Running lean - need advice


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GreedoUK

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Hi guys since having a j's style intake and new exhaust header installed my engine has been running lean in the low revs, as in you put your foot down and it just wont go, it gets noisier, but no power, then all of a sudden it will just go and i'll fire off like something been pulling back on me then let go! then it will all be fine in the high rev's.

its getting a bit annoying so i took it to a garage and they told me im running lean due to the extra air flow my stock 02 sensor cant read it properly

what do you guys suggest I do? he mentioned getting a wideband o2 sensor and he can do it, or getting the car re-mapped at a tuners somewhere nd of course just putting it back to standard.

does this sound right and where would you guys recommend getting whatever's needed from?

thanks in advance!
 
Shouldn't have the issue from that pal. I'm running a couple more bits than that and it runs alreet.

Sounds like you may have another issue. You say it gets nosier, are the revs rising? Assume they are. As a freebie try putting it into third at 30 and flooring it see what happens, if revs rise and no pick up your clutch is slipping like a coont! Something to rule out.

Would have thought a mechanic would know this though. You don't need a wideband for that mate, that's for properly fine tuning when mapping.

He is right with mapping though, essentially you SHOULD be mapped for every single mod you install but nobody does!
 
boro_andy said:
Shouldn't have the issue from that pal. I'm running a couple more bits than that and it runs alreet.

Sounds like you may have another issue. You say it gets nosier, are the revs rising? Assume they are. As a freebie try putting it into third at 30 and flooring it see what happens, if revs rise and no pick up your clutch is slipping like a coont! Something to rule out.

Would have thought a mechanic would know this though. You don't need a wideband for that mate, that's for properly fine tuning when mapping.

He is right with mapping though, essentially you SHOULD be mapped for every single mod you install but nobody does!
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nah it's not my clutch, it gets noiser as in the intake noise difference between half and full throttle when you put your foot down, if you keep it at half throttle nothing happens the revs just rise extremely slowly as if you're just resting your foot on the throttle, you need to give it more and more throttle and then it goes, and if you're in 1st or second it just fires off like a rocket lol
 
Changing your Manifold can/will change the way you engine behaves. More than likely running lean. I had issues when i first done the bolt on filter and then my Mugen manifold, the car made good power but ran slightly lean, more lean than some tuners would like to see, however it was a fast one and many people couldn't understand, until i cracked an exhaust valve on no.3

So, get a Wideband on there, so cheap and can save your engine. But won't sort the problem, as for the noise, i would pull the cam cover and check for damaged components.
 
Can you actually get a wideband for less than £200? That's not cheap for something that isn't Finns solve the problem.

So what gears does it do this in? If first does nothing and is normal?
 
Running lean wont make you go slow, most of the time you will go super fast then go bang. Tell them to stop making assumptions and get to the bottom of the problem properly. What most people never understand is that with any type of modifications the tune will need to be adjusted
 
Sorry forgot to make clear, the noise in these 'flatspots' is just the induction noise, as you press your footdown more nd more you can hear the induction getting louder like you should but hardly and increase in revs, then after you get to 3/4 / full throttle it will let go and launch off.

it doesnt do it all the time, but it is very frequent

And it does this in every gear, most noticable 1st and 2nd, but thats probably due to when it does go it flys through the revs quicker and gives you a bigger kick

but it does it in ever gear anywhere between 2k and 4k revs

its also only done it since my manifold's been fitted so it must have something to do with it, too much of a coincidence to not be it, cheers for the suggestions
 
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It sounds like a distributor issue. Or electrical issue of some sort.
Lean will not make it go slow...only pop.
 
i thought flatspots were usually a sign of running lean? i think im going to get it dynoed and get the dizzy looked at
 
Checked your spark plugs? if they`re white that`s a good sign your engine is running lean.
 
GreedoUK said:
i thought flatspots were usually a sign of running lean? i think im going to get it dynoed and get the dizzy looked at
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The thing what has got me thinking is that it should be running lean more towards the top of the powerband and not down low if anything. Either way you need a wideband to check if you actually are running lean. You won't be able to check the plugs unless there new and you know what your looking for.
 
Well i've just got myself an oem manifold again couldnt use my old one as it was split. Thats what started the problem so hopefull this will sort it.
 
Probably not related but what have you done with your IAT sensor? I'm assuming on EK9 they are normally in the intake ducting but if you have one of those whale's willy intakes afaik they don't have a hole for it.
 
clockwoRk said:
Probably not related but what have you done with your IAT sensor? I'm assuming on EK9 they are normally in the intake ducting but if you have one of those whale's willy intakes afaik they don't have a hole for it.
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No mate EK9's IAT is in the manifold itself not in the ducting like a EK4.
Plus 99% of the copy whale's willys do have the hole for the IAT & you have to blank them for EK9's!:secret:
 
I have an EK4, and there is a hole on my whale willy for it and its all in correctly ive checked the intake so thats not the problem either.
 
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