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Discussion Starter #1
I have a 1.6 16V (X16XE) in my nova, mods are performance inlet manifold like mantzel power box, enlarged throttle body, superchip, cone filter, powerflow manifold back exhaust, EGR and secondary air injection stuff removed and blanked off.
It seems to be overfueling, I think im using far too much fuel, also the exhausts are really black and the spark plugs are also pretty black (carbon not oil). and doesnt seem as quick as it should be as I could only get 17.01 on the 1/4 mile today.
There are no ecu fault codes stored so nothing obvious wrong, ive changed the lambda sensor and CTS for spares and its no different (although the ones ive fitted are only scrap yard spares so they could be faulty but unlikly). Also recently changed the spark plugs and HT leads.
It seems to smoke a little when you rev it high when stood still, but the smoke is only greyish, so overfueling?

any suggestions or things I could try to sort it?
 

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Get rid of the superchip, they can be a bit rough!

They have been likend to randomly adjusting screws on a carb and hoping it will run better

You may get an improvement, but most likely you will just throw everything out!!
 

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didnt phil have a selection of chips might be worth changing that
 

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Mine was doing exactly the same!
I found 2 air leaks on the mantzel/inlet manifold and the air inlet pipe.
Have a look.
 

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Discussion Starter #5
Will have a good look at all my vacume pipes & check for leaks. I'll also try out the other chips. Got a total of 3, the other two have never been tested out. If there is no change i'll put the standard one back in ad see how it is.

What kind of time sould this engine be getting on 1/4 mile?
 

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Discussion Starter #6
I cant find any vacume leaks. I will be tryin the other chips on the weekend.

If the problem is over fueling (I do seem to go through alot of feul) what can cause it besides the CTS abd Lambda sensor?
 

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Does it idle OK?
Try swapping the MAP sensor.
Should be aiming for about 15.5, depending on weight etc.
 

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Discussion Starter #9
Foy Bacer said:
Does it idle OK?
Try swapping the MAP sensor.
Should be aiming for about 15.5, depending on weight etc.
the car idles ok, about 850RPM. The idle speed can be a bit lumpy sometimes.

With the mods i have i was hoping for around the low 16s for the 1/4 mile.


I will be having a mess around with it on the weekend and see what happens.
 

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Paul got another throttel housing here with a modded buterfly and all the sensors if you wanna try a swap
 

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Mate in my BOG standard Nova GTE full weight etc got a 16.1

So I would aim a little higher ;)
 

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Discussion Starter #12
assassin said:
Paul got another throttel housing here with a modded buterfly and all the sensors if you wanna try a swap
I'm ok, I've got some spares i can try, thanks
 

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Discussion Starter #13
ive swapped for new my cts and 02 sensor, ive changed the dispack, MAP sensor and air temp sensor for spares and ive put my standard chip back in the ecu.

the car is defiantly faster, but still hesitates a bit after the engine has warmed up. i still think its overfueling. what else could i try. Im gonna check all electrical connections on weekend.

whats the best way to check for a vacume leak?
 

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Maybe I havent read it properly but what about your fuel pressure? I noticed the pics were done in Stockport, I live there! If you want to try swapping any parts from my Corsa GSI then feel free, just drop us a PM!
 

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dont supppose the homemade powerbox could be throwing toys out of the pram?? air leaks prehaps?? check inlet manifold gasket??
 
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