Misfire under load on the T4

[Dave86]

Started about 2 weeks ago with the odd hiccup when i put my foot down got worse over the last week so went and fitted new plugs on Sunday and ordered new leads and both coil packs. I went to pick them up today and the leads were the right ones but the coil packs were wrong so hopefully they will be in tomorrow. However with the new plugs and leads the misfire is even worse, checked the spark plug gap and all the connections and they're all fine so im hoping that its the coils failing other than that what else could it be?

[mitchyboy01]

Misfire under load my bet is on coilpacks. I have 2 spare. You can borrow these if you want to troubleshoot before you buy?

[Dave86]

Misfire under load my bet is on coilpacks. I have 2 spare. You can borrow these if you want to troubleshoot before you buy?

Cheers for the offer mate but I've ordered them, they should be here tomorrow and im going away to devon on Friday morning for a week and haven't really got the time to come and get them. :)

[Haizum74]

Cheers for the offer mate but I've ordered them, they should be here tomorrow and im going away to devon on Friday morning for a week and haven't really got the time to come and get them. :)

Yeh if sparks havent solved it its usually coil packs thats the next bet.

[merc85]

I reckon it could be Crank/flywheel sensor mate,

[Haizum74]

I reckon it could be Crank/flywheel sensor mate,

Would that throw a code at all?

[Dave86]

I reckon it could be Crank/flywheel sensor mate,

Cheers mate that will be next on the list if the coilpacks don't solve the problem

[960kg]

What new plugs at what gap?? Your a T4, very fussy!

Misfire under boost damn nigh always ignition!

Just have to find the culprit.

[Dave86]

What new plugs at what gap?? Your a T4, very fussy!

Misfire under boost damn nigh always ignition!

Just have to find the culprit.

New bosch plugs set at 0.75

[960kg]

New bosch plugs set at 0.75

Only in my own opinion I would be very surprised if it wasn`t your plugs!!

It sounds very strange but on a standard T4 the plugs to use are Volvo own ones with no problems. The Volvo part number is 272344-3 and is a different number to all the other models, so that means it must be important.

[Haizum74]

Only in my own opinion I would be very surprised if it wasn`t your plugs!!

It sounds very strange but on a standard T4 the plugs to use are Volvo own ones with no problems. The Volvo part number is 272344-3 and is a different number to all the other models, so that means it must be important.

Yeh its a bit hit and miss with non volvo plugs on them, some are fine others aren't. Not come across any issues with volvo ones so far.

[fassi1]

Fuel pump or fuel pressure regulator.
Lean mixture can cause misfire under high load.
It would be very helpfull to check fuel trims.
If it's coil pack then fuel trims will be negative cause fuel doesn't get burned and ECU will try to lean the mixture.
If it's low fuel pressure then fuel trims will be positive cause ECU will try to enrich the mixture.
Take the spark plugs out.
If they are covered in dark smokes that means there is problem with the ignition.

[Dave86]

Only in my own opinion I would be very surprised if it wasn`t your plugs!!

It sounds very strange but on a standard T4 the plugs to use are Volvo own ones with no problems. The Volvo part number is 272344-3 and is a different number to all the other models, so that means it must be important.


Yeh its a bit hit and miss with non volvo plugs on them, some are fine others aren't. Not come across any issues with volvo ones so far.

Fair enough although the genuine plugs that were in the car look nearly new anyway i only changed them to rule them out. If the new coil packs don't improve the situation ill get some new genuine plugs.
Bit annoyed at having to spend money on it really as i don't even like the motor i only bought it because my c70 was knackered and i needed a car to get to work, so far I've spent over £200 on a £500 car :( only had it about 3 months.

[Dave86]

Fuel pump or fuel pressure regulator.
Lean mixture can cause misfire under high load.
It would be very helpfull to check fuel trims.
If it's coil pack then fuel trims will be negative cause fuel doesn't get burned and ECU will try to lean the mixture.
If it's low fuel pressure then fuel trims will be positive cause ECU will try to enrich the mixture.
Take the spark plugs out.
If they are covered in dark smokes that means there is problem with the ignition.

