Misfire

stevengude · Post by **stevengude** » Wed Dec 28, 2016 3:27 pm

: Screenshot_2016-12-28-14-18-13.png (271.63 KiB) Viewed 1054 times

As soon as something is fixed, another thing breaks...

Ive bought an obd2 connector on ebay and used torque pro to read my fault codes . Ive attached the screen shot of the report.

Any ideas on how to fix these?

Chris_D · Post by **Chris_D** » Wed Dec 28, 2016 3:57 pm

wow. middle cylinder on each bank.
did it happen at the same time?
plugs and coils out for inspection and/or replacement I think.
If they both went at same time it makes me think it might be something further upstream - vac leak, fuel pump etc.
battery in good condition?

edit: oh no, not middle cylinder. duuh.

stevengude · Post by **stevengude** » Wed Dec 28, 2016 4:15 pm

Chris_D wrote:wow. middle cylinder on each bank.
did it happen at the same time?
plugs and coils out for inspection and/or replacement I think.
If they both went at same time it makes me think it might be something further upstream - vac leak, fuel pump etc.
battery in good condition?

Torque pro does tell me when they happened just that they happened. Ive cleared them and ill see if them come back when i drive it tomorrow.

Battery is fine, was checked a few weeks ago when my starter motor packed in

Chris_D · Post by **Chris_D** » Wed Dec 28, 2016 5:30 pm

stevengude wrote:
Chris_D wrote:wow. middle cylinder on each bank.
did it happen at the same time?
plugs and coils out for inspection and/or replacement I think.
If they both went at same time it makes me think it might be something further upstream - vac leak, fuel pump etc.
battery in good condition?
Torque pro does tell me when they happened just that they happened. Ive cleared them and ill see if them come back when i drive it tomorrow.

Battery is fine, was checked a few weeks ago when my starter motor packed in

think ur first port of call is to get the plugs out, all of them, to see what condition theyre in. if theyre 50k miles then replace maybe. if not, a good clean with a soft wire brush with some carb cleaner or contact spray could solve ur problem. is ur eml light coming on?
further to that i'd invest in new coils (bosch only) theyre about a tenner each to do a cancelling-out test. if ur feeling sufficiently gung-ho then replacing the plugs and coils may be ur first step in cancelling out the problem.
further to that it's going to take a bit of diagnosis.
if the misfire is pretty bad i'd suggest not driving too much as unburnt fuel can damage the cats.
good luck and keep us posted re progress....

stevengude · Post by **stevengude** » Wed Dec 28, 2016 11:27 pm

Chris_D wrote:
stevengude wrote:
Chris_D wrote:wow. middle cylinder on each bank.
did it happen at the same time?
plugs and coils out for inspection and/or replacement I think.
If they both went at same time it makes me think it might be something further upstream - vac leak, fuel pump etc.
battery in good condition?
Torque pro does tell me when they happened just that they happened. Ive cleared them and ill see if them come back when i drive it tomorrow.

Battery is fine, was checked a few weeks ago when my starter motor packed in
think ur first port of call is to get the plugs out, all of them, to see what condition theyre in. if theyre 50k miles then replace maybe. if not, a good clean with a soft wire brush with some carb cleaner or contact spray could solve ur problem. is ur eml light coming on?
further to that i'd invest in new coils (bosch only) theyre about a tenner each to do a cancelling-out test. if ur feeling sufficiently gung-ho then replacing the plugs and coils may be ur first step in cancelling out the problem.
further to that it's going to take a bit of diagnosis.
if the misfire is pretty bad i'd suggest not driving too much as unburnt fuel can damage the cats.
good luck and keep us posted re progress....

My eml light isnt coming on no

Ill look at the plugs tomorrow and update

VRSteve · Post by **VRSteve** » Thu Dec 29, 2016 12:08 am

Vac leak won't cause a misfire unless its over all cylinders.
Fuel pump won't cause a misfire unless its over all cylinders.
A misfire error code would normally be a spark failure. The ECU in the older cars would not be bright enough to know that a misfire has occurred for any other reason. Obviously with newer injector technology that has changed on newer cars, but that isn't relevant here.

The rest of the advice is good, plugs, coils, check connections on the coils etc etc.

In fairness they may well be old codes, and if the engine was missing, I dare say you'd know about it.

Don't worry about it unless it actually comes back!

Scooba_Steve · Post by **Scooba_Steve** » Thu Dec 29, 2016 11:18 pm

I would move one of those coil packs to another cylinder and see if the fault follows. That's an easier first step than plugs, but would assume it's either/or both. You could replace all the sparks and then coils if needed.

stevengude · Post by **stevengude** » Tue Jan 03, 2017 9:45 pm

Just a quick update.

