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Matt
Matt, Engineer
Category: Car
Satisfied Customers: 20594
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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nissan stanza stanza: car will not idle. i was told to clean

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car will not idle. i was told to clean out intake. i opened throdle sprayed carb cleaner in intake wiped out. car ran fine before service.
Hello

This could be an airleak after the airflow meter, any air dragged in here isn't 'seen' by the ECU and so not compensated for and can lean the engine out and can also allow the engine to rev up when not desired causing rough running.
As its a mechanical fault it tends not to turn on the fault light and you can sometimes hear a 'hissing' noise with the engine running.

Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts.

The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane around each joint in turn. If the engine rev's up you've found your leak.
Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.

It’s also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel being delivered to the engine

Might also be worth cleaning out the idle speed control motor / valve as these get clogged up with carbon and some brake cleaner washed through helps free things off.

Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick fault find if you unplug the meter and run the engine without it.
if the engine condition is the same then chances are the meter or the connection to it is faulty

Air leaks are very temperature dependent as gaps can open or close up as things expand with heat, so the weather and engine temperature can effect them.

This leads them to be quite intermittent in the case of mild leaks

its also worth cleaning the airflow meter by removing it from the car and spraying the exposed sensor wires inside the tube with a brake or switch cleaner - ensure that the cleaner is one of the old fashioned, non Eco type that does not leave a residue

On no account touch the sensor wires with anything physical as they are extremely fragile
Customer: replied 4 years ago.

stop i am not a micanic will you walk me threw this. car ran fine befor i put carb cleaner in open intake. it will not idle it run with my foot on exelerator at 2000rpms I took intake hose off. i do not underst and your exlpinations you will have to talk in lamans terms. d

DO YOU HAVE THE TIME I NEED TO GET TO WORK

 

 

Hello

OK not a problem

the hose you removed to spray cleaner into the intake - 1st check that its securely tightened at both ends as its needs to be air tight

I'm assuming that where you sprayed the cleaner was into the engine intake manifold so the 1st metal part of the engine where the hose is attached
check that the throttle cable which runs to this point isn't snagging and that the throttle opens cleanly with no sticking
Customer: replied 4 years ago.
it opens and closes. I took intake hose off again and checked its off now. it ran bad last night.
Hello


Ok if you follow the intake hose back from the engine there should be a device with an electrical plug on it thats just after the air filter box

it'll look something like this:

graphic

this is the airflow meter check that its plug is properly connected and that its wiring isn't damaged
Customer: replied 4 years ago.

you are helping half the problem is gone engine running good.not like last night. but will not idle. I will go down and check the part you showed me. Pease bear with me its almost fixed.

 

Ok

if you're back to it just not idling then the thing I showed you needs to have an airtight seal after it

as air dragged in post meter will lean the engine out - reduce its fuelling

so do a careful check of all the little rubber hoses etc on the inlet manifold and quite often you can hear a 'hissing ' noise for an airleak with the engine running

if all of this is OK then its possible that the idle speed control valve which will be on or around the throttle is clogged up

I think it looks like this on yours:

Customer: replied 4 years ago.

I did install a new K&N air filter had my hands all over the small hoses down below. I checked them out just now.How do i troble shoot if it wont stay ruuning unless i have my foot on the gas.

Hello

well we're now back to my original suggestion of spraying lighter gas around each joint - see above

also try removing the idle speed valve and use some brake cleaner to blast through it and ensure that its not sticking

failing all this you can raise the idle speed with a little adjustment screw normally

it'll be on the throttle body somewhere and either open the throttle a little or increase the amount of air running to the idle valve
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Customer: replied 4 years ago.

how can i get your help in future i was on line with just answer 8.5 hr. you were great to walk me threw it. you saved the car k&n filter makes me touch te exelorator very slowly. wow

 

Hello

glad to have helped
just come back and ask for me and I'll try to help