1997 V70R... does she have a MAP sensor?

[Spooky]

Having problems with little to no boost. Just noticed it tonight on an M-way drive. Looked at my boost gauge when i kicked her down and it didnt even go over 0 !!!

Someone said it could be the boost sensor which i believe is also known as the MAP sensor. Although some research has led me to believe these are only installed on a car with ETM which for Volvos was on 98+ and mines a 97?

going to check the actuator tomorrow but just asking in case i need one or those or whatever the equivalent is for her.

[stribo]

Fairly sure it doesn't have one mate.

[Spooky]

Fairly sure it doesn't have one mate.

cheers pal. May have to try the MAF then hahaha.

She is throwing up an error and i got a code reader but when i try read the code its telling me there is no new code to read... but still lets me clear it ! getting no boost at all. When i kick her down my boost gauge is showing just below 0 psi so there is defo something a miss somewhere.

[stribo]

Check all your vac hoses as well.

[Spooky]

Apparently there is a sensor at the back of the drivers head light to check as well?

[Spooky]

Anybody know what the sensor is at the back of the drivers light and is there anything to clean on it other than the connections?

I have a pic of it if needed.

[Spooky]

OK so I have been having a rummage around and found a small crack on this pipe. You cant really see if from the pic so i have marked where it is. This is coming from the induction pipe from the back of the filter.



would this cause a loss of boost?

Also, does anyone know where i can get a replacement hose of this please?



as im pretty sure this wont be helping either!

[stribo]

Neither of those hoses would cause a lack of boost, as they are both before the turbo. The small pipe is part of the PCV, and will need replacing, as it'll be letting in unmetered air.

[Dangerous Dave]

On Motronic 4.4 cars there is a sensor (sometimes picked up by code readers as a pressure sensor) behind the right headlight, known as the barometric pressure sensor. This is to detect what altitude the car is at so the fuelling,etc. can be adjusted.

The manifold pressure sensor was on ME7 cars (99ish on)

Since you're not getting any pressure it sounds like you have a leak in the pressure side of the intake after the turbo. the best way to find it is to pressurise the intake system which should show up a leak. I have done this myself by gaffer taping a length of garden hose to the turbo inlet and blowing into it (super simple and bodged I know, but works) otherwise you can rig up a compressor to it and pressurise that way. I found out my injector seals were leaking by doing this test.

Either that or there is something wrong with the turbo actuator, possibly stuck open?

[Spooky]

will give that a go... cheers Dave

[Spooky]

Could anyone tell me how to check the actuator at all? Is it just a case of reaching in getting hold of it and trying to move it from side to side? Should it take a bit of effort?

[Ettienne]

Could be TCV although even when knackered they boost still.

Check your purge and vac tree as well, people forget these on the inlet manifolds.

Should be quite obvious also wd40 carb cleaner or similar, spray around the engine whilst running, all joints hoses.

Sucking in will upset tickover a known one to split is the throttle body where it goes to the icv.

As Dave says pressurise is the best way, wd40 can be done quickly and cheaply.

[Spooky]

Ok the latest episode in this sage!!

So im tonking along the M1 tonight at just under 80 with the CC on as i always do. get to a hill and i notice we are slowing down. Look at the speedo and its slowly going down and down and down!!

I go put my foot on the acelerator and notice that its flat to the floor! Indicate to pull over whilst trying to remember RAC's number and i happen to knock off the CC and put my foot on the accelerator and she picks back up again!

flick CC back on and she boots down but is going nowhere fast and the accelerator is again flat to the floor.

I could hear something from under the hood, not sure if it was a sucking or blowing of air, but I could defo hear it. She's never done this before and I make the same trip every 2 weeks and drive it with CC on every time.

Does this pinpoint hoses as opposed to actuator?

[Dangerous Dave]

If you can air rushing somewhere then it does sound more like a leak.

There is one more way you can quickly pressurise the system, undo the intake pipe from just after the MAF and blow into it making a seal with your cheeks. Usually it will pressurise straight away with some minor leaks along the system. If you don't get any pressure at all then you have a big leak, you should be able to pinpoint it with a little trial and error.

[Ettienne]

Ok the latest episode in this sage!!

So im tonking along the M1 tonight at just under 80 with the CC on as i always do. get to a hill and i notice we are slowing down. Look at the speedo and its slowly going down and down and down!!

I go put my foot on the acelerator and notice that its flat to the floor! Indicate to pull over whilst trying to remember RAC's number and i happen to knock off the CC and put my foot on the accelerator and she picks back up again!

flick CC back on and she boots down but is going nowhere fast and the accelerator is again flat to the floor.

I could hear something from under the hood, not sure if it was a sucking or blowing of air, but I could defo hear it. She's never done this before and I make the same trip every 2 weeks and drive it with CC on every time.

Does this pinpoint hoses as opposed to actuator?

Or a split in the pedal diaphragm which is quite common, especially if it's on cc.

[Spooky]

Thanks guys. That's my job for this weekend sorted then and fortunately I am taking the filter out to clean it as well so I can kill 2 birds with 1 stone

[Dangerous Dave]

Cool, let us know how you get on

[Spooky]

Will do dave. what's the pedal diaphragm out of interest