i've noticed since owning this new zed, acceleration is far better than the uk spec one i've got (even with stage 1 fitted to that) but i have noticed during decelleration i'm getting popping through the exhaust it's quite regular (every 2 or 3 seconds) just wondering what could be causing this? the car is decatted so no issues with blowing holes in cats etc but i am a little worried about engine damage issues

sounds like its over fueling slighty

funnt you should say that if i leave the car to tickover for over 10mins ish the exhaust fumes start to smell very rich blip the throttle couple of times and it clears and all is fine again, i'm wondering if maybe o2 sensors need changing?

mine also does this too?

Agree with car.mad

What would cause this? could it be anything to do with my mines ecu? (sorry for the thread hijack)

Yeah it could be the mapping. O2 sensors, boost leak etc

well i've got a vac hose kit on order so hopefully if there are any boost leaks hopefully i'll find them might be a idea to lift ecu to see if i can find what chip is in there, i'm gussing with boost increase etc it must of been mapped at some point

It could be a failing coil pack or bad connection to one. It could also be an air leak on the exhaust side.

get some contact cleaner and spend a couple of hours cleaning every connector you can get to in the engine bay

get some contact cleaner and spend a couple of hours cleaning every connector you can get to in the engine bay

 

already done quite a few of them, coil pack connectors have been replaced, i'm wondering if timing has been adjusted

Mine does this big time no wonder on 3-5 mpg

do the MAF, PTU and CAS connectors too ;)

cheers vijay looks my work for sunday morn then lol

It's your ECU most likely, too rich a fuel map for the power you're putting out = unburnt fuel and inefficient running = pops and bangs

Its definitely likely to be Unburnt fuel exploding in the hot cylinders, timings to retarded either on the engine or the ecu. Either that or you have a mild air leak or a tired Landa sensor that's nit monitoring mixtures efficiently

Check the static timing of the engine first to ensure it's not too retarded

It is quite possible that whoever had it mapped actually wanted a bit of popping and cracking on the overun. My mate had his caterham tuned like that - doesn't improve performance but does sound pretty cool if you like that sort of thing..

 

I would get the map checked out and or tweaked - if everything seems to be working fine then its probably just a fuelling issue. I'd keep it like that:thumbup1:

well i've prgressed no further with this and the problem is still present i have so far replaced every vac pipe under the bonnet check connectors etc but here is the funny part it is only doing it if revs are below 2000rpm but not all the time now i did find a loose injector connector which has been causing a slight misfire every now and then so next course of action is replacing all the injector connectors

Is it actually a problem?

 

Have you tried revving the engine when its hot (preferably in a bridge or tunnel) at night to see if its spitting flames? I'd hope so!

 

I wouldn't start replacing lots of stuff though - unless you want to.. Better to get a proper diagnosis done.

 

"Look, there's a wild goose - lets chase it" and so on:lol:

Leo

the person that tuned it should know to advise their client/friend/customer that excess unburnt fuel and popping n cracking is of no gain and simply a waste of fuel and no good for the engine.

 

Fouls plugs

Wears valves

Generates uncessary combustion chamber pressures

raises exhaust gas temperatures and simply speeds up engine wear therefore reducing the life of piston valves as well as coking up the chambers and valves and piston crowns with solid carbon (which also increased the chances of detonation)

 

If they want anti lag then fit a proper management system and set the engine up accordingly :)

 

 

 

Black Zed

 

have you had a timing light on the engine and done the basics dude ???

 

If it only does it below 2k then it could be that the CAS needs checking/adjusting to suit the timing values programmed on whatever chip it is..

 

So long as it doesnt do it consistently all the time then it shouldnt be too much of a bother

 

Loose injector connectors?? definitely get those sorted.. ive seen one or two engines kill a piston due to connectors just shoved on :(

 

could even be a weak coil pack not firing 100%

 

there old cars at the end of the day really

well yes i did have a strange misfire problem on cylinder 6 a while back (which is the one with the dodgy injector connector) found it to be misfiring so i swapped coil packs with a working cylinder, misfire was still present on same cylinder i then swapped plugs and between both cylinders and it cured it was really strange made me thibk it may also be ptu problem as i've still got a series 1 ptu on the car at moment

You tried swapping an injector ?

I like the popping and bangs!

You tried swapping an injector ?

 

not yet as injector seems fine when i was getting the misfire it was related to injector conector as it came off partially cause the metal clip is not latching on

sounds like the over run fuel cut has been disabled to me, nothing sinister.