bucking and cut out?crazy crank and cam sensor readings?
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bucking and cut out?crazy crank and cam sensor readings?
i am trying to set this up still.i got on the gt35r kit for the first time today and it ran ok till about 13 psi at 5000 rpm.then it bucked and felt like it went into fuel cut.it stayed un responsive and went straight down and stalled.the tach jumped all around and then went straight to 0 rpm.it restarted and idled ok but bucks and jumps violently when pushed past 3k rpm or under more than 25 tps load. i loged it a few times and then looked at it and my crank and cam graphs looked crazy. does this look normal to you guys?have not logged that before so do not know what it looks like.this acts very funny like a bad fuel cut or unresponsive at any rpm and throttle position. i put a new crank sensor on it when we put it together three weeks ago.any ideas guys ?any help would be great.thanks i attached three
of the logs i did.
of the logs i did.
#2
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If I were getting symtoms like that, the first thing I would check is boost leaks and proper MAP/Temp sensor setup. Also check under rev limiters to see where your boost cut is set. I know that is obvious, but sometimes the obvious is overlooked. Worse case you have an electrical issue.
If you have adjustable cam gears that can make things interesting too. If it is a legit cam sensor issue then I would think your timing would be off at idle as well.
If you have adjustable cam gears that can make things interesting too. If it is a legit cam sensor issue then I would think your timing would be off at idle as well.
Last edited by fre; May 30, 2008 at 08:31 AM.
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i think the issue is between the crank tooth plate and the crank sensor.not to sure whats wrong with it but after watching it more on logger and pro just funny readings and seems wrong.dont know im going to try to limp her back 612 miles home today and see.keep fingers crossed.
fre as for boost leaks i cannot even come on boost now anything close to 3k and it acts up.
as for map set up i did not change what was set up from before.i have found other mistakes in their maps and corrected them.rev limiters are 7k across the board for safety till it gets looked over better.do have adj cam gears but set at 0 deg on both.timing marks were all lined up when put together.im out on vacation away from home and have very little access to tools.but i remover the cover and spun her over and all still look ok by timing marks.
awd yes timing from mechanical side looks to still be on.the knock control under knock sensor set up is checked and on.
thanks for the help guys.
fre as for boost leaks i cannot even come on boost now anything close to 3k and it acts up.
as for map set up i did not change what was set up from before.i have found other mistakes in their maps and corrected them.rev limiters are 7k across the board for safety till it gets looked over better.do have adj cam gears but set at 0 deg on both.timing marks were all lined up when put together.im out on vacation away from home and have very little access to tools.but i remover the cover and spun her over and all still look ok by timing marks.
awd yes timing from mechanical side looks to still be on.the knock control under knock sensor set up is checked and on.
thanks for the help guys.
#5
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What I meant by MAP sensor is the sensor itself, not the timing or fuel maps. If the sensor was calibrated incorrectly that could throw everything off (i.e. set up as a 5 bar map sensor when you have a 3.5 bar). If it is an issue with the crank position sensor then I am not sure what to tell you. The plate on the crank has a notch in it and the sensor only bolts on one way, so unless the plate was bent or you had a bad electrical connection? I guess you would want to make sure the plate on the crank is on the correct direction. You should be able to tell from rubber off the balancer shaft belt being on the back side from slight rubbing. Also the crankshaft sprocket usually will leave marks on the front side of it. If I remember correctly, the plate has a slight dishing on one side too, I think it is the front side, but am not positive. That would be so far off timing though that I wouldn't think it would run or it would destroy your valves, so that probably isn't the case.
Last edited by fre; Jun 1, 2008 at 02:26 PM.
#6
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i dont have any personal logged cam & crank data...so i cant comment on that, however it looks like the car drives ok for the most part within the "buckked" zip data until it runs like crap
what map sensor are you using? what units?
you cant see what afr's your getting either, so it make sit difficult to see if the basics are even correct.
what map sensor are you using? what units?
you cant see what afr's your getting either, so it make sit difficult to see if the basics are even correct.
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