[iansr33]

Just went out for a drive to test my office coilovers and after it warmed up i went to floor it. Put foot ll the way down and it was either misfire or holding back at the above revs, it was ok at three quarters throttle but no full. Someone please help as im off to the ring next month.

 

[ChrisC]

Hmmm, i would check coil packs plugs that sort of thing

 

[iansr33]

got a new wasted spark setup thats 2k miles old, will try new plugs

 

[Bruce-m]

could be air flow meter.

Although i had a similar prob from 4-6k rpm and it was my knock sensors.

 

[iansr33]

will hook up my laptop with datascan and see what fault codes if any it gives me

 

[iansr33]

connected data scan and it came up with no faults

 

[MARKPRIOR]

i would take out plugs if your running higher than std boost pot nearest the radiator normally melts the end off

 

[topo]

ive had this all last week mate tryed plugs new filter removing dumpvalve etc etc turned out to be dirty afm ! must be from all the rain ! cleaned it with carb cleaner and a little paint brush and she flys now very crisp and revs to red line no probs it did hold back at 6k

 

[iansr33]

will give it a clean when it stops raining

 

[tigger]

in no particular order - plugs, coilpacks, AFM, lambda sensor possibly. or could poss be knock sensors a la bruce.

 

[iansr33]

dont plugs, have wasted spark set up, nearly new lambda sensor ( 200 mile old ) so will try the old afm circuit board trick this weekend. i did connect up my laptop and datascan and it gace no fault codes.

 

[DynoTuner UK Ltd]

First thing to check would be fueling and ignition and then you can try and get a idea of where to look. Its sounds like a the knock sensors are picking up some noise and reducing the power to protect itself.

Richard

 

[iansr33]

if its over fueling would this make sounds that the knock sensor's could hear? also is there a test i could do on them and where are they on the engine. did the old afm dry joint trick today and put new solder on it but still the same.

 

[DynoTuner UK Ltd]

If the knock sensors pick up excess engine noise or det they will retard the ignition and chuck a load of fuel in which gives a flatspot. I`v seen it a few times. Somtimes its faulty knock sensors or somtimes its other things! Not easy to say without seeing it but the knock sensors can be faulty and not give out a fault code.

 

[iansr33]

do they cost a lot to get new ones? as you may know im off to the ring next week and i want a fast car to go in

 

[iansr33]

it is using too much petrol

 

[DynoTuner UK Ltd]

Knock sensors are quite expensive from nissan. I think they are somthing like £130 + vat !!

If you want to bring it down and run it on the dyno we can check it over and try and fix it before you go. Better to be safe than sorry as the last thing you want to do is break it over there!

Richard

 

[iansr33]

have you a rough cost please richard, pm me details please, BIG BIG thanks