Will check the fuel trims tomorrow. when i took the old plugs out on Sunday they were a very light brown.

[merc85]

Would that throw a code at all?

nope

[fassi1]

Will check the fuel trims tomorrow. when i took the old plugs out on Sunday they were a very light brown.

Keep an eye on oxygen sensor voltage too, if it's standard 0-1V then about 0.1-0.2V is lean and 0.8-0.9V is rich.

[960kg]

Bit annoyed at having to spend money on it really as i don't even like the motor i only bought it because my c70 was knackered and i needed a car to get to work, so far I've spent over £200 on a £500 car :( only had it about 3 months.

I understand where your coming from, but owners only usually sell there motors because there is something wrong with them and the buyer picks up the problems.

As you have the OBD11 socket onboard it is wise to spend about £20 on a code reader which will read and erase the error codes.

When you read the codes and if you have any they will then point you to the area where the problem is.

Guessing does cost a fortune before you hit on the cause.

[mitchyboy01]

If you have an android phone, download the torque app £2.95 and get a bluetooth reader on ebay £10. You plug the bluetooth into your ECU and using your phone you get ALL and I mean ALL of the realtime data from the ECU. You can read and clear codes and it tells you what the codes are. You can also datalog voltages, ignition timing etc etc. It's the best thing i've ever had on my phone, saves a fortune in guesswork.

[fassi1]

If you have an android phone, download the torque app £2.95 and get a bluetooth reader on ebay £10. You plug the bluetooth into your ECU and using your phone you get ALL and I mean ALL of the realtime data from the ECU. You can read and clear codes and it tells you what the codes are. You can also datalog voltages, ignition timing etc etc. It's the best thing i've ever had on my phone, saves a fortune in guesswork.
Does it work on all the phase 2 OBDII volvos?
That sounds really good.

[Dave86]

Already got a Bluetooth obd2 reader and torque on my phone there are no fault codes and the engine management light isnt on

[mitchyboy01]

Does it work on all the phase 2 OBDII volvos?
That sounds really good.

Yes mate, works on my P1.5 which has phase 2 software. It really is a great app. If you download it and flick through the screens you will see how good it is. My bluetooth cost £10 and works a treat. I'll find you a link mate. Torque gives everything from MAF airflow, timing advance, revs, Coolant temp, boost, intake temp etc etc. I love it.

[mitchyboy01]

Here you go

http://www.ebay.co.uk/itm/270882753932?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

[fassi1]

What is the long term fuel trim?

[fassi1]

Yes mate, works on my P1.5 which has phase 2 software. It really is a great app. If you download it and flick through the screens you will see how good it is. My bluetooth cost £10 and works a treat. I'll find you a link mate. Torque gives everything from MAF airflow, timing advance, revs, Coolant temp, boost, intake temp etc etc. I love it.
Sounds wicked
I always use diagnostic tools while tunning up the lpg systems and always carry with me scanner with interface cable and other stuff.
That will make tunning up much easier.

[mitchyboy01]

What is the long term fuel trim?

I wasn't sure mate so googled it lol here you go

The short term fuel trim (STFT) refers to immediate changes in fuel occurring several times per second. The long term fuel trims (LTFT) are driven by the short term fuel trims. LTFT refers to changes in STFT but averaged over a longer period of time. A negative fuel trim percentage indicates a taking away of fuel while a positive percentage indicates an adding of fuel.

[fassi1]

I wasn't sure mate so googled it lol here you go

That was question to Dave86 regarding to his issue.

[mitchyboy01]

That was question to Dave86 regarding to his issue.

Oh sorry LOL at least I know now!

[960kg]

If you have an android phone, download the torque app £2.95 and get a bluetooth reader on ebay £10. You plug the bluetooth into your ECU and using your phone you get ALL and I mean ALL of the realtime data from the ECU. You can read and clear codes and it tells you what the codes are. You can also datalog voltages, ignition timing etc etc. It's the best thing i've ever had on my phone, saves a fortune in guesswork.

