My S13 has flat spot and backfires
Posted: Fri Jan 20, 2012 11:31 am
Hi guys, like i said in another thread my car really struggles when it is cold, even to pull away at 1500rpm it stutters and feels like its missing, once it has warmed up to normal temperature it drives very nicely but occasionally there will be a bit of a flat spot just before boost and when boost kicks in she will fly, also if im coming off the freeway and i just take my foot off the gas and stay in the current gear, as the engine revs slowly drop i sometimes will get a few fairly loud backfires at around 2800rpm but this does not always happen.
I have fully serviced my car yesterday, diff oil, gearbox oil, engine oil, fuel filter, oil filter, and spark plugs (bcpr6es-11 gapped to 0.8mm) It still does the same thing, the car drives nicely and i hope this is not a huge problem as its just a bit irritating.
Could it be bad coils? ive checked my spark plugs numerous times and they all nice and dry and look fine and all my coils and plugs are connected correctly, i also noticed that it looks like my cam angle sensor has been rotated a bit as there is a sticker on the cam cover and a sticker on the angle sensor but they do not align (not sure if that would make any difference)
Oh also i must add that my idle isnt great, if i leave it for long she will idle at about 750rpm, but if i rev it to about 2000rpm then itl idle at about 1500rpm for a while before it slowly drops to 750rpm.
Could it also be a bad air flow meter? I remember my friend having similar problems with his nissan almera because his airflow meter was messed up. Plus i also have a 76mm complete free flow exhaust without any silencers, just a f1-x 100mm tail box, perhaps its too free for the stock turbo?
My plans were to take it to Dynotec and get a uniq chip fitted and let him just tune it for feuling but i'd feel better knowing everything is 100% before i let anyone Dyno it.
I always say - Maintanance over Modification
So what do you guys think?
I have fully serviced my car yesterday, diff oil, gearbox oil, engine oil, fuel filter, oil filter, and spark plugs (bcpr6es-11 gapped to 0.8mm) It still does the same thing, the car drives nicely and i hope this is not a huge problem as its just a bit irritating.
Could it be bad coils? ive checked my spark plugs numerous times and they all nice and dry and look fine and all my coils and plugs are connected correctly, i also noticed that it looks like my cam angle sensor has been rotated a bit as there is a sticker on the cam cover and a sticker on the angle sensor but they do not align (not sure if that would make any difference)
Oh also i must add that my idle isnt great, if i leave it for long she will idle at about 750rpm, but if i rev it to about 2000rpm then itl idle at about 1500rpm for a while before it slowly drops to 750rpm.
Could it also be a bad air flow meter? I remember my friend having similar problems with his nissan almera because his airflow meter was messed up. Plus i also have a 76mm complete free flow exhaust without any silencers, just a f1-x 100mm tail box, perhaps its too free for the stock turbo?
My plans were to take it to Dynotec and get a uniq chip fitted and let him just tune it for feuling but i'd feel better knowing everything is 100% before i let anyone Dyno it.
I always say - Maintanance over Modification
So what do you guys think?