Richie15

Hi all this issue seems to have got worse since the cars been off the road to fit new gearbox,
The problem is when it's first fired up it doesn't like to be revved, it sounds as if it's running on 3 cylinders it's quite rough and pops and bangs if revved and is spluttery and hesitant, however...if I take it for a drive and get it to boost up it cures the problem and it will rev smooth and responsive from then on!?

The engine is a 2.0 silvertop Zetec E (late model)
Fully rebuild with forged pistons rods ect
Focus Rs turbo running 1 bar direct atm
EFI HO inlet manifold
omex 600 ecu
3bar map sensor
New coilpack, leads, plugs,
New ICV
haven't yet tried tps
New coolant temp sensor
Omex air temp sensor

I will be doing a compression test once I get my hands on a gauge

The engine since I've built it is still on a running in map untill I covered 1000 miles and has always had a hunting on idle (the mapper said he couldn't work out what was causing it but it was mapping and running fine other than that) I cannot eliminate this I'm hoping that once remapped (from a cold start) it will cure this, as the engine was hot by the time he got it running nice.

Any help/advice will be much appreciated, thanks.

t230

i had this with incorrect MAP sensor or may be unplugged or pipe work may be leaking ......i also had it 'as if ' itt were running on 3 cylinders becuase of a torx bit having been dropped in oil filler capped thus smashing straight thru head...for sum reason gave me 3 cylinder effect


jus go over and double check everything

studabear

have you got a afr gauge fitted?

Richie15

Sorry but what's an afr gauge ?

I've checked everything to do with map sensor plug is fine vaccum is fine no air leaks at all
Really getting to me now lol
Cheers for the help

studabear

Air fuel ratio, you need a wideband lambda sensor in the exhaust too

Richie15

No haven't got one of them fitted, it was mapped with a wideband fitted then taken off afterwards as it was the guys who mapped it he didn't say I needed to re fit one I'll invest in one of those for the remap for sure

Churtz

Compression test first. From cold then hot. See what's changing. Sounds like somethings not right there to me.

stevieturbo

Whilst it may be partly mechanical, just sounds like a mapping issue for the most part.

And put new plugs in it.

Churtz

I hear what you're saying about mapping, but mapping wouldn't have got worse since it's been off the road.

stevieturbo

yes, but you also said it is still a running in map, you never gave how much history as to when it ran perfectly for.

You said it had been laid up, and possibly now with some short start stop scenarios which could lead to plugs either flooding or fouling if the cold start wasnt great. Which in turn could lead to it going off cylinders.

Hence...get mapping checked, and fit new plugs.

yes there may be other issues...but without some ecu information in front of me, or the car in front of me....rather difficult to diagnose.

Richie15

Thanks for the help, I will be taking it for mapping soon as it's on the road just didn't want to take it there to be mapped an fine out something's up that I could have fixed beforehand
Thanks