Hello Mitch,
That sounds very interesting, but i am a thick plank with phones!
Would this work with a 3gs iphone or my top of the range Garmin satnav i have it, does bluetooth and all that stuff??

Keith

[Dave86]

What is the long term fuel trim?

Going to check after work also going to datalog the o2 sensors etc on the journey home

[mitchyboy01]

Hello Mitch,
That sounds very interesting, but i am a thick plank with phones!
Would this work with a 3gs iphone or my top of the range Garmin satnav i have it, does bluetooth and all that stuff??

Keith

Hi keith, the app will only work with the android software version 2.1 or above i think. The Iphone will not support the app.

[Dave86]

According to the torque app this is whats going on when the car is misfiring phones a bit slow when logging but the 4 entries during the misfires are as follows:

Rpm: 2588
Boost Pressure (BAR): -0.4
Engine Load: 21.18 %
STFT: -7.03 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 2988
Boost Pressure (BAR): -0.04
Engine Load: 53.73 %
STFT: 3.12 %
LTFT: -8.59 %
O2 1: 0.01 V
O2 2: 0.03 V

Rpm: 4134
Boost Pressure (BAR): -0.35
Engine Load: 75.69 %
STFT: 0 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 4185
Boost Pressure (BAR): +1.07
Engine Load: 85.88 %
STFT: 0 %
LTFT: -8.59%
O2 1: 0.01 V
O2 2: 0.02 V

By the time i got home the LTFT had changed to -7.81 %

Cant guarantee the accuracy of this as it is just a cheap adaptor and a phone.
The misfire seems to be getting worse and more importantly when the misfire occurs the car STINKS of petrol

[mitchyboy01]

According to the torque app this is whats going on when the car is misfiring phones a bit slow when logging but the 4 entries during the misfires are as follows:

Rpm: 2588
Boost Pressure (BAR): -0.4
Engine Load: 21.18 %
STFT: -7.03 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 2988
Boost Pressure (BAR): -0.04
Engine Load: 53.73 %
STFT: 3.12 %
LTFT: -8.59 %
O2 1: 0.01 V
O2 2: 0.03 V

Rpm: 4134
Boost Pressure (BAR): -0.35
Engine Load: 75.69 %
STFT: 0 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 4185
Boost Pressure (BAR): +1.07
Engine Load: 85.88 %
STFT: 0 %
LTFT: -8.59%
O2 1: 0.01 V
O2 2: 0.02 V

By the time i got home the LTFT had changed to -7.81 %

Cant guarantee the accuracy of this as it is just a cheap adaptor and a phone.
The misfire seems to be getting worse and more importantly when the misfire occurs the car STINKS of petrol

I don't know anything about fuel trim really (need to research) but I can say that if your car is a phase 1 using only a MAF then the boost values will likely be inaccurate as they will only be a calculation of airflow vs rpms. If you use a map sensor it will obviously be spot on.

[Haizum74]

I don't know anything about fuel trim really (need to research) but I can say that if your car is a phase 1 using only a MAF then the boost values will likely be inaccurate as they will only be a calculation of airflow vs rpms. If you use a map sensor it will obviously be spot on.

The torque app has a boost calculation setting in it to select MAP, MAF or ALT. default is on MAP. If that means out lol

[fassi1]

O2 1 is before cat and O2 2 will b after cat.
Both look like is lean but LTFT -8.59% looks like ECU is trying to lean the mixture as it was too rich and u saying that u can smell petrol.
O2 sensor is monitoring 4 cylinders all together, not individually so if its misfiring on 1 or on 2, the ECU will be trying to lean the mixture on all 4 cylinders cause it doesnt know which one is running rich.
If i was u i would take the spurk plugs out and compare them all.
Some will definitely be darker then the others and that will be the one which is missfiring.
To make sure that the MAF is not faulty to the test while driving rev it up to the red line and MAF reading should be aboout 80% of engines bhp which means: 200bhp engine will give max MAF reading about 80% of 200 is 160g/s.
If its a lot less that means MAF is not working correctly.


