hi my car wich is a 1992 300zx uk tt manual is misfireing when it gose over 1500revs its ok below that and its ideling ok is well so come on guys what can it be ptu? afm? would be great full for any help thanks :bow:

where in england you live bud??

Ibran,

 

See........ http://www.300zx.co.uk/forums/showthread.php?t=51346

 

Sounds fimilar!

 

Rich

west yorkshire near leeds mate

come on guys need urgent help please please i tryed the link above but cant understand can anyone point to the right thing or do i have to try everything?

If you have a fault with the airflow meter it won't let you rev over 2000rpm. Is that what's happening?

 

Otherwise i'd check your spark plugs and all the coil pack connectors that sit above them.

 

There's loads of things can cause this so have to try a few things and give us some more info.

 

Where are you near Leeds? I'm from Leeds and work there so might be able to take a look if you get stuck.

 

Chris.

a vacum leak was the cause of my missfire :cool:

do an ecu check

chris i m near bradford and i have new plugs in the car but still the same i have checked the coil leads they look ok and yes i dont think it gose over 2000revs what happand was that i had an accedent and had to change the afm and the box so it could be that becoz i got a 2nd hand one if u hav any ideas how to make sure its working let me know thanks

how do you check for vacum leak?

can be tps (throttle position sensor) located on end of throttle bodies, tells ecuhow far open the throttle is, a dodgy signal ie corroded connector will result in wrong timing advance at certain revs in your case 1500 to wherver it may be, i had same prob between 4500 to 5500 revs, was told it would be cas (crank ngle sensor) worked out it was tps myself and changed connector. if contacts look green in the connector its quite likely

also is the car ok when cold but prob when warm, can be coolant sensor for ecu, fron of engine, orroded connector, will cause the ecu to think car is cold all the time, ok until its warm and choke stays on causing car to run rich, coke up plugs and detonate which will cause limp home mode ie not rev above 2k revs. check the plugs to see if they are coked up, if so car wll be running rich due to sensor fault.