MAF issues?

[coops71]

I've posted a few days ago regarding an on/off throttle issue while using light accelerator to maintain 40/50kmh on slight downhill situations. It's like the engine cuts on/off. Pretty annoying and embarrassing. Problem goes away when MAF sensor is disconnected. The MAF sensor reads stable and smooth on the nanocom. Reads 62 at idle and 600+ uphill wide open. Is it possible to have a bad MAF sensor which reads good on the nanocom, or might disconnecting it be masking other problems? It's a TD5 with egr blanked, TRS fuel map.

[Disco Muppet]

Is it a sort of...hiccup almost?
Short drop in revs and power?
Does it still happen with cruise control on?
If so, I had the exact same thing.
Some investigating pointed to the TPS, but it stopped doing it and hasn't since.

EDIT with mine, it didn't do it with CC on, hence pointing to the TPS

[coops71]

Is it a sort of...hiccup almost?
Short drop in revs and power?
Does it still happen with cruise control on?
If so, I had the exact same thing.
Some investigating pointed to the TPS, but it stopped doing it and hasn't since.

EDIT with mine, it didn't do it with CC on, hence pointing to the TPS

It's not the TPS as it still does it on cruise. Drops from 1500rpm to idle, on/off.

[Disco Muppet]

It's not the TPS as it still does it on cruise. Drops from 1500rpm to idle, on/off.

Wow, sounds like a restriction of airflow alright.
Checked things like fuel lines, stuff like that?
I suppose it's possible a faulty MAF could read fine on a Nanocom

[OffTrack]

I suppose it's possible a faulty MAF could read fine on a Nanocom


Nanocom reads the values that the ECM is getting from the sensors. If the values are with in range and you aren't seeing spikes/glitches while recording fuelling inputs then the ECM is getting steady information from the MAF, and is highly unlikely to be causing this issue.

If you want to eliminate the MAF record the fuelling inputs while trying to replicate the problem.


I had a stock map loaded on my D2 last week and I was shocked at just how much more civilised the car was. I have a davis rechipped ECU in mine and it is uncouth in comparison. I was seriously tempted to stay with the stock map tbh.

[coops71]

Problem has returned with MAF disconnected, but nowhere near as bad. Seems to be much more of an issue when the car is cold. Only started happenning after fuel filter change and new fuel pressure reg. Manifold turbo pressure is smooth. Small amount of oil in loom. have ordered new one last week. Hope this might be the issue. Bugger!

[jakeslouw]

Check fuel pressure sensor and fuel temp sensors if fitted.