Thread: Raising boost on a td5

2003 D2, I have been reading threads on boosting the turbo, I have made a few turns (to the point it cut out) on the wastegate arm and have backed off a turn or two. I recently removed the mid muffler and fit the EGR removal kit (which made significant improvements), but adjusting the turbo seems to be making no difference at all, if anything a tiny bit better at low revs, but losing a lot a higher revs - almost gutless ?


Is this common ? I am thinking the best way forward will be to buy a boost gauge where I can adjust and monitor ?


Is there anything I am doing wrong or are there any better ideas how to go about it ? I do not have access to a nanocom at present.

Hi, unplug the MAF and test drive it that way too, increased boost means higher suction too and if the MAF reading exceeds 680 the management will reduce fueling, IMO simply tightening the wastegate actuator without a remap and without the certainity that all the sensors are working well is not the best way to do things, did you clean the MAP/IAT sensor after EGR bypass? you said you removed the middle silencer but do you have a de-cat downpipe too?, cos that's more important than the middle pipe, also the depression controll valve should be replaced if it's old, ... and so on... there are too many elements involved which must be monitored so you really need a nanocom for a proper diagnose.

Many thanks, I did give the MAF sensor a bit of a clean when I removed the EGR, screwdriver in a rag which I am thinking now might not have been the best way to have done it ? So best way now will be to disconnect MAF and see if any difference.

I should add I am planning on a TD5 inside remap once the budget permits. Will get back to you. Cheers Matt.

so I disconnected the MAF this morning, and electrical connection had evidence of liquid on it, not quite sure what liquid. Did a 20 minute run and ran very slightly better, but no more 'go' from the engine. I will take some a couple of photos later as there is some oil in the area, maybe this might have something to do with it. Guessing the ultimate plan has to be to get connected to a Nanocom for some accurate data and can also set the boost correctly.

I was asking if you cleaned the MAP/IAT(the one in the inlet manifold) after EGR removal cos that one gets loaded of muck ... if with MAF unplugged is slightly better or even the same it means the MAF doesnt work as it should, check fuse F2 in engine bay just to rule it out

Thanks Sierrafery, doing more research this morning, I only unplugged the MAP sensor before work today. I did nothing to the MAF sensor. So what is best steps to go from here ? Re-connect the MAP and disconnect the MAF ? I did clean the MAP when I fitted the EGR, but with some soft cloth and no chemicals, guessing I have probably hashed this up and am going to buy some contact cleaner from Jaycar tomorrow. Am I doing this right to find out what might be wrong?


I have also contact the guy I bought the car from 2 years back and he has said I can go over and try his nanocom this weekend. Not sure if it is the right type of nanocom firstly and whilst he is obviously a very talented mechanic, not sure how technical he can be on TD5's. Sorry to be making this a long post, but what are the basics I should be doing with the nanocom ? Thanks again. Matt.

With the nanocom you can see what reading the MAF is giving out. Idle is 50-60 and you can see it go up from there. MAP will be shown in bar just so you know.

The issue is when you turn up the boost, you can easily go over the allowed 680 on your MAF. That is the point I am at and trying to figure a way around. I would prefer to not block the signal and limit the MAF to 650 as the ECU will then just fuel for that ratio, which of course it will actually be higher. I don't get the MIL light and fuel cut off, I just get reading of zero and default mapping.

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