neo2810 Posted January 22, 2011 Share Posted January 22, 2011 Ever since I had the work done on my NA (Tubular manifold, double decat, full new custom performance exhaust, custom performance intake), I've had a slightly stronger smell of petrol while driving at times (inside the car). Does this indicate overfuelling or is it normal? Should I have reset the ECU when the work was done to allow it to relearn the new setup (more air being pulled in, etc) or is that unnecessary? The car runs beautifully so I'd rather not temp fate if it doesn't need doing but logic tells me since the mix has probably changed, maybe the ECU should be allowed to recalc what it needs to be doing? Can the stock NA ECU even be reset? Quote Link to comment Share on other sites More sharing options...
Nic Posted January 22, 2011 Share Posted January 22, 2011 A petrol smell could be due to overfueling, if it is running rich you'll be getting un-burnt fuel dumped into the exhaust. You could try resetting the ECU, it can do no harm, it may run a bit lumpy and want to stall at first but after a few miles should be running right again. If it still smells after the reset then get the AFR's checked at a garage, it could be that the oxygen sensors are worn causing it to run rich. Quote Link to comment Share on other sites More sharing options...
Kirk Posted January 22, 2011 Share Posted January 22, 2011 (edited) Its been common on NA's to overfuel when running a tubular manifold etc but the ecu simply cannot learn how to compensate for the changes so i cant see how ressetting it will make any difference. You need a standalone or piggyback to take full advantage of it. Edited January 22, 2011 by Kirk (see edit history) Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 22, 2011 Share Posted January 22, 2011 (edited) Its interesting that the N/A should respond like this to fitting a tubular manifold and de catted, as the fueling stays in closed loop most of the time, and so would be controlled by lambda feedback, so it seems the ECU doesn't have enough leeway to compensate, which seems daft, so why doesn't the TT have a problem once decatted, since it runs in lambda feedback until hight RPM/load/boost. I'm wondering if there is something else going on here. Edited January 23, 2011 by Tricky-Ricky (see edit history) Quote Link to comment Share on other sites More sharing options...
Shane Posted January 22, 2011 Share Posted January 22, 2011 If as you say the smell is inside the car, then have a look at the fuel pipes around the pump and sender unit under the spare wheel. it's easy to access, just a set of nuts around a black cover that you will see once you pull the spare out. If you can, try and work out if the smell is strongest at the front or the back of the car. Has the charcoal cannister been removed? I don't think resetting the ecu is going to make any difference to be honest, but its easy enough to do and soon re-learns so there would be nothing lost if you wanted to eliminate this. Quote Link to comment Share on other sites More sharing options...
neo2810 Posted January 22, 2011 Author Share Posted January 22, 2011 Thanks chaps, I'll do a bit of investigating before I reset. Shane, good call on the fuel pump, I'll have a nose around tomorrow. I'm not sure where the smell is coming from really, I only get it while driving but I've not actually spent any time idling to see if it's still apparent. Will do that tomorrow and try locate strongest source. The charcoal cannister is probably still there, I've never checked, but may actually be the cause of the rattling in my engine bay so worth a check Quote Link to comment Share on other sites More sharing options...
hodge Posted January 23, 2011 Share Posted January 23, 2011 If you get stuck mate bring it over mine and I'll have a look for you if you want. Quote Link to comment Share on other sites More sharing options...
Ian C Posted January 23, 2011 Share Posted January 23, 2011 Funnily enough we've been discussing this in David's NA project thread. I figure that if you run rich after fitting a 'breathing' modification, you've actually lost power Perhaps it's only at low engine speeds though, due to the headers being tuned for higher rev operation? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 23, 2011 Share Posted January 23, 2011 I agree, but it doesn't make sense that the N/A exhaust system should be so restrictive, as to cause the ECU to fail to be able to compensate once decated and tube manifold fitted? IMO the ECUs closed loop fuel compensation maps would have to be very conservative, not to adapt. Quote Link to comment Share on other sites More sharing options...
Kirk Posted January 23, 2011 Share Posted January 23, 2011 Perhaps it's only at low engine speeds though, due to the headers being tuned for higher rev operation? How does one know the headers have actualy been tuned at all? I highly doubt manufacturers of these headers have actualy designed and tested them with real performance in mind, rather just as a bolt on mod still it doesnt explain why they run so rich. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 23, 2011 Share Posted January 23, 2011 How does one know the headers have actualy been tuned at all? I highly doubt manufacturers of these headers have actualy designed and tested them with real performance in mind, rather just as a bolt on mod still it doesnt explain why they run so rich. They probably where once, just a design that been riped off/copied from another manufacturer, several times around;) Well what Ian is saying about changing the headers making it run rich, so therefore logically the flow is actually worse, and so less power is being made, which i think is quite correct. Quote Link to comment Share on other sites More sharing options...
Kirk Posted January 23, 2011 Share Posted January 23, 2011 My thoughts exactly Quote Link to comment Share on other sites More sharing options...
RobD Posted January 23, 2011 Share Posted January 23, 2011 When I decatted mine I reset the ecu, but I thought my oxy sensors were on the way out, still stinks of petrol but I kindle like it Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted January 23, 2011 Share Posted January 23, 2011 Are you guys saying go back to stock headers (god I sound like s f*cking yank) Quote Link to comment Share on other sites More sharing options...
Kirk Posted January 23, 2011 Share Posted January 23, 2011 Perhaps a first decat maybe better suited than a manifold although i do have faith that mr whiffins will have been designed with a proper collector. Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted January 23, 2011 Share Posted January 23, 2011 I'm guna see what the dunk results are with the one I have now, will go for Paula anyway in time. I do feel the car lacks low end but really does pull a lot better top end. Quote Link to comment Share on other sites More sharing options...
neo2810 Posted January 23, 2011 Author Share Posted January 23, 2011 If you get stuck mate bring it over mine and I'll have a look for you if you want. Cheers for the offer hodge. I may just do that when I find sone spare time. Quote Link to comment Share on other sites More sharing options...
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