HELP! Problems with new 347
08-15-2010, 01:35 PM
#1
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HELP! Problems with new 347 ok, fired up the new motor last night, everything sounds good, no leaks, rattles, ect. (knock on wood).
its a 347, prc heads, big cam, ect.
the problems im having:
have to open the throttle some when i start the car(blade already has larger hole and has screw cranked out).
car will idle fine at like 1100(big cam), but then out of nowhere it goes to like to 300 rpm(seems like when it goes out out of open loop, but car is locked in open loop??).
and when it does idle way down, i can push the gas and it wont rev. wtf? it will take 4-5 seconds before rpm will rise.
basically the only sensors it could be pointing to, would be the MAP, TPS, IAC, IAT, KNOCK, CAM, CRANK. now obviously we can rule out a few.
not cam/crank- car will run good when it does run, throttle response is awsome.
not maf- tune doesnt use it
not iac- i dont see why this would be doing it.
not o2s- tuned out
not tps- unplugged it and went SUPER rich. so must be working
not knock- not
not iat- shouldnt matter
only one i can think of is the MAP. i had to extend it for the ls2 intake, that might be messing things up???
im not sure what else to look for.
its a 347, prc heads, big cam, ect.
the problems im having:
have to open the throttle some when i start the car(blade already has larger hole and has screw cranked out).
car will idle fine at like 1100(big cam), but then out of nowhere it goes to like to 300 rpm(seems like when it goes out out of open loop, but car is locked in open loop??).
and when it does idle way down, i can push the gas and it wont rev. wtf? it will take 4-5 seconds before rpm will rise.
basically the only sensors it could be pointing to, would be the MAP, TPS, IAC, IAT, KNOCK, CAM, CRANK. now obviously we can rule out a few.
not cam/crank- car will run good when it does run, throttle response is awsome.
not maf- tune doesnt use it
not iac- i dont see why this would be doing it.
not o2s- tuned out
not tps- unplugged it and went SUPER rich. so must be working
not knock- not
not iat- shouldnt matter
only one i can think of is the MAP. i had to extend it for the ls2 intake, that might be messing things up???
im not sure what else to look for.
08-18-2010, 12:13 AM
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Yes it does sound like a tuning issue to me also , have never tuned a really big cam , but a friend of mine almost drove himself nuts trying to untill he decided to seek help , help is good , how big is the cam Eric
