lasercowboy
Normally you get special MAF cleaner (no idea what's in it) and use it to clean the wire itself.
Nosi
hi, if you google ' Volvo 240 airbox mod', you will get some pics. but the basis is that inside the airbox is a valve that is supposed to allow hot air ( routed thru the duct that goes to the exhaust manifold) when the engine is cold, then when the engine has warmed up, the flap closes and you only get 'cold' air from the grill intake. in 240s and others , the flap tends to get stuck in the hot position. this creates some confusion for both kjet and fi engines. as I live in bundy, I remove the valve and the duct and tape up the duct hole, so I only ever get cold air.
the maf ( mass airflow sensor) is also known as air flow meter, is the black box gizmo between the airbox and the throttle body. kjet motors don't have this. you can easily unplug it and undo the hose clams and remove it. there is usually a ss gauze protecting the little wires that actually do he metering. spray liberally thru the gauze to clean the wire sensor. usually the wire sensor will be black with crud when you start, and nice and shiny when you finish. wait for it to dry for a few minutes, then put it all back together. do not smoke while performing this, a it could be very bad for your health. maf cleaner or electronics circuit cleaner are basically the same stuff, available form repco or supercheap or similar. depending on how dirty it was, you can achieve a noticeable improvement in performance and consumption.
Nosi
another fuel tip - I have learned over the years, for electronic fuel injected motors, is to ensure you have the correct thermostat in the cooling system.
some people will remove the thermostat, or put a cooler one in. what happens is that the engine never gets to the correct operating temperature, and then the fuel system sensors think that the car is still 'warming up', so it does what it is programed to do, and 'chokes' the motor by adding extra fuel. just like driving a carby fuelled car with the choke on all the time.
I have never personally had this happen on a Volvo,( all of mine have had the correct thermostat ) but it definitely did happen on a ford that I owned.
( for kjet motors there is a 'control pressure regulator' that acts as a choke, but I am not sure if it is capable of discerning only slight variations in engine temperature. in any case, I would still run the correct thermostat )
240
Thanks for that! It's quite useful, I'll try doing what you said.
I live in Canberra where it can range from -5° in the morning in winter to 40° in summer, so my best option is probably to make sure that flap is just working properly.
With the thermostat - my temp gauge runs pretty much in the middle, can I assume from that that the correct thermostat is installed?
Nosi
first thing to do, is to consider moving somewhere else !
but based on what you say, i would guess your thermostat is ok, as you live in a place where it would be silly to remove it. ( assuming your car has been locally owned )
when you next get the chance, after starting from cold, keep an eye on the temp gauge. as you drive, for the first 4 minutes or so, the needle will progressively rise, until it actually rises above middle. then suddenly it will drop back to the middle position you talk about. this is evidence that there is a thermostat installed, and that it is functioning correctly.
I am not sure how to test the airbox flap, as I always remove them, and every one I removed was stuck tight. google may be your friend to find how to test a functioning one. perhaps others ( south of the tweed ) will advise their opinions on the flap???
Anthony
240;62934 wroteThanks for that! It's quite useful, I'll try doing what you said.
I live in Canberra where it can range from -5° in the morning in winter to 40° in summer, so my best option is probably to make sure that flap is just working properly.
With the thermostat - my temp gauge runs pretty much in the middle, can I assume from that that the correct thermostat is installed?
If you use a heatgun on the sensor (and flap) inside you can test.
Once engine is warm, the last thing you want performance and engine stress wise is hot air being inputted into the engine.
If you decide to remove all the flap complication, advice is to block the large dia port/hole.
240
Anthony do you personally think it's better to remove the flap or to leave it there, making sure it's working properly?
lasercowboy
Spurred on by this thread, I took my airbox apart and tested my 'thermostat' tube. Knackered, unsuprisingly. Could only move the baffle about 1cm at most, nowhere near enough to switch between hot and cold air. That explains the extra latent heat in the engine bay i guess.
So for now, I've taken the assembly out and covered the hot air port. I assume it's going to be no problem throughout the summer, and I might reassess in the winter (although the body of evidence on TB and other forums says not to bother!).
Au revoir broken flappy paddle thing, bonjour lovely cool air!
paul0075
IPD sell the replacement thermo bit for the flappy part
egads (she/her)
A couple of days when it was -5 ish driving to work I got a frozen throttle plate. If you don't do snow/highlands work probably not worth switching back.
240
Rico - Is there much difference when driving it?
lasercowboy
Yep i saw on FCP too, $12.... I'll probably 'do the right thing' and chuck one on my next order in either case. But interested to try for a while with cold air (I've clearly been pulling purely hot for a while) and see if there is any difference.
I'm in Melbourne, so we get maybe 2 days a year below zero in the 'burbs.
lasercowboy
@240 - i don't know, i literally did it 20 minutes ago after reading this thread ;)
I'll let you know in a day or two.
GingerNinja
Had a 300+ km highway run on the weekend and got 8.5L per 100km in the turbo wagon.
volvodriverman
GingerNinja;63211 wroteHad a 300+ km highway run on the weekend and got 8.5L per 100km in the turbo wagon.
That's awesome, I had it down to 9 on the run up to Brisbane with the ac on the whole way. Such a good combo! How's the old bus going?
A_Volvo_Driver
The Moose would get about 350-400km on a tank. K-Jet, mostly city driving and a fun M45/3.91 diff combination.
We deleted the preheat hose, but I don't think that we blocked the airbox.
