T4 bad idling and fuel use... please read!

[deadroo]

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Firstly hello, Ive just joined and just bought my first T4. 1993 2.5 petrol.
Ill summarise the issues im having and tell you what has been done to date. Any help so appreciated.

So. The van starts fine but within a minute revs drop and cuts out. (unless you feather the throttle) that is with vehicle stationary.
If i drive it is holding back and like its misfiring... if i dip the clutch it will clear under throttle.
It does this for a while and then runs abit smoother...
Also the temp gauge doesnt work... hasnt for ages apparently.
So with whats been changed below you can see the process they've gone through to attempt to fix it.
Today on idle i disconnected the temp sensor as the revs were dropping and it bought them back to a good balance.
If i disconnect while running the plug on throttle body i can rev it up freely but connected it struggles... and misses.
Maybe theres a few different problems and not one
I literally bought the van and did a 5 hour drive... (perth to denmark) It used sooo much fuel.

So looking at paper work its had abit done.
All within the last year and the vans only done 4000km since.

-New head
-Dizzy cap
-sparks
-temp sensor-(Its got invoices for 3 new sensors in past year!)
-fuel filter
-vacuum pipes changed (no leaks)
-second hand injector rail
-Timing belt
-New instruiment panel

I read that if i disconnect the MAP sensor and the engine tone doesnt change then that might be the fault. But unsure where that sensor is.

SOoooo please any help be great! And if ive missed anything obvious then ask and ill answer.
Im in Denmark WA and any parts firstly cost a bomb and secondly take ages to get here... so id like to have an educated guess before i go ahead and order anything.


Many thanks for reading.

[Sunny43.5]

First thing welcome to the Forum hope you enjoy the visits , there are several mechanics who contribute on the Forum so I am sure they will start soon with ideas and suggestions . The T4 is a great drive strong engine [when running properly in your case]so I hope it gets sorted .

[Umai Naa!!]

Air mass sensor is mounted to the air filter housing. The intake air passes through the sensor before going into the engine.

[vw pirelli]

where do u start buddy!! try checking the idle control valve, cam timing, fuel pressure, air leaks and even check your earth....

[deadroo]

Air mass sensor is mounted to the air filter housing. The intake air passes through the sensor before going into the engine.

Is there aa way of testing it? Are they known for going?

[deadroo]

I've just disconnected the sensor on throttle body and that has made it run smooth and not cut out..... is that called throttle position sensor? And if left unattached will it cause any further problems?
Any help?