only Possibly though as your MAF may be failing.

Originally Posted by shack

If you post up or send me a recording log from the instruments screen on the nanocom, I can possibly tell you if you have a leak .... Only Possibly though as your MAF may be failing.

I tried to get a recording yesterday but my SD card failed after it wrote a few lines... Bugger. I'll do it again today with another card.

I've got a leak alright - I can hear it at around 2300 rpm. It doesn't even have to be at much power. It's most notable at the change from 1st to 2nd and from 2nd to 3rd. It's an auto and I assume that 2300 rpm is around max boost depending on load.

Do you have any clues as to how it'd go with the air bleed valve removed ?