Mid range miss-fire

[BlackV70]

My 1999 V70 T-5 has developed a slight miss-fire but only at mid range revs. I suspect that it may have a duff coil but am having diagnosing which one.

Replacements are EUR125 +VAT each so I don't fancy replacing all five to fix the problem.

Anyone know any tricks to find the right one?

[thunderace]

you've done a recent '0' service?

[adriancole]

My 1999 V70 T-5 has developed a slight miss-fire but only at mid range revs. I suspect that it may have a duff coil but am having diagnosing which one.

Replacements are EUR125 +VAT each so I don't fancy replacing all five to fix the problem.

Anyone know any tricks to find the right one?


Bizzarly, SNAP!!

Not my ETM as that is new, misses at around 2.5 to 3000 rpm, esp on motorway....no codes showing....

Been wondering what it could be......

[BlackV70]

you've done a recent '0' service?


Yup, even the fuel filter. Swapped out my 10K old NGK plugs today for OEM ones, not much improvement. The old plugs were evenly coloured which was also a bit confusing.

My local Volvo specialist just serviced the car, they suggested I borrow a set of coils from one of their "known good" second hand cars as an experiment so I will do that first (friendly people the Dutch).

The problem then comes when I have to figure out which of my coils are duff, they are too expensive to buy a set if I only need one or two.

Another shot in the dark - the car has RICA 310 but is running a standard air filter, not sure if this would cause a problem or not?

[Vikingxl]

Ideally you need to fingd someone you can borrow one off and then work from there

[volvotuning]

Have you checked the fault codes????

The first thing you should always do is check the fault codes. If there is a misfire, the ECU should tell you on which cylinder it is.

Also, what plugs are in there?

Another option is to book in with us and we can check it out for you. Or go to RICA in Holland. There's also PW Cars in Beaconsfield nr Slough. They are a RICA installer and are also familiar with diagnosing performance problems.

Adam.

[thunderace]

Another shot in the dark - the car has RICA 310 but is running a standard air filter, not sure if this would cause a problem or not?

how grubby is it? lol

[BlackV70]

Have you checked the fault codes????

The first thing you should always do is check the fault codes. If there is a misfire, the ECU should tell you on which cylinder it is.

Also, what plugs are in there?

Finally, why not book in with us and we can check it out for you. Or go to RICA in Holland. There's also PW Cars in Beaconsfield nr Slough. They are a RICA installer and are also familiar with diagnosing performance problems.

Adam.

Is it possible to have codes related to these symptoms registered in the ECU without getting a "check engine" light?

Until today the plugs were NGK as recomended, my local Volvo garage replaced them with Volvo packaged OEM plugs as an elimination exercise. This change appeared to make little noticable improvement.

A visit to RICA in Holland may be an option, I'm way up in the north though so its quite a hike.

Seems like theres been a gradual decay in performance over time, either that or I've become used to the RICA lol. I live near the German border so autobahning provides regular entertainment.

[volvotuning]

Is it possible to have codes related to these symptoms registered in the ECU without getting a "check engine" light?

Yes. Many faults are logged without the check engine light showing, including misfires.

If not ignition, then other possible causes could be ETM/throttle pedal related, or an air leak somewhere. Over time these should log a code too.

I would check the fault codes first. If there are any, it will save you a lot of hassle and money guessing what the problem is.

Adam.

[adriancole]

Have you checked the fault codes????

There's also PW Cars in Beaconsfield nr Slough. They are a RICA installer and are also familiar with diagnosing performance problems.

Adam.

Their diagnostic method is simply to plug in a code reader and say "no codes showing" when clearly there is something wrong with my car.

I was in the area for a couple of days (Beaconsfield) and thought, oh ill give them a go (PWCars).....great for changing disks, cannot fault that, totally useless at finding faults......not the service i am after....

That and the garage was a tip...old paper rags all over the floor, crap everywhere on the floor to be honest...and it wasnt the days work either...got there when it opened and was a little dissapointed to see all the rubbish lying about...same when went to pick up car.......

Summery, good for changing stuff, rubbish for fault finding, rubbish lying everywhere.

And I still have a missfire.....

[volvotuning]

Their diagnostic method is simply to plug in a code reader and say "no codes showing" when clearly there is something wrong with my car.

I was in the area for a couple of days (Beaconsfield) and thought, oh ill give them a go (PWCars).....great for changing disks, cannot fault that, totally useless at finding faults......not the service i am after....

That and the garage was a tip...old paper rags all over the floor, crap everywhere on the floor to be honest...and it wasnt the days work either...got there when it opened and was a little dissapointed to see all the rubbish lying about...same when went to pick up car.......

Summery, good for changing stuff, rubbish for fault finding, rubbish lying everywhere.

And I still have a missfire.....

All I can say is that when they diagnose running problems with RICA tuned cars, they often consult with us to try and resolve the problems. Whether they get the same level of support from their other software suppliers, I really could not say.

Adam.

[chewy]

I had similar sort of problems, I described it to my main dealer and said it sounded like a misfire.
On mine the the ECU light came on and stayed on. Apparently it was the pressure control valve sticking.
The boost comes in around these revs and it couldn't make its mind up to open or close hence the juddering. The fault code was "low boost pressure". Some times it would stay open and you could spin the wheels in 1st 2nd and 3rd... scary really.
Think the valve was £70 and everything is running fine now.:rally_dri

[adriancole]

All I can say is that when they diagnose running problems with RICA tuned cars, they often consult with us to try and resolve the problems. Whether they get the same level of support from their other software suppliers, I really could not say.

Adam.


Thank you for you good reply, though one thing I can add, when they had my car it was in plain vanilla tune.....as it left the factory....(give or take a dealer software upgrade...)...so one can deduce it is a mechanical/electrical prob rather than software.....

Currently playing a waiting game to see how much worse it can get......

Adrian

[BlackV70]

Five new coils are on order. The loaned ones have fixed the misfire problem a treat - smooth power all the way to the red. The car has a lot of it's old character back and feels light on it's feet!

It's certainly worth borrowing a set from a known good car to aid diagnosis.