Hi there, I was wondering if any one could help. I have recently bought a 99 C70 2.4T. It was running fine for the first few days (350 miles) and then started mis-firing abit and having problems starting. It is really intermittent though and it will behave in the following ways:

1) Starts on the button and run perfectly
2) Starts fine but have a rough idle and the idle speed will go up and down. When it is like this it is easy to stall and will often stall when the car is put into neural.
3) Have real problems starting. The worst I have had so far is taking 45 mins to get it started. What it would do is either just tun over and not fire or it would fire but run at about 500 rpm really, really badly.... It almost sounds like it is not firing on all cylinders and the enging moves forward and back on its mounts. when it is doing this it you can put your foot all the way to the floor and it has no effect at all. The engine will continue to run like this although I tend to turn it off withing a minute or so as I worry about the CAT.

I did (not surprisingly) have the engine management light come on which according to my (not very friendly or helpful) local volvo specialist it was pointing to the MAF as it had two error codes related to incorrect fuel mixture and another pointing to an air leak into the air inlet system (they say they have checked this for leaks). The garage reset the code and it ran perfectly. I replaced the MAF as a precaution and it continued to run with out problem for 100 miles before the engine management light came on and it was again running like a bag of nails. The garage now the error (same codes) and says it is either a faulty MAF (new bosch unit and seems strange that it is giving the exact same fault) or throttle sensor.

Anyway they have suggested that I keep driving it and hope that what ever is causing the problem fails (thanks garage, really useful!)....

Just wanted to know is anyone has had similar problems or can suggest a way I can troubleshoot the cause without throwing too much money at it?

Couple of other things, when the error has been reset when I say it runs perfectly (nothing is ever perfect) I have noticed a couple of things, firstly the idle is not totally regular when driving it often hunts slightly (although no where near as bad as when the EM light is on). Second thing is that I have often noticed a slight power surge (difficult to describe except it is the opposite of a flat spot) in normal driving conditions. I have a manual box but it almost feels like the sort of surge/ uneven power you get at very low speeds with a tired auto box. This tend to happen anywhere between 20 and 70 mph, could be completely unrelated!

Any advise/ ideas will be apprciated,

Matthew
Bristol, UK

Have you had the throttle body cleaned lately?

Having just bought the car I do not know if it has been done recently...... would it be likely that it would cause an intermittent problem?

I did check the spark plugs and one of them seems to be getting black carbon build up when the rest of them are fine.... would this be a sympton or would all of the cylinders run rich?

With regards to cleaning the throttle body is this something I can do or is it a garage job? I have read a thread about about how to remove the unit but what do I need to clean it with? Do I need special chemicals? I have come across a company in the UK www.bba-reman.com that will 're-manufacture' the part for £150 + postage replacing the faulty electrics. They remanufacture your own unit which saved recoding issues. They offer a two year guarantee..... what do you think.....sounds like a good deal?

If I can get the unit off myself and refit it it will probably cost not more to do this than to get it cleaned by a garage......

Many thanks,

Matthew

Your c70 has an electronic throttle body..............I do not believe the site you mentioned rebuilds them................ I took my c70 to the dealer for the cleaning..............it was not costly and the vehicle's mileage shot up dramatically!

cleaning the TB should not damage anything, just make sure you use a TB cleaner that says its safe for sensors if you leave the TB on and spray the cleaner in there. also i dont know if volvos have a TPS sensor but if they do it should be located right by the TB. clean that with TB cleaner as well and that should help with the idling problem.....hopefully.

The throttle body has a TP sensor built in the throttle body.It is all electronic no throttle cable.
I suggest to remove it to clean it.Because it is located under the intake manifold.

Thanks for all of your help and advice, it is much appreciated.... I will take the unit off and see if it looks like it needs a clean, if so I will give that a go.

Regarding the link for the company that manufactures the units I must admit it is pretty difficult to find the right part... look at this link and see if you think it is the right part....

www.bba-reman.com/content.aspx?content=volvo_post_1999_marelli_elect ronic_throttle_system

I found the manufactured unit advertised on ebay......

http://cgi.ebay.co.uk/Volvo-Marelli-Electronic-Throttle-System_W0QQitemZ4562595791QQcategoryZ10432QQssPage NameZWDVWQQrdZ1QQcmdZViewItem

If you can't get the ebay link to work go to ebay.co.uk and search for electronic throttle and you should find it. The company is advertising the remanufacture of the units every day.

What they claim is that because they remaufacture the suspect components it will be a more reliable and stable unit than the original, hence the two year guarantee that they are offering.....

It is obviously a much cheaper route than replacing the unit.......Any thoughts would be appreciated.

Matthew

That appears to be the unit. Let's wait and let Tech comment. However...................Volvo just recently has stated: "We have decided to treat this matter generously". This is a response to the projected 94% failure rate of the Italian throttle. Volvo went on to say: "Those that have paid for the repair themselves will be reimbursed". Whereas I have had my throttle cleaned in a low mileage c70.......................and will continue to have the dealer clean it every 20,000 miles..................I am now more "rested" knowing that Volvo purports to stand behind the throttle for their customers. It is my intention to keep this auto for a period of time rather than exchanging it for a new vehicle at three years.

First I would let Volvo fix it for free with the new things they are doing.

Second if you buy one of them it will still be a pain i the A**.You will buy it and install it.Then you will pay to have it towed to the dealer.Then you will pay the dealer to program it so it will run.

Is it worth the Headaches?

You put it much better than I did with my posting Tech. That was precisely what I was trying to get across!! Evidently Volvo is going to warrantee these throttles for 100,000 miles..................not bad!!!

Thanks for you help/ views guys, much appreciated.

Great news that it looks like Volvo is admitting that they have a problem

My car has just had it's 114,000 miles service (Volvo up to 70K and then Volvo specialists) so I do not think Volvo would entertain any claims from me. I do not know if it has been replaced before and as a recent new owner (3rd) I do not think I would find it easy to prove if it had.

I will clean the throttle this weekend and see if it does the trick..... if not I will call Volvo and see if I can get a favorable response, if not I will go down the re-manufactured route.

Two points on the re-manufactured units...... (I am not a sales man for them! Just what I have read in the Ad/ on their website)

'BBA can do an own unit rebuild, with all work coming with a 2 year warranty. If you purchase a new replacement, you will also have to pay to have it coded to your vehicle at the dealer. An own unit rebuild obviously removes this cost.' ............so I would not need to have it reprogrammed, they collect it and then re-deliver it 2/3 days later.

BBA claim that since they remanufacture the units (not rebuild) they do not repeat the weaknesses of the original part so they should be more reliable......whats more they want to expand their part offering so if you have a part that they believe other people will be intererested in (typicall parts that sell in the main dealer for £350 or more) they will remanufacture it for free and if they then go on to re-manufacture that part more than 10 times in a 6 month period they will give you £1000.....could be bull, as it is impossible to check.....do have a USA office as well though.....

Anyway this company could be useful for some others who have high milage cars....

Thanks again,

Matthew

Keep us posted on the re-man if that is the route you take. There are a zillion owners who would certainly be interested in an upgraded re-build! I wonder what it is that is rebuilt to a higher standard than what was original? If you do go the re-man route, I would ask the builder what he has replaced in his units that make them more reliable.
Reg

Something still sounds fishy.If you replace any of the electrical parts in there they will need to be reprogramed to the car.