Guest jerry302 Posted March 6, 2005 Share Posted March 6, 2005 i have an 85 300zx n/a and i cant get the engine to run correctly, the only parts on the car that arent stock are the electric fan, i took the resonator off the intake, and i have a 89 240sx throttle body on it because its bigger. now to the problems, it starts and runs fine but not all the time, sometimes it will hesitate and make no torque and sputter to the piont where the car cant accelerate it does this from idle (800 rpm) to about 2400-2500 rpm then i put my pedal to the floor and its starts to slowly accelerate intill 2400 rpm then it takes off. the problem was intermittent and recently its been toing it all the time. i ran diagnostics on the ecu and it gave me ignition signal, air flow meter, idle switch, and feul temp sensor. today i was sitting in my riveway listening to the motor as it went up the rpm range, and the car revs fine but if i hold the pedal at a constant rpm it stays there for a second then the rpms go down about 300 less than its supposed to be and the engine runs roughly and sputters. i tested the air flow meter and it looks ok(i tested it the way it says to in the factory service manual) i believe the throttle position sensor it ok but i have not checked it and i havent checked igniton or my o2 sensor because i dont know how to, and i would like to know how i can check the fuel pressure regulator. Quote Link to comment Share on other sites More sharing options...
RedBeauty84ZX Posted March 6, 2005 Share Posted March 6, 2005 Does it do this even after the engine has been running for a while and is warmed up? It sounds too me like the CHTS or the Auxillary Air Control Valve. Quote Link to comment Share on other sites More sharing options...
Guest jerry302 Posted March 7, 2005 Share Posted March 7, 2005 it does it after the engine warms up i dont think its ever done it with the engine cold, and i took apart the idle air control valve assembly and cleaned it. .....what does CHTS stand for. Quote Link to comment Share on other sites More sharing options...
cheftrd Posted March 8, 2005 Share Posted March 8, 2005 Dribbling fuel injector(s). Quote Link to comment Share on other sites More sharing options...
Guest jerry302 Posted March 16, 2005 Share Posted March 16, 2005 how can i check my injectors, and what should i buy for new ones if i need them, what do you mean by dribbling ....there not closing all the way? Quote Link to comment Share on other sites More sharing options...
cheftrd Posted March 19, 2005 Share Posted March 19, 2005 They're old and may have nozzles that are partially clogged, not closing all the way, or the end of the pintle long gone. They can be serviced, but most of the Z32 TT injectors I've ever delt with are almost impossible to get out of the buckets without ruining them due to years of being baked. They may have a bad spray pattern or not closing all the way which makes the engine run like crap in the lower rpm's but won't be noticable in the upper range. Quote Link to comment Share on other sites More sharing options...
cheezmonta Posted March 27, 2005 Share Posted March 27, 2005 This sounds like a bad 02 sensor to me. My 89' Z31 did the same thing. It seemed to run good till it warmed up then it started to sputter and lack power. I ran the ECU and everything came back fine but was not. I ended up changing the 02 and the prob went away. It couldn't hurt to change the 02 anyway. Look at it as preventative maintenance. Quote Link to comment Share on other sites More sharing options...
boostedz31 Posted April 15, 2005 Share Posted April 15, 2005 chts.. cylinder head temp sensor. I think this is your problem and it only cost 23 dollars at oriellys auto parts. the chts is telling the engine it is cold when it is cold.. and it is tellen the engine it is cold when it is hot as well... this will make it run really rich.. causing the problems you describe. the o2 probably needs to be replaced as well, as they get old and a new one generally provides better performance/gas mileage. the chts is on the front of the driver side head, you minds while put on a new timing belt, tensioner, and water pump while your at it. i put a chts on my shiro and it cured my problems.. runs great while cold, but crap when warm.. no shes right on. except for my o2 is dead along with the full throttle contact being busted off the tps... good luck. Quote Link to comment Share on other sites More sharing options...
RedBeauty84ZX Posted April 17, 2005 Share Posted April 17, 2005 chts.. cylinder head temp sensor. I think this is your problem and it only cost 23 dollars at oriellys auto parts. the chts is telling the engine it is cold when it is cold.. and it is tellen the engine it is cold when it is hot as well... this will make it run really rich.. causing the problems you describe. the o2 probably needs to be replaced as well, as they get old and a new one generally provides better performance/gas mileage. the chts is on the front of the driver side head, you minds while put on a new timing belt, tensioner, and water pump while your at it. i put a chts on my shiro and it cured my problems.. runs great while cold, but crap when warm.. no shes right on. except for my o2 is dead along with the full throttle contact being busted off the tps... good luck. BoostedZ31, where at in Arkansas are you located? Quote Link to comment Share on other sites More sharing options...
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