another idle problem 91 240sx

[Seolwen]

ok ive searched and havnt found the right answer yet so here goes.i have a 91 automatic 240sx that runs fine when cold, but once it warms up i can feel it hitching at speed not constant but enough to notice. and when i come to a stop the idle becomes real rough, bounces between 700-400 is worse when it is in drive, has stalled on me 4 times in the past week. also bogs down when taking off (again only after it has warmed up). but the car still hits triple digits easily.

-have checked the maf-cleaned the iacv-new tps-new plugs, wires and distributor.

any ideas?
Modified by Seolwen at 8:20 PM 1/27/2007

[Dano]

Did you replace the whole distributor or the cap and rotor or what?

Sounds like either timing is off or the iac is bad...

-Dan

[Acecool]

fpr hosesinjectorsalternator

could be many things..

[Dano]

fpr hosesinjectorsalternator

could be many things..

Could be, but since he claims it runs good at anything except idle, but acts normal on cold idle seems to rule out those IMO.

-Dan

[Seolwen]

Did you replace the whole distributor or the cap and rotor or what?

Sounds like either timing is off or the iac is bad...

-Dan

just the cap and rotor.

[boriquaS13]

question have you noticed any black smoke from tail when taking off and orduring the bog? Also check for vacuum leaks, if your not sure how take some carb cleaner and spray a light mist around your vacuum hoses and intake manifold gasket etc. Check that you do not any cracks in your intakehose between your maf and throttle body including hoses attached to your intake hose. Another possibility is if your 240 is infact epuipped with an egrvalve (my 89 240 is) disconnect the hose going to the egr valve while theengine is idleing see if it smooths out. If it does you need to find out whyyour are getting vacuum at the valve at idle. Possible faulty egr valve tansducer? Anyway goodluck and hope this helps

[boriquaS13]

Just forgot to mention that when spraying the carb cleaner it will cause theidle to smooth out. Basically what your looking for is a change if there is look around that area for the vacuum leak. Again good luck!!