low RPM problem

[jhvaron]

I have notice that when I go low RPM/ low speed or I have my engine in idle for some time, my engine like choke itself and starts like when a spark plug is bad, it doesn´t even itself, you can see the engine bouncing. My nissan dealer put the computer on it, and tell me that everything is "all right" but it still doesn´t feels right.

 

I´m thinking that the injector are putting to much fuel and overfull the engine in low RPM or a sparkplug is bad. But the thing is that it is not allways that does this uneven engine movements.

 

any of you guys know what it can be, and how can I fix it?

 

thanks for the help.

Edited March 24, 2014 by jhvaron

[ferrariowner123]

Check all of the air/fuel sensors. Make sure you're air filter is clean. Make sure Maf is clean. Run a obd2 scan, make sure O2's are working. They car can only go off what it can see from the sensors, chances are one of those are bad. Not the injectors.

 

-Kyle

[jhvaron]

Check all of the air/fuel sensors. Make sure you're air filter is clean. Make sure Maf is clean. Run a obd2 scan, make sure O2's are working. They car can only go off what it can see from the sensors, chances are one of those are bad. Not the injectors.

 

-Kyle

man thanks for the input.

 

I'm changing the air filter and found a hose broken. trying to fix it I broke a intake hose and now I have to fix that.

[ferrariowner123]

that intake hose was probably it.

 

It will let more air in past the MAF thereby screwing up the air fuel mixture...

 

-Kyle

[jhvaron]

well. the problem has not disappear completely. It when went down 50%. so we are in the right track.

[ferrariowner123]

Check for any other vacuum leaks, when were the spark plugs changed last? how many miles are on your rig? on the VG33e's, the service intervals for spark plugs are every 30K. have you messed with the mechanical timing at recently? (ex. timing belt, adjusted the dizzy, TPS sensor) inspect your spark plug wires, those can where out after time...

 

Thats all i got off the top of my head..

 

Let us know what you find.

 

-Kyle

[jhvaron]

Check for any other vacuum leaks, when were the spark plugs changed last? how many miles are on your rig? on the VG33e's, the service intervals for spark plugs are every 30K. have you messed with the mechanical timing at recently? (ex. timing belt, adjusted the dizzy, TPS sensor) inspect your spark plug wires, those can where out after time...

 

Thats all i got off the top of my head..

 

Let us know what you find.

 

-Kyle

 

I have to look for the other vacuum leak. when I restart the engine after the last fix, I can hear the leak but haven´t been able to pinpoint it.

 

this rig has 224,000 km (139.000 mile aprox) and it was sincronise by the nissan dealer 2 month ago.with change all the sparkplugs, and wires.

 

were can it be the other vacumm leak?

 

thanks allot for your help.

 

Juan

[fixinto]

check the small vacuum hose that plugs into the back of your air box. there should be another hose that plugs in under your throttle body. Another good thing to replace is your PCV valve. easy to replace and if it goes bad in the wrong way, it can effectively cause a vacuum leak minor enough that your engine wont die, but will run rough and stumble at idle. EGR shouldnt be used at idle but if it goes bad can cause something similar as well. hope this helped u out in some small way. let us know what u find.

 

 

 

 

Pat