According to the torque app this is whats going on when the car is misfiring phones a bit slow when logging but the 4 entries during the misfires are as follows:

Rpm: 2588
Boost Pressure (BAR): -0.4
Engine Load: 21.18 %
STFT: -7.03 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 2988
Boost Pressure (BAR): -0.04
Engine Load: 53.73 %
STFT: 3.12 %
LTFT: -8.59 %
O2 1: 0.01 V
O2 2: 0.03 V

Rpm: 4134
Boost Pressure (BAR): -0.35
Engine Load: 75.69 %
STFT: 0 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 4185
Boost Pressure (BAR): +1.07
Engine Load: 85.88 %
STFT: 0 %
LTFT: -8.59%
O2 1: 0.01 V
O2 2: 0.02 V

By the time i got home the LTFT had changed to -7.81 %

Cant guarantee the accuracy of this as it is just a cheap adaptor and a phone.
The misfire seems to be getting worse and more importantly when the misfire occurs the car STINKS of petrol

[mitchyboy01]

Did you relace the coilpacks in the end?

[Dave86]

Did you relace the coilpacks in the end?

Going into gsf in exeter tomorrow to get them

[Neilly]

According to the torque app this is whats going on when the car is misfiring phones a bit slow when logging but the 4 entries during the misfires are as follows:

Rpm: 2588
Boost Pressure (BAR): -0.4
Engine Load: 21.18 %
STFT: -7.03 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 2988
Boost Pressure (BAR): -0.04
Engine Load: 53.73 %
STFT: 3.12 %
LTFT: -8.59 %
O2 1: 0.01 V
O2 2: 0.03 V

Rpm: 4134
Boost Pressure (BAR): -0.35
Engine Load: 75.69 %
STFT: 0 %
LTFT: -8.59 %
O2 1: 0.04 V
O2 2: 0.05 V

Rpm: 4185
Boost Pressure (BAR): +1.07
Engine Load: 85.88 %
STFT: 0 %
LTFT: -8.59%
O2 1: 0.01 V
O2 2: 0.02 V

By the time i got home the LTFT had changed to -7.81 %

Cant guarantee the accuracy of this as it is just a cheap adaptor and a phone.
The misfire seems to be getting worse and more importantly when the misfire occurs the car STINKS of petrol

I had the same symptoms a few months back.....when i took my plugs out there was nothing left of them....one diode on one was practically missing...Put new genuine plugs in and was sorted after that.....does sound like an ignition problem with yours somewhere.....process of elimination maybe for you.....which is annoying and expensive!!

[Dave86]

Got a set of genuine plugs and low and behold problem solved.
I know i was told repeatedly got get some genuine ones and ignored it lol I've learnt my lesson.

Thanks everyone for all your advice (even if i didn't listen)
Roll on sunday so i can smash it down the strip :)

[960kg]

Got a set of genuine plugs and low and behold problem solved.
I know i was told repeatedly got get some genuine ones and ignored it lol I've learnt my lesson.

Thanks everyone for all your advice (even if i didn't listen)
Roll on sunday so i can smash it down the strip :)

As said in my previous post......a T4 misfiring on boost is nearly always ignition, in fact most turbo motors.....why the T4 is fussy on plugs who know`s but now you can believe it, first hand experience, but others never ever believe it.

Glad your sorted.

[Haizum74]

As said in my previous post......a T4 misfiring on boost is nearly always ignition, in fact most turbo motors.....why the T4 is fussy on plugs who know`s but now you can believe it, first hand experience, but others never ever believe it.

Glad your sorted.

Got to agree with you. Mine did it on my last one and after consultation with folk on here, I bought volvo sparks. No more issues (well until the turbo went lol)

[JamesT5]

Misfiring! Oh, have you read my V70 P23 misfire threads? It turns out I had dodgy coil packs, changed them and now it's fine. Get a code reader off ebay (OBD2) and read your codes. My bet is P0300 or P0301, P0302, P0303, P0304 or P0305 for a 5 cylinder engine. If it is, change your coil packs, they're a ruddy nightmare!

Regards

James