td5 defender power issue

can any body help. 110 td5 started to lose power after about 15mins driveing, if i restart engine seems to correct itself then happens again several miles later. waste gate free and recent new airflow sensor.when power goes its almost like limp mode barely get to 35mph. any advice appreciated.

Injector seals and fuel pump

Both fair Suspects

Cheers

Discodevon said:

Injector seals and fuel pump

Both fair Suspects

Cheers

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thanks for reply, will that show up on plug in fault finder?

pinuser1 said:

thanks for reply, will that show up on plug in fault finder?

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If you haven't used a genuine maf sensor that could be it, the after market ones are dog poo

Unplug the maf and see if things improve. If so there is your answer.

thanks fellas for input, travelled 30 miles today running fine,on return journey going well then suddenly a noticiable lack of power again struggling to make 40mph, pulled up at lights and turned off engine restarted and running fine all the way home.. if it was maf wouldnt it be flat all the time.. it seems to correct itself on restart of ignition. wheras in the past when maf was not working was just lifeless all the time..wondering if i should just buy a seimens new sensor and fit it, before going down garages plug in and cost a fourtune route. any info appreciated

Could be a stupid idea but, is your fuel tank venting properly?
Had similar on my sons vw polo, tank breather was blocked, don't know how Td5s work.

Shifty1962 said:

Unplug the maf and see if things improve. If so there is your answer.

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thanks ,would it work by unpluging the maf when engine is running when this lack of power kicks in, as if i turn off ignition it will be ok again for a while//

pinuser1 said:

thanks ,would it work by unpluging the maf when engine is running when this lack of power kicks in, as if i turn off ignition it will be ok again for a while//

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Yes you could do that. The ECU will quickly decide the MAF signal is not present and switch to a default mapping with preset MAF values. If the power output picks up then the culprit is the MAF sending unreliable signals but as there is a varying signal present the ECU will not switch to default mode. Of course it could also be a dodgy MAF connector or wiring causing intermittent issues and the MAF may be perfectly OK.

Oddly enough, i had a similar issue in my 90. Lost power, then came back as if it was limp mode but no lights

Turned out to be a failing crank sensor.

Shifty1962 said:

Yes you could do that. The ECU will quickly decide the MAF signal is not present and switch to a default mapping with preset MAF values. If the power output picks up then the culprit is the MAF sending unreliable signals but as there is a varying signal present the ECU will not switch to default mode. Of course it could also be a dodgy MAF connector or wiring causing intermittent issues and the MAF may be perfectly OK.

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makes a lot of sense what you say will give that a crack. thanks for input