I got in the car to go to work this morning and it sounded horrific. I took our lass's car to work and andy kindly came and looked at the car tonight and i had flooded the engine with fuel when just turning it on for a brief moment - a couple of monents later it was solved. Not misfiring but still reading misfire codes on torque pro.

Booked in with Andy on Thursday to look at coils and plugs and try and fix an oil leak (will upload picture tomorrow of the oil).

Will keep you all updated

andyfanshawe · Post by **andyfanshawe** » Wed Jan 04, 2017 12:14 am

Chris_D wrote:
stevengude wrote:
Chris_D wrote:wow. middle cylinder on each bank.
did it happen at the same time?
plugs and coils out for inspection and/or replacement I think.
If they both went at same time it makes me think it might be something further upstream - vac leak, fuel pump etc.
battery in good condition?
Torque pro does tell me when they happened just that they happened. Ive cleared them and ill see if them come back when i drive it tomorrow.

Battery is fine, was checked a few weeks ago when my starter motor packed in
think ur first port of call is to get the plugs out, all of them, to see what condition theyre in. if theyre 50k miles then replace maybe. if not, a good clean with a soft wire brush with some carb cleaner or contact spray could solve ur problem. is ur eml light coming on?
further to that i'd invest in new coils (bosch only) theyre about a tenner each to do a cancelling-out test. if ur feeling sufficiently gung-ho then replacing the plugs and coils may be ur first step in cancelling out the problem.
further to that it's going to take a bit of diagnosis.
if the misfire is pretty bad i'd suggest not driving too much as unburnt fuel can damage the cats.
good luck and keep us posted re progress....

4

All good ideas, BUT...not gonna do swaptronics here. Modern day diagnostics isn't about swapping parts, its about proving 100% they are not working properly.
Oscilloscope current ramp waveform on each coil first.
Same on each injector. Possible injector flow test.
Running relative compression test via scope on the engine also, to rule out mechanical issues.
Definitely a spark plug check though by the old fashioned removal method LOL!

Interestingly fuel trim on both banks was perfect, pre CAT O2 sensors were switching fast and well, post CAT sensors were reading a good solid 0.7 volts. So no CAT damage there.

No doubt Steven will keep you all informed on thursday how all the tests went. I'll certainly enjoy doing them!

Andy.

stevengude · Post by **stevengude** » Thu Jan 05, 2017 10:04 pm

Andy will be able to offer a more technical view than me, but in summary..

We took the car for a drive with the scanner plugged in, and everything looked fine.

Took the car back to andys workshop. All plugs and coils came out and were inspected, and all looked fine.

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Some more tests were run and all coils passed with flying colours. Fuel line checked and all fine.

Then on to trying to find a suspected oil leak. On tuesday we spotten a lot of smoke and some liquid on a pipe below the engine. However today when we got the car in the air we couldnt find a single spot of oil anywhere. Maybe it was just having a bad day on tuesday

Rest of car was checked and no problems found.

Putting the misfire down to a split lower intake boot, part ordered for £26 and in going to try and fit on saturday before inevitably failing and giving it andy to do.

stevengude · Post by **stevengude** » Sat Jan 07, 2017 5:14 pm

Further update

After a lot of swearing ive fitted the new intake boot this morning, also changed air filter.

This was the old part

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Also took my washer fluid tank out and cleaned the filters. Amazed how much crap was in there!

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Chris_D · Post by **Chris_D** » Sat Jan 07, 2017 5:19 pm

Why a 'lot of swearing' re the intake boot? Its not such a difficult job. You could have gone a bit further and taken the throttle body out to de-varnish the flap and the icv to de-carbonize it. Worthwhile jobs if theyve never been done, seeing as you were in the vicinity of them.
Any improvements to the misfire after replacing?

stevengude · Post by **stevengude** » Sat Jan 07, 2017 5:49 pm

Chris_D wrote:Why a 'lot of swearing' re the intake boot? Its not such a difficult job. You could have gone a bit further and taken the throttle body out to de-varnish the flap and the icv to de-carbonize it. Worthwhile jobs if theyve never been done, seeing as you were in the vicinity of them.
Any improvements to the misfire after replacing?

Not a difficult job no, but very fiddly when you have big hands trying to get to the little screws (and im a complete novice).

I think its fixed it, no codes at the moment ill check again tomorrow after a 30min run

z4all · Post by **z4all** » Wed Jan 11, 2017 9:47 pm

Well done mate. Love a goo diy success story

stevengude · Post by **stevengude** » Wed Jan 11, 2017 10:44 pm

z4all wrote:Well done mate. Love a goo diy success story

Thanks

The car is running fine now, a joy to drive

thanks for everyones advice

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