MAF sensor

rogerball0

UK Spec 2002 LWB 311 CDI
I can't find one in my engine bay, should be attached to the airbox from pictures i found online but theres nothing there, its a UK van so dunno if that has a bearing on things?
 

rogerball0

UK Spec 2002 LWB 311 CDI
Your model has no MAF. It probably has no egr either.
Cheers Midwest just trying to get to the bottom of the rough idle problem i still have, got told to check the MAF sensor. Didn't think it had one as the exhaust is straight through from the manifold with no electro-mechanical ****ery attached so was pretty sure it didn't.

The other thing i think i need to check is the harmonic balancer: from reading these very pages i get the impression - along with an old belt and pulleys - that that might be the cause and seeing as the belt needs changing wouldn't hurt to check that.

Am thinking of purchasing a clone C3 diagnostic kit to better get an idea of the faults as the van sounds rough and the icarsoft reader shows no DTC's. Had to get the poor girl towed home Friday as the left hand front wheel bearing gave out with no warning plus the operating temperature seems to be stuck on 55C instead of 80C so suspect a knackered thermostat.

If i do the belts and pulleys would it be advisable to change the water pump whilst the fronts off?
 

Midwestdrifter

Engineer In Residence
Water pumps are generally suggested every 100k miles or so. Though just pulleys and belt don't require taking the radiator off.

Rough idle on these engines tends to be one of two causes. Air infiltration (check for air bubbles in the clear fuel line section). Or bad injectors. Injectors can be removed and tested by a Bosch shop.

Sometimes the MAP sensor or intake air sensor can go wonky. That can be checked with a good scan tool.
 

rogerball0

UK Spec 2002 LWB 311 CDI
Water pumps are generally suggested every 100k miles or so. Though just pulleys and belt don't require taking the radiator off.

Rough idle on these engines tends to be one of two causes. Air infiltration (check for air bubbles in the clear fuel line section). Or bad injectors. Injectors can be removed and tested by a Bosch shop.

Sometimes the MAP sensor or intake air sensor can go wonky. That can be checked with a good scan tool.
Hi Mid west i was underneath the van yesterday and realised the fuel tap i'd put in for a heater i intend fitting in the back had fuel in it although nothing is connected up its just coiled up with the end (i thought) sealed up but i could see diesel had leaked from this pipe & had taken some of the waxoil off the chassis so i'm wondering if that might be enough to contribute to the rough idle problem i still have?
 

Cheyenne

UK 2004 T1N 313CDi
Hi Mid west i was underneath the van yesterday and realised the fuel tap i'd put in for a heater i intend fitting in the back had fuel in it although nothing is connected up its just coiled up with the end (i thought) sealed up but i could see diesel had leaked from this pipe & had taken some of the waxoil off the chassis so i'm wondering if that might be enough to contribute to the rough idle problem i still have?
Roger,

Is this fuel tap 'T'd into the existing engine fuel lines or drilled into the tank?

If it is 'T'd into the existing lines than you could be sucking air in through it and causing your issues. Can you plug it effectively as a test?

Keith.
 

rogerball0

UK Spec 2002 LWB 311 CDI
Roger,

Is this fuel tap 'T'd into the existing engine fuel lines or drilled into the tank?

If it is 'T'd into the existing lines than you could be sucking air in through it and causing your issues. Can you plug it effectively as a test?

Keith.
Hi Keith

No it was a webasto aftermarket jobby i fitted into the tank fitted the heaters pipe work to it and left it coiled up in the chassis. I plugged the end with a small gauge screw to block the pipe more effectively. I had totally forgotten about it, bit embarassed really. Would be ace if that was what was causing the problem, plus i'm leaning more towards it being a fuel issue causing the problem rather than injectors as i had a good deal of the fuel system apart / off the van when doing the chassis work in October so may drop the tank back down and have a look when i get a bit of time.

Heres a pic of the mod to the tank:

https://photos.app.goo.gl/x7PBgfYzyox219Ag9

Cheers
 
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Cheyenne

UK 2004 T1N 313CDi
Hi Roger,

Cheers for the update, as you have now found out screws don't work to plug hoses! The Diesel will migrate up the screw threads and eventually leak.

You need either a screw with a plain shank or a piece of plain rod, something like the shank of a twist drill works well!

Keith.
 

rogerball0

UK Spec 2002 LWB 311 CDI
Hi Roger,

Cheers for the update, as you have now found out screws don't work to plug hoses! The Diesel will migrate up the screw threads and eventually leak.

You need either a screw with a plain shank or a piece of plain rod, something like the shank of a twist drill works well!

Keith.
Never thought of that, what a great idea! I shall fit a HSS drill bit into the hose tomorrow and report back.

Cheers Keith
 

grumpy-old-van

A little bit Oooh Errrr
Yeah I was struggling to work out why no MAF on mine too
These ones are a "speed density" injection system, its more rugged and less prone to fail by all accounts but does mean computer gets no feedback on the amount of fuel in the cylinders..it just fires the injectors for a set time and assumes they work
this was the reason for my rough idle, 2 cyinders were adding extra fuel

You likely wont have the MAF, EGR as mentioned, also O2 sensor and Catalytic convertor which, makes the exhaust cheap to replace : )
 
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rogerball0

UK Spec 2002 LWB 311 CDI
Yeah I was struggling to work out why no MAF on mine too
These ones are a "speed density" injection system, its more rugged and less prone to fail by all accounts but does mean computer gets no feedback on the amount of fuel in the cylinders..it just fires the injectors for a set time and assumes they work
this was the reason for my rough idle, 2 cyinders were adding extra fuel

You likely wont have the MAF, EGR as mentioned, also O2 sensor and Catalytic convertor which, makes the exhaust cheap to replace : )
Cheers GOV

Thats one of ticks in the 'keep van' column, the fact our vans have none of the electronic fukery the later models have, my exhaust from manifold to the rear step cost £100 to replace, it came four sections instead of two but a small price to pay. I'm gonna look at the fuel tap i forgot about and plug it properly tomorrow and see what happens.

How did you sort your problem/ Did you remove the injectors and get them tested?
 

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