Engine: TD: Volvo s40 slow acceleration / sluggish

[hasitha]

The Car feels like it is pulling something, i have checked the EGR valve ( the previous owner has blanked it, however i cleaning it and reinstalled just for the sake of removing it ), replaced the MAF sensor ( then did the multimeter test to check if the new MAF actually worked.. I think it is a green light, but i will scan it soon. there was a crack on the intake line to the turbo from the air filter box ( crack was close to the jubilee clip which tighten the intake hose to the turbo inlet), sealed it with silicon ( a good hose is on the way). Oh and yesterday i found out that the vacuum line which goes to the throttle body was also damaged. and when shutting of the engine the throttle body didnt work, so i super glued the rubber hose together, actually a new valve (governor) & hose is on the way. but there are no signs of improvement. After super gluing the throttle body ( shut off valve) worked when ignition is turned off. Is there any other function of the throttle body in a diesel? ( i actually don'r know much about this since this is my first diesel car) because it doesn't seem to move when accelerating. only time it works is when i turn off the ignition.

The car also has a very hard time reving up above 3000 rpms as you can see in the video. i have floored the accelerating pedal and the car is not moving even in 3rd gear.

Im from Sri Lanka, so please excuse the foreign language in the video ( i didnt intend using this clip for youtube or the volvo forum ) , i do mention the changing gears in English , like 2rd..... 3rd.... if you could hear then you could understand how the car moves in each gear, Please note that in the entire video my foot is floored, only released the pedal to shift gears.

I have a video in which the car is trying to climb a small hill, in which shifting to 3rd is difficult and the cars slows down in 3rd even when floored. I will upload it soon.

Any help would be greatly appreciated.

The car is a 2001 Volvo s40 1.9 TD

THE VIDEO
https://www.youtube.com/watch?v=iehCPVJaEZg

[skyship007]

It sounds like the ECU has gone into, "Limp home mode". There are a number of reasons it might do that and a dirty of broken MAF sensor is probably top of the list. If disconnecting it improves the performance, then the sensor is forked. I hope you did not fit a new one off Fleabay, as the non Siemens ones don't seem to work too well.

Once you have ruled out the MAF sensor and fuel filter, it's best to get the hidden fault codes read. If possible, get them deleted and then see which ones occur again. There must be about half a dozen other systems thay can cause a limp mode. Turbo boost pressure regulator, fuel pressure regulator, RPM, EGR, crank position and MAF sensors etc.

Obviously a hole in a turbo hose or vacuum hose can produce similar symptoms. An EGR will not suddenly foul up and when it does, it will just cause a lag during acceleration.

[neanderthal]

as skyship has said get your codes read, as can save you guessing/money.and hope you bought a genuine maf sensor..do you have an n75 valve on the bulkhead,as you may have a leak from one of the small pipes.or the valve itself may be faulty.as mine was,and now runs great apart from an odd flat spot.

[hasitha]

Thank you skyship007 for replying.

I couldn't mention this before.. before i installed the MAF, i had a friend of mine scan the car, then only i ordered the MAF as there was an error saying " Air Mass Meter- Permanent " below is the is the errors i got from scanning the car and after deleting the error codes, those re-appeared.
1. 181C - Preheating Light. Signal too low - Permanent
2. 1806 - Air Mass Meter - Permanent
3. Fan Unit High Speed. Signal too Low - Permanent


Well i couldn't find the Siemens one here in Sri Lanka, so i ordered one from ebay i reckon it was from china. While i was searching the regrading this issue there were many who said that the cheap Chinese ones actually didnt work. maybe you and everyone else is right. but like i said i tested the MAF with a multimeter and it showed a reading of 2.8volts at about 2000 rpm and did gradually increase as i rev up. anyways its best to get i scanned and check whether the error codes still appear.
There was an error code saying "Fan Unit High Speed . Signal too low" what does that mean does that hinder the performance. the car doesnt heat up too , the dashboard reading is not alarming..

I am planning to order a New Siemens one if the error shows up after scanning. what do you think? do you think i should buy a Siemens one if the error code has disappeared?

