Thread: Td5 losing power but not completely

Originally Posted by sierrafery

On first watch without even going into the data it's obvious that you have to replace the MAP/IAT sensor cos it's IAT side is fubar(120*C) and the engine runs like crap with that input cos the addaptive strategy for acceleration is mixed up. That's the main issue, the others are complementary for the symptom you described

I didn't notice that before - I was concentrating on the Cylinder 1 to 5 readings and correlating them with revs and road speed. A new MAP/IAT is ordered.

Thanks for that. All I really need now is to find some genuine and local injector seals and washers. I know the MAF is also FUBAR but I can run with that unplugged without screwing the drive-ability up too much. I'm still tempted to remove the air bleed valve and see how it goes....

The air bleed valve would cause starting issues first but you can drive without it without probs... i'd not touch the seals at this point if i was you

Originally Posted by sierrafery

The air bleed valve would cause starting issues first but you can drive without it without probs... i'd not touch the seals at this point if i was you

The reason I asked is that the symptoms are the same as when the air bleed valve was blocked a few thousand km's ago. When I cut that one open it was full of black gunk which would indicate the injector washers (or at least one of them) were leaking so I changed them then. At the moment I don't have a spare air bleed valve (one is ordered) and nor do I have a set of seals and washers so I can't change them... I'll give it a try without the air bleed valve tomorrow and report back.

Originally Posted by Markf

The reason I asked is that the symptoms are the same as when the air bleed valve was blocked a few thousand km's ago. When I cut that one open it was full of black gunk which would indicate the injector washers (or at least one of them) were leaking so I changed them then. At the moment I don't have a spare air bleed valve (one is ordered) and nor do I have a set of seals and washers so I can't change them... I'll give it a try without the air bleed valve tomorrow and report back.

Yes, when it's gunked up bad means that the copper washers were leaking combustion gas into the fuel return but in most cases it comes with hard starting as well, new copper washers should not leak so soon or if they were not replaced well the symptom should come sooner IMO... better wait untill you fit the new MAP sensor before you go for the washers again, the o-rings have nothing to do with this, if they are leaking you get fuel in the sump that's all.

OK today I removed the little plastic air bleed valve and gave the MAP/IAT a good clean. The air bleed valve (ABV) seems pretty black when you look at closely. The MAP/IAT was pretty grungy so I gave it a good spray with MAF cleaner and let it dry for a while before I put it back.
Anyway, here's the data from today's run plus a couple of pics of the ABV
To my way of thinking the only place the black gunk in the ABV could come from is a leaking injector washer so it looks like I'll have to get around to doing them again. Oh well, such is life in the D2 lane.. So until a new ABV arrives I'll continue to put up with hard starting and running without one.

I've had a quick look at the data and I'll need a new MAF sooner rather than later too. I also need to find the source of the boost leak and rectify that as well.

Seing that the IAT reading is restored i'd say that it was a bad contact in the plug or within the sensor cos the 120 reading is the default for open or short circuit, if it was about dirty sensor it should have read lower but still some normal(ish) values so keep watching that input.

Now that you've cleaned the map/iat it seems to be reading ok.

I can't tell you anything as regards the leak as your MAF is cactus, you could try cleaning it as well.

If that changes nothing, I'd unhook it, the car should go fine using the map sensor, and unhooking the MAF will stop fuelling switching between mass air and speed density (it'll be nicer to drive).

As regards the boost leak and dirty air bleed valve, they obviously need investigating.

Originally Posted by shack

Now that you've cleaned the map/iat it seems to be reading ok.

I can't tell you anything as regards the leak as your MAF is cactus, you could try cleaning it as well.

If that changes nothing, I'd unhook it, the car should go fine using the map sensor, and unhooking the MAF will stop fuelling switching between mass air and speed density (it'll be nicer to drive).

I've given the MAF a good clean. No change so I've just disconnected it and will run like that until I can afford a decent quality new one. I should have a new (genuine) MAP/IAT by tomorrow so I can eliminate that.

As regards the boost leak and dirty air bleed valve, they obviously need investigating.

I've changed all the boost hoses and a few weeks ago I changed the exhaust manifold gasket when it lost the first stud and started leaking. I also changed all the turbo and other exhaust gaskets at the time. I'm still trying to track down the leak but it's looking increasingly like the intercooler. Oh joy...
The grunge in the air bleed valve can only come from one place (I think) - leaking injector washers. I've ordered a new and genuine set which'll take a couple of weeks to get here. I'll run without the air bleed valve until I change the washers to save gunking up a new one.