i have an 04 enthusiast with about 16k

i just started to experience a rough idle at about 700 rpm and the car used to be around 750 rpm solid before. any ideas what could cause this?

thanks in advance

rw

 

Do you have a plenum spacer? When the bolts start to become loose you get a rough idle.

 

maf cleaning might help

 

i have the crawford upper plenum but the idle has always been fine until now.

i

 

I'm kind of having the same problem. What are some solutions? So far:

Check bolt torque #'s
Clean MAF

What else guys?

 

here is the link for cleaning the maf https://my350z.com/forum/engine-drivetrain-and-forced-induction-diy/55677-how-to-cleaning-the-maf.html

going to try both suggestions this weekend...will post results

 

Remove intake tube and take a look at the throttle body... might need cleaning as well.

 

there are 4 main possibilities. even with Consult its hard to narrow it down.
1.maf
2.throttle body
3. injectors
4.coils

mine is screwing up on 3 cylinders at 60k from clogged up injectors. best thing for you to do is take it to nissan so they can do a power balance test to see which cylinders are not putting out and look at ecm input values. cheap gas will mess your injectors up and using injector cleaner with your fuel is never a bad idea.

 

I wouldn't rule out a vacuum leak, but I would definitely start off with a maf cleaning as Al S14 suggested.

 

Ok... cleaned the MAF as well as re-tightened the upper plenum (have Mrev2 and spacer). Rough Idle is still there. Gonna clean out the throttle body later see what happens

 

get some carb cleaner and carefully spray it around plenum gasket with it idleing.its best way to check for leaks but careful not to spray down low it may catch fire from the exhaust...not likely but possible. or better yet hook up a vacuum gauge.

keep in mind whenever you clean or replace a maf you need to clear out and do idle air volume relearn and reset alphas otherwise computer will run off old values. can only be done with Consult. this is just an FYI i don't think its will help you in this particular case. i am about to make a bet that cleaning TB wont help. its never that easy lol. should have gotten a honda if you wanted a car that never breaks


what you mentioned above is exactly same thing i did. only i had access to brand new parts which i just tried then returned back to parts dpt i am pouring injector cleaner in lke crazy hoping it will take care of it...i THINK it got better but its probably all in my head. if it doesnt get any better i will try an injector cleaning ...

 

ok...cleaned maf and made sure all plenum bolts were torque'd to spec and still experiencing rough idle.

i cleaned my tb not too long ago when installing my mrev2.

going to check for leaks next