Thread: Low power... Grrr...

Hey Gav - sure is.

From the main menu - select LIVE VALUES then ENGINE BCU and BOOST is in the list 4th or 5th

Gav
If your sure it's not fuel or the boost control valve; look for a stuck open wastegate valve (was this replaced ?) or the MAF sensor ?

Laurie

Thanks, entire turbo is brand new, not rebuilt so that counts out anything being stuck. Didn't think about the MAF though. I'm not sure it's not the boost control valve - are you talking about the bit in the engine bay that has a sensor on it? No idea how to test that though...

I'll report back later today...

Cheers.

Gav,

there have been people with the TD5's being down on power and found after cleaning or replacing the MAF had a great improvement. Not sure where it is on your engine though but will be somewhere on the air intake. Give it a spray with MAF or contact cleaner and see how it goes.

Cheers,
Dave.

On my track car, an Rx7 13B Turbo, I had leaks but couldn't find them. So I sealed the front of the turbo with very thick plastic so it formed a kind of lid, then pocked a hole in the centre of the plastic with the end of the compressor. Ended up pumping 40PSI in to it and found two leaks I didn't find prior.. Both fixed that night - then happy days...

Well, finally got back to it today - I've been putting it off with more fun things like camping and working on a friends series II...

Pulled and cleaned the MAF - it was quite dirty, but that didn't fix it. Went back over all the boost pipes again - everything fine. I was then looking on line and there was a mention that the Garrett VNT turbos won't provide boost if the vacuum is weak to the modulator. When I tested this - engine running, tongue on vacuum line I found exactly zero vacuum...

I had checked these lines visually before and didn't see anything wrong, but I pulled them off - the long one from the vacuum manifold on the LHS of the engine, and the short one between the vacuum accumulator and the boost control valve, I found both to be leaking. The pic below shows this clearly but they weren't quite as obvious when I first pulled them off - I've opened them up quite a bit flexing them as I checked them.

So, new vac line on and went for a spin - low power is not something I can complain about now - it goes like the clappers....

I think a combination of vacuum leaks and a shagged turbo has crept up slowly on us so we really didn't notice how low on power it was. It bloody flys now...

I also found the other small vac lines to be in poor shape so I'll replace them all before it goes back on the road, but I only had enough today to the turbo lines.

SWMBO will be happy when she gets home...

That's great news Gav and a cheap fix if not for the time spent b I would have thought those lines would have been replaced when the turbo was done ?
I know what you mean when you said the performance drop off over time wasn't noticed. It's good to drive a comparable vehicle every now and then just to compare or have someone drive yours !

Laurie

I replaced the turbo myself, so there's only one person to blame for not doing the vac lines at the same time...