Like you have said, i decided to change the fuel filter today ( after the videos i have made, Because i too felt that its better to change the filters and see)
Here is a photo of the filters


and few mins ago i did the reinstall , installed a MANN filter. the one which was in was a unbranded one. BUT NOW I THINK I HAVE MESSED UP!!!
After changing the filter and cranking up the car it started for about 10 seconds but i coudn't hold a higher rpm and it stalled. i also didn't fully fill the diesel filter housing with diesel.
Now its cranking but won't start, i removed a fuel line which goes from the fuel rail to the injectors ( loosened the nut from the injector side) and there is no pressure while cranking there was nothing coming out from the line and after few seconds there were air bubbles and then diesel started pouring out but had air bubbles. and there wasn't any pressure and again diesel stopped coming out and then again in few seconds diesel came.. but not pressurized. now i stopped cranking and let the starter motor and the engine cool down, and started doing some research . Maybe there is much more air in the system right? I am afraid to crank it alot as it might damage the starter motor? and will there be any damages to the fuel pump if i continue doing this till the air runs out?
Or is there any other way in which i could bleed the air out? If anyone has faced similar issues or knows a thread which this issue has been discussed.
Please let me know.

[hasitha]

Thank you neanderthal for replying

Here is where the cracks are
**Intake hose - Fixed it with silicon but a new one is on the way.



** The line which connects to the Throttle body. - I super glued it- planning to get a new valve because the crack is straight from the valve housing - this is located below the vacuum tank.



I Checked the the turbo solenoid valve as well and from the looks of it seems to work, as i start her up , the turbo actuators moves. but like you said it could have some issues but since it didnt showed up in the previous scan i didnt take much concern. but i checked the vac line to the valve but there were no cracks but im not sure if the crack which you can see in the above photo affect functioning of the turbo solenoid valve as well.


But now my main problem is bleeding the air from the fuel system
any help would be greatly appreciated.

[Griffithsbilly88]

A hand priming pump would help bleed it plus it will take a while if the filter housing wasn't filled with fuel. https://www.tool-net.co.uk/p-363888/...FQccGwod12cAEw

[skyship007]

As Billy said, you must use the primer bulb that is located next to the fuel filter housing. Pump until the rubber bulb feels hard.

The pre heater code is a common one and it does not matter unless you live in the Artic. One of the glow plugs is probably kaput, or if there is no power with the key in position 2 the relay or fuse has blown. I would ignore that one.

The fan unit high speed signal too low is interesting, as I've not seen that mentioned before and I can't find it listed. I presume it's the heater fan?

Can you get the codes read again to see if the MAF one is still there??

[Biotoxic]

Hi, just to let you know that after you have primed the fuel filter housing it will take some time to for the air to clear the fuel lines. Expect a rough running once you have managed to start the engine. Once it starts let it idle for lets say a minute and then slowly increase the rpms up to the 3-3.5 rpms and do this a few times(or until there is no more rough running). There might be a problem the next time you will start the engine, but is should be ok after all.

P.S. The valve you call it a throttle body valve is actually called a butterfly valve/shut off a.k.a. shut down valve on diesel engines. Throttle body supply air on request on the petrol(unleaded) engines, but on diesel engines what looks like a throttle body(shut off valve) acts as a means of limiting air supplied to a engine. So once its closed there is no more air available for combustion to take place in the cylinder thus shutting down the engine. Although once you switch the ignition off, there is no more electricity supplied to a injectors thus no more diesel/petrol is being sprayed into a cylinder and combustion should NOT take place, although there is a chance that if the pistons are still moving engine theoretically could start on its own... thats why there is a air shut off valve a.k.a butterfly valve fitted before the intake manifold to stop the air going into a combustion chamber.
Take a look at the Fire Safety Triangle What Engine Control Module does in diesel cars is it cuts off supply to diesel, no diesel means no bang. It removes one of the three required elements to start/continue the fire, but to be on the safe side it also starves the engine of air.. thats 2 elements less to start the fire, there is no chance that ignition will take place.
Its similar to a petrol engines, but since petrol doesn't want to ignite when under pressure the ECU cuts off the fuel AND also electricity to the spark plugs. Thats another two elements less from three for a fire to start or continue to burn.

