101 replies to this topic

[NickB787]

great news you found part of the trouble

[DaveyC]

Two new oxygen sensors ordered. Hopefully these fix the running issue.

[DaveyC]

New sensors installed. The main sensor has been replaced with a genuine part and the second sensor has been replaced with an aftermarket one.

 

Misfires still present.

 

If I blip the throttle from idle, the engine stalls.

 

In neutral, gently bringing the revs up I can feel the misfires constantly between 1500 and 2500rpm consistently.

[techieboy]

Collapsed cat blocking the exhaust?

[DaveyC]

I had a snake camera in there while the sensors were out and it looked intact.

[NickB787]

I had a snake camera in there while the sensors were out and it looked intact.

mine looked ok wasn't until the pipe was off that I realised it was sliding up and down as the welding had gone.

[DaveyC]

Could you hear any noise from it moving? Mine's got a tinny rattle from the resonance at very low revs, but I think that's just the heat shield which doesn't fit perfectly with the aftermarket exhaust.

[Steve.i.am]

Probably not the same issue, but mine stuttered and sometimes stalled on blipped throttle and it was the MAP sensor. I see you've had a new TMAP so its probably not that but thought it worth a mention.

[CHILL Gone DUTCH]

Mine also lost its locating welds causing the cat to rattle around

[vocky]

cheap pattern map sensors cause serious problems, you should only use genuine map sensors 

[DaveyC]

cheap pattern map sensors cause serious problems, you should only use genuine map sensors 

 

TMAP is genuine Bosch

 

I only used a cheap sensor for the post-cat lambda.

[NickB787]

I have spare Bosch traps here if you want to try? can't get them out till Saturday though am away

[DaveyC]

Peter has tweaked the base map slightly and now the misfire persistence has reduced. The engine no-longer cuts out when the throttle is quickly applied.

 

Still getting the misfires on gentle throttle though.

 

Does anyone with some experience working with OBD tuner fancy a day helping me sort the map out? I'm happy to reimburse you for your time and travel costs.

[Bargi]

Just gone through your thread and - have you tried a new/different coil pack? - is it clean between plugs and coil pack? - what are your plugs gapped to? Try them at .7mm - failing the above check the cam timing? I had lots of stuttering/misfire on Dutch that didn't exist on CS map solved by dropping the plug gap from OEM 1mm to .7mm

[DaveyC]

Just gone through your thread and - have you tried a new/different coil pack? - is it clean between plugs and coil pack? - what are your plugs gapped to? Try them at .7mm - failing the above check the cam timing? I had lots of stuttering/misfire on Dutch that didn't exist on CS map solved by dropping the plug gap from OEM 1mm to .7mm

Thanks for the advice.

 

I haven't tried a different coil pack, but the contacts on the pack and the plugs are both clean.

Plugs were gapped to 1mm but I set them to .7mm a week ago, there was no difference to the way the engine ran.

I haven't checked the cam timing - it looks like I may have to even though I installed everything to the correct timing marks it is possible the cams were manufactured slightly out. Although, the old engine also misfired and that was running standard internals with a timing chain installed by Vocky not many miles before it came into my possession.

 

I'll see if I can borrow a coil pack from someone to rule that out.

[vocky]

I remember your car now, both chains done with genuine parts and the balancer delete on the replacement engine.

 

Try a coilpack 

Edited by vocky, 26 March 2015 - 08:26 AM.

[oakmere]

Don't get a cheap e-bay coil pack. Get GM or a Denso.

[Exmantaa]

What cams are in?

 

Some of the ZZP Comp's had base circle issues that causes misfires and idle issues. But your's is idling OK @ ~800rpm, right?

Maybe post an idle log so we can see where it misfires?

[DaveyC]

What cams are in?

 

Some of the ZZP Comp's had base circle issues that causes misfires and idle issues. But your's is idling OK @ ~800rpm, right?

Maybe post an idle log so we can see where it misfires?

 

They're Comp Cams Blower cams.

 

It idles OK.

 

I'll dig out a log when I get home. I'm not sure how you spot the misfires in the log since the 'misfires' data in the logs never records any even when they can be felt whilst driving.

[DaveyC]

https://drive.google...iew?usp=sharing

 

This is a log of the engine idling and then me blipping the throttle to try to replicate the cutting out.

 

I've not got OBD Tuner on this PC so I can't see if I did any low rev stuff on there, but if there is any at all held around 2000rpm for any amount of time then it will have been misfiring.