remap issue or just coincidence?? misfiring :(

[kb86]

Hey all

had my car remapped about 5 week back, then couple of week back I installed an additional air feed to the airbox.

last two days cars been misfiring (scanned and it's multiple ports)

Replaced the coil packs and sparks today but no joy.

There is heat corrosion on the leads that go to the coil packs, which i'll need to sort out and I believe there is a valve hidden away under the inlet manifold i need to check too.

The guy that did the remap is away at the mo so can't ask him, But does anyone think this could be the issue? or have any other suggestions regarding what I can check to get it sorted.

I'm driving the mother-in-law's punto whilst this gets sorted (So you'll understand the urgency lol)

audi A4 B6 1.8T

cheers

kb

 

[Darran]

Can you post scan ?

 

[Mike.M]

You have done the obvious but a VCDS scan would be best before going any further

 

[adamss24]

Check coils, they known to blow after remap and will do exactly what you describe...

 

[kb86]

cheers for the suggestions, Brand new coils and spark plugs fitted (not the budget one's either)

cleared the faults using ODB reader before leaving my garage, picked up misfire on, 1, 2 & 4 & separate reading stated multiple random misfires.

no mention of anything to do with air flow etc.

however, just been out to test it again & take a screen shot to post on here and there are no recorded faults (despite the engine light flashing multiple times on the way home) & it's clearly still misfiring

hope that helps

cheers

kb

 

[Darran]

Has it had a cambelt very recently ? Also not all obd readers will interrogate the ecu's deep enough which reader you using.

 

[Paul @ Unit 9 Remaps]

most likely MAF weak

 

[kb86]

new engine was put in it about a year ago now, at which point it had new belts, clutch etc fitted, all the things you'd sensibly do whilst the engine is out of the car.

funny story about the MAF sensor, car broke down so I called the AA, they removed power lead to the MAF & hey presto, car worked again (albeit hardly any power). So went off and got brand new MAF from TPS (Leeds) £90 odd quid. Fit it & still no change. then realised one of the pipes to the FMIC had blown off. FAIL!!

school boy error but to answer your Q, the Maf is about 8 months old and the belts about a year.

may check out the tensioners though (however these we're all part of the pack when belt was done)

Agreed re ODB though, will get a full check done asap

Spoke to Re-map guy, doesn't think changing it back to factory map will sort it. but has advised that poss causes could be N75 valve & boost valve, said if changing them to replace with S3 one's as they're an alloy piston type valve.

not home-worked these yet but seems to know about common probs following remaps so will post any progress

thanks again guys

kb

 

[kb86]

Quick Q, is the boost gauge the same as the diverter valve?

people/ internet are describing the location but all i can find it the DV

please help, cos if this it the case, I'm getting my coat and a torch lol

 

[john777w]

You don't have a boost gauge, unless you've fitted a aftermarket gauge!
The diverter valve is also know as the dump valve

 

[kb86]

You don't have a boost gauge, unless you've fitted a aftermarket gauge!
The diverter valve is also know as the dump valve

Boost valve sorry, not boost gauge.

the guy that did the remap said about checking N75 valve & boost valve.

reason I ask is, I fitted an after market DV which you could alter from soft to hard. wondering if this could be the issue?

when you google "boost valve" Or Diverter Valve" the results are pretty much identical.

any ideas?

 

[kb86]

right it's sorted

gunna start a thread an link as lot's to take into account

will link on next thread but please throw in your own comments and experiances

 

[kb86]

as promised, problem solved, hope it helps someone

http://www.audi-sport.net/xf/threads/audi-a4-b6-misfire-rough-idle-advice.240006/