Hi all

On a recent journey my FL2 began being 'glitchy' with the acceleration and started belching black sooty smoke.

The forums suggested the MAF and that disconnecting the MAF could improve the problem and help diagnose. This was great advice and I brought a new app enabled OBD2 reader which confirmed no reading on the MAF.

I brought a cheap (£25) replacement and that seemed fine but still no MAF reading and now the engine fault light coming (for the 1st time).

The forum suggested that a cheap MAF was not a good idea, so feeling bouyed that the MAF was the problem I sourced a more expensive one. As soon as it was fitted the engine light went off and I was getting good MAF traces on the reader. BUT.... the acceleration has gone back to being glitchy with lots of black smoke again!!

So, needing to drive to the N of Scotland Ive disconnected the new MAF and its at least driving ok with no smoke, but I need to find out the root cause as MOT is due.

Does anyone have ideas?

The reader is only showing one fault when the new MAF is connected and thats Glow plugs, but assume this would have no impact on this issue.

The only thing I think it could be would a wiring issue, so with either no MAF connected or the 'dodgy' MAF, its as if there is no reading, but with the good MAF there should be a reading which is being impacted by a wiring problem.

Thanks for your thoughts!

The MAF is all about air flow.

With no MAF, I presume the engine will assume no turbo asistance and therefore only allow what will burn in your 2.2L of engine - ie as if it were normally aspirated.

With a MAF working (and the ECU recognising this) it will go by the amount of air going through the MAF as to how much fuel it can pump in. It may also decide that it can open the EGR to let some burnt oxygenless air in.

So I'm thinking that you have a burst induction hose somewhere and some of the air going through the MAF is being lost - therefore the engine is not is a position to allow the EGR/fuel mix it is telling the injectors to allow in. Hence smoke and poor running.

I thought the ECU used a ‘presumptive’ figure, if no reading from the MAF?

Freddie17 said:

I thought the ECU used a ‘presumptive’ figure, if no reading from the MAF?

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on the fl1/td4 .. maf has to be totally disconnected, before the ecu default map will operate. [afaik]
no idea re fl2's ..

Check the turbo hose for splits, also the hose under the throttle body, also i am presuming that the air filter is in good condition

GrumpyGel said:

The MAF is all about air flow.

With no MAF, I presume the engine will assume no turbo asistance and therefore only allow what will burn in your 2.2L of engine - ie as if it were normally aspirated.

With a MAF working (and the ECU recognising this) it will go by the amount of air going through the MAF as to how much fuel it can pump in. It may also decide that it can open the EGR to let some burnt oxygenless air in.

So I'm thinking that you have a burst induction hose somewhere and some of the air going through the MAF is being lost - therefore the engine is not is a position to allow the EGR/fuel mix it is telling the injectors to allow in. Hence smoke and poor running.

Click to expand...

Thanks for the advice

Having stopped being lazy and using my eyes I immediately found the real root cause was indeed a split hose just at the front of the engine between the block and the radiator.

I assume these induction hoses are easily found on line.

Thanks for the swift responses. I appreciate it

Stuvv said:

Thanks for the advice

Having stopped being lazy and using my eyes I immediately found the real root cause was indeed a split hose just at the front of the engine between the block and the radiator.

I assume these induction hoses are easily found on line.

Thanks for the swift responses. I appreciate it

Click to expand...

Yep - get some silicone ones. They last longer.
I’d replace all of them myself. I know 1 is tricky on the F2, but not having an F2, I’m not sure which one it is
Think it’s the one to the turbo.