By the way for the reference.. if you ever have a runaway turbo, you can manually press on to the air shut off valve's actuator to starve the engine of air(if you are not in a car off course). You should be able to lift the engine cover and locate it with your finger tips. You never know... it might come in handy one day..

[hasitha]

Thanks Griffithsbilly88 for letting me know about the hand priming pump.

And thank you skyship007 for letting me know where it is located..

Because of you guys i Started the car yesterday.. I hand pumped until it was hard and then let it sit for a while then again squeezed on it till it was hard and then rested .. did that for few times.. and slightly opened a fuel line to the injectors and told my mom to crank up the car while i was squeezing the hand prime pump. and volaaaa the car started after few seconds and then let the HP pump push out any air in the system through the slightly loosened fuel line .. ( hell it was a mess .. diesel was shooting out and no bubbles... and while the engine was running i tighten up the fuel line... and ran the car for a test run and it was great .

BUT the main problem still remains...

I will get the car scanned soon. I ordered a Bluetooth OBD2 scanner from ebay, it was very cheap .. but i found reviews that it was good and was able to read codes and delete them. not sure though.

Yes skyship the fan seed thing is another thing which worries me. if you find anything on it please let me know. i did research in the internet and no luck . FYI there is a fan in-front of the radiator and it works sometimes. and after long runs the fan stays on for few mins and then shuts down. and there is another fan which is located behind the radiator and it works when the AC is on. Just letting you know. to find out if there is anything abnormal .

I will let you know about the MAF error as soon as i scan the car.

Guys could it be an issue with the Turbo vanes as i read that this has a VNT turbo.
here is a photo of the turbo. it looks good from the intake side.. i couldn't ask the previous owner whether he replaced it or not because he has gone overseas.


as you guys must have seen the video. could it be that the turbo vanes doesnt open up properly to give the right amount of boost . because when the car is at about 3000 rpm the engine feels like it will blow if i rev it more . ( exaggerating a little bit ) what i am tyring to say it when in gear it feels very hard to accelerate above 3000 rpms as if the engine is at its peak rpm. but if i hold the pedal down it gradually and slightly moves up but i think even in a diesel engine the vehicle should move fast at high rpms. ( the cars revs up easily above 3000rpm when not in gear)

I saw the video on youtube. a 2001 V40 accelarating from 0-100kmph and wow i wish mine was like that.
https://www.youtube.com/watch?v=Kl9dBkE_mzk


Please kindly let me know if this could be a turbo issue.. yesterday and a few days back i heard a rattling noise from exhaust side , heard like it was coming from the turbo, but there isn't a pinch of black smoke coming out the tailpipes so the turbo turbines might be working. could it be that the vanes are damaged?

Please note that the egr valve is blanked/ blocked in this car. i will order a egr valve soon. i hope it doesnt have to do with the performance with as i have read if it is closed it will improve the performance. anyways i will replace it as it is the way the factory meant it to run.


I cleaned it anyways .. there is a blanking plate. so the egr doesn't work.


And Biotoxic thank you very much for the information. i had never heard of a runaway turbo. the video is crazy haha.. thanks for the information on the shut off valve.. i actually was confused since it only moved when i was turning off the engine.. and now i know it the only job it does. thanks again.

[V40DSchariot]

Hi Hasitha and welcome to the forum,
The shut off valve that Biotoxic mentions is controlled by a solenoid, check the solenoid to ensure that air is not passing through. If you pull the small vac pipe off before the solenoid and seal up then run your car, that will tell if it's that solenoid or not. Be carefull when pulling off the small pipes as they can get stuck and snap the little plastic tips.
I had that on my diesel, car would'nt rev over 3000rpm under load, slowed down up hills, felt like it would stall at any moment and felt like it wanted to continue running after shut off.
With the solenoid gone on mine it allowed air to pass straight through into the air intake into the cylinders, which should only be compressed air from the turbo.
Take a look at my thread from that problem.
http://www.volvoforums.org.uk/showth...=179816&page=3