idling bumps

[RicKii``]

when idling, my cars engine jumps and stuff...hard to explain but it just not smooth idling. is it fuel? annoys the crap outta me when im at the lights and can feel the bumps but the car isnt moving!!
does anyone have this problem when they are idling?

 

[doommachine]

Yep. My car needs to be tuned really really badly though

My 300zx (completely stock n/a) does the same thing.

 

[EVO-00X]

Is it the idle that jumps? or the engine physically moving? Your problems may be associated with anything from the idle stepper controller to dodgey engine mounts which sounds more like the cause to me. Pop open the bonnet with the engine running and give the throttle body a few good revs. Whilst doing this see if the engine looks like it moves excessively. If so, turn the car off, jack it up or put it on ramps and grab a torch and have a good look at all of the engine mounts, including both on the crossmember (one is behind the radiator and the other is behind the engine near your power steering rack), also check the one on the hanger for the gearbox and the front one next to your timing cover. Sometimes they might look fine but shake the engine about and you will see if they are split or broken.

 

[doommachine]

I think he means it "pops" when idling, like it will idle smoothly and then it will pop and the revs drop a little bit.

 

[RicKii``]

hmm, well the engine rpm is still at the same position and ive got a AVCR and thats not showing a big increase or decrease in rpm either but the engine seems like it is bouncing i have noticed the exhaust is getting more loud and i tighten all the bolts up and couple of weeks-month later the bolts come loose. the exhaust guy told me to check engine mounts as when the engine is moving more excessively than it should, will move and slowly loosen the exhaust. possible?

 

[rvrftw]

I've experienced the same problem ricki... the engine sounds like it is missing every now and then, but no change in revs.... really annoying

 

[BMGTZ]

check ignition components, clean injectors as well.

dodgy engine mount s will "allow" movement that can be felt but not be the cause of the movement.

 

[3zercrowd]

Leaking BOV :wink:

Reverse it to test if any change.

Which one do you have? Stock?

Get an EVO8 MR BOV :wink:

 

[GSR94T]

hey 3zercrowd - could he just temporarily block off the blowoff altogether instead for a test.. just curious what does reversing it do? - or does this do the same effect as blocking it off?


anyway back to the problem - could be plugs, leads, **** fuel as mentioned...

put some good fresh fuel and injector cleaner, plugs and leads are dirt cheap anyway...
though i dont like how those bolts are coming loose every week - bit sus .. :shock:

 

[3zercrowd]

hey 3zercrowd - could he just temporarily block off the blowoff altogether instead for a test.. just curious what does reversing it do? - or does this do the same effect as blocking it off?

YES Reversing it WILL block it off, hence why i said it.

I went from a badly leaking Turbosmart type 2 to an Evo8 MR BOV and never looked back :wink:

 

[GSR94T]

YES Reversing it WILL block it off, hence why i said it.

I went from a badly leaking Turbosmart type 2 to an Evo8 MR BOV and never looked back :wink:

learn something new everyday 8)

 

[doommachine]

I read about something similar the other day on a honda forum ducks: .. through google I swear!) basically the guy went through every possible component, testing and swapping with other cars.. eventually he had his injectors cleaned, and it helped it a bit (they were so filthy they looked as if they were coated in grease) and eventually he just got new injectors... solved the problem 100%.