View Full Version : Very very strange cutting problem on my sr20 that I cant sort - please help!!
I have an ongoing problem with the red top sr20 in my 180sx loosing all power at 5500rpm....
It all started a month ago when I upgraded the power to 350bhp using the following parts:
Nismo 740's
Garrett 2871R
Ngk bcr8es's
Z32 AFM
Nistune ECU
Every thing was fine when being mapped and it drove very well on the way home......
Up until the point when I accelerated hard out of a roundabout and hit what can only be described as a fuel cut at 5500 rpm.....
The car has now had two other good ecu's, another good AFM, the speed sensor disconected from the gearbox so it doesnt know the road speed...
It happens with the boost controller on and off.....and in any gear!!
You can however avoid the cut by using progressive throttle and will drive through 5500 no problem!!
Just to sum up.....the problem only happens under load so you can drive through it on a lighter throttle but when it cuts its very smooth with no stuttering..its as if someone flicks a switch and then when you fully lift off the throttle and re-apply its fine!!!!
It must be a component which couldnt handle the hike in power and has broken on the rolling road....what? Knock sensor?
Any ideas would be much appreciated :thumbs:
Exact same symptoms as mine. It was the coilpacks, in the end.
redsx94!
11-07-2010, 14:17
Maybe somethings happened to the map. Is it a violent loss in power or does it just die like switching the ignition off while accelerating.
martinbattye
11-07-2010, 17:32
I have an ongoing problem with the red top sr20 in my 180sx loosing all power at 5500rpm....
It all started a month ago when I upgraded the power to 350bhp using the following parts:
Nismo 740's
Garrett 2871R
Ngk bcr8es's
Z32 AFM
Nistune ECU
Every thing was fine when being mapped and it drove very well on the way home......
Up until the point when I accelerated hard out of a roundabout and hit what can only be described as a fuel cut at 5500 rpm.....
The car has now had two other good ecu's, another good AFM, the speed sensor disconected from the gearbox so it doesnt know the road speed...
It happens with the boost controller on and off.....and in any gear!!
You can however avoid the cut by using progressive throttle and will drive through 5500 no problem!!
Just to sum up.....the problem only happens under load so you can drive through it on a lighter throttle but when it cuts its very smooth with no stuttering..its as if someone flicks a switch and then when you fully lift off the throttle and re-apply its fine!!!!
It must be a component which couldnt handle the hike in power and has broken on the rolling road....what? Knock sensor?
Any ideas would be much appreciated :thumbs:
if its not coilpacks it could very well be the adjustment of the TTPmax and TPmax limits in the nistune..
if it was dyno tuned only.. (not road tested afterwards) there is a very high chance that the loading on the motor is different to that of the dyno.
Maybe somethings happened to the map. Is it a violent loss in power or does it just die like switching the ignition off while accelerating.
Its like someone just switching a switch...only seems to happen when I'm nailing it!!!!
Thr problem is also intermitant which is annoying but always happens when you take the car out...
Definately not the coilpacks...definately not a colapsing pipe...the map is spot on...Nistune in Aus have looked at the data logs of tps, fueling etc and theyre sratchin heads...very strange
is nistune switching to the knock map at that point? as martin said, dyno run would not simulate road conditions and it could be seeing knock and switching to a safe map.
redsx94!
13-07-2010, 19:16
Mines did this when the intake was collapsing when it was sooking. Is your intake hose mostly rubber if so this is your problem.
redsx94!
13-07-2010, 19:46
It seemed on mine that while accelerating when it got to higher revs it felt like someone switching the ignition off.
It seemed on mine that while accelerating when it got to higher revs it felt like someone switching the ignition off.
That is exactly what its like!!!
How do you test this??
I took the air filter of to try and stop the suction building up but it still did it!!
redsx94!
14-07-2010, 09:37
You would have to make a hard pipe. What exactly are you using as an intake from the turbo to the afm?
You would have to make a hard pipe. What exactly are you using as an intake from the turbo to the afm?
I'm using the standard 180sx redtop rubber intake tube with an apex z32 afm adaptor.....
The car is running 1.3 bar of boost on a 2871r
redsx94!
14-07-2010, 20:24
Does it still have the metal springy thing inside the rubber hose to give it strength.
nistune have safety settings for knock and load and if the engine over heats it will switch to the safe map if anyone of these are activated this is probably what is happening ring the man who mapped it and tell him the situation it will probably be a two minute fix most likely the knock sensor tho
redsx94!
14-07-2010, 22:20
I doubt it would kill the power like switching the ignition off while on full throttle if it was hitting a safety feature of a map.
that depends on what way the mapper set up the safety map mine is set to over fuel like crazy
Did you ever sort this out?
Yeah its all sorted now thanks....turned out to be as REDSX94 said!!
It was the standard intake trunking colapsing!! The spring inside had moved inside the pipe
so it was returned to its correct position and now its running perfectly :thumbs:
Gonna be giving it a full rinse at Mallory park on oct 14th...
redsx94!
30-08-2010, 18:18
Your welcome lol
You should invest in making a hardpipe intake though.
Your welcome lol
You should invest in making a hardpipe intake though.
I will when I can get round to doing it...:thumbs:
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