Question about 2005 Fiat Siena

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Fiat sienna rough idle

Engine hunts and wants to cut out at idle if i unplug the idle valve it makes no difference.

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Bad fuel filter, clogged injector possible bad plug-plugs. check air cleaner is new not clogged lacking air at idle can be caused bt this also.

Posted on Dec 28, 2014


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Posted on Jan 02, 2017

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SOURCE: Hello, After driving my car (Fiat Grande Punto

It sounds like you have an air leak to me, or possibly a split small breather pipe where it connects to the inlet manifold.
steve. e

Posted on Sep 14, 2012

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SOURCE: Fiat Punto idles rough and grey smoke

take your cylinder head out and take it to the engineering and ask them to change your valve sterm seals then your problem will be solved

Posted on Oct 23, 2012

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Honda crx with auto transmission idles roughly in drive or reverse. AC on makes it worse.what can cause this?

Idle Speech There are a lot of things that can contribute to an idle issue on your Honda. In fact, in the end it may still be there to some degree because of the nature of a 4 cylinder engine. 4 cylinder engines fire every 180? of crank shaft rotation. Because of this, the crank spends a LOT of time in rotation before the next power stroke. This creates a 'choppy' power delivery that may be most noticeable at idle. So if you have a rough idle with your 4 cylinder Honda, this might be a contributing factor to your rough idle.
The first step I take to solve a rough idle issue is to start with a good tune up. Use NGK or Nippon Denso plugs only in your Honda. Don't change the wires if they're OE (Original Equipment). Honda wires last just about forever so if you still have them on your engine, leave them be unless they show signs of external damage. If you feel you need to change the ignition wires and you want to save a couple of bucks, you might consider NGK wires as they are very good and less expensive than OE. They also come in a snappy blue color! A quality cap and rotor should also be used. I often go with Beck Arnley if I want to save a couple of bucks. Once again, OE is best for these parts. Honda's are VERY picky about the parts you use on their ignition systems. You'd be surprised at the difference between OE parts and aftermarket parts when it comes to Honda ignition systems. Trust me, I've seen plenty of issues here which is why I mention it. I've solved more than one idle issue just with a basic tune up using Honda parts. Lastly, a new air filter is a good idea to add to your list of tune up parts....heck the oil. You'd be amazed at how often I find low oil in an engine. If your Honda is low on oil the engine will have to work harder and possibly run rough as a result. I think it's also important to note here that you need to use the proper viscosity when putting oil in your Honda engine. DO NOT stray from the factory recommendations here. You may think it's a good idea to put thicker oil in your Honda engine, but the truth is that if you do that you can actually starve the top end by doing so. During start up, your engine is almost dry of oil. If you use thicker oil it will take longer for the oil to reach the top end of the engine. Because of this, the cam and valve train do not get oil for some time during start up. When this happens, the parts wear faster and eventually cause things like rough idles.
Don't change the PCV valve unless it's broken or aftermarket. If you see an aftermarket PCV valve, exchange it for an OE valve. Believe it or not, I've seen idle issues caused by aftermarket PCV valves on Honda's. The OE PCV valves last just about forever so you can easily justify the expense. I will admit however that the OE valves sometimes come apart internally and cause idle problems. If that's the case, it creates a large vacuum leak. When this happens, it effects the idle as well as fuel economy. Usually if the PCV valve fails in this manner, you'll experience a 'high' or 'hunting' idle. An easy way to find one of these faulty PCV valves is to pinch off the supply line to the PCV valve with a pair of pliers while the engine is at idle. If the idle smoothes out when you do this, replace the PCV valve with an OE unit.

Sep 28, 2016 | Honda Cars & Trucks

1 Answer

Engine doesn't idle - 1996 dodge Dakota sport

I would give the throttle body a goof clean with carb cleaner making sure the butterfly flap gets a clean due to build up or carbon. If it's not closing properly it will idle rough and possibly cut off. Also might be worth checking the idle control valve.unplug it unbolt it take it off a spray the inside with carb cleaner let it dry and replace. Hope this helps

Sep 03, 2015 | Dodge Cars & Trucks

1 Answer

Fiat Punto idles rough and grey smoke

take your cylinder head out and take it to the engineering and ask them to change your valve sterm seals then your problem will be solved

Oct 23, 2012 | 2001 Fiat Punto

1 Answer

Replaced Fuel filter, Plugs and wires, PCV valve and the Throttle air control valve. Still running rough. Could it be an 02 senor or the catalytic Converter? Car wants to dye out when coming to a stop or...

Hi there, i had a similar problem with my Legacy B4 RSK Blitzen, 2 litre Twin Turbo, Engine EJ208. Car would idle sort of ok when cold, after warming up it would idle erratically (idle hunting) and cut out sometimes. I notices the boost gauge hunting along with the RPM'S .I found it to be 2 faults. 1st fault - If you have an after market air filter and the car hasn't been mapped for the extra airflow past the MAF (Airflow Meter) then it confuses the ecu as its taking in un-metered air. Solution - Re-map car to take extra airflow or as i did, i took out the MAF and cleaned it with a can of Carb&Choke cleaner. It worked but still had rough idle.
2nd fault - Air could be in your cooling system. If there is air in the system then the engine temp sensor is reading hot/cold/hot/cold everytime an air bubble passes by, which will cause running problems. You may hear a gurgling or slushing noise in the car, which is air in the heater matrix. Solution - From cold open the header tank and coolant overflow bottle, un car untill engine warm and hold at 2000-4000 rpm untill you see air bubbles rise in the header tank. Make sure your hot air is turned on in the car and vents open. Do this process for 10-15 mins and when you think all air is out of system then re-fit header tank cap. Have a watering can at hand as you may require to top it up during bleeding. It will overflow but dont worry.

Only real problems Legacy's give are , Air Flow Meters, Knock sensors, and Lambda Sensors (O2 sensor). Hope this helps mate, keep us informed on how you get on.

May 01, 2012 | 2002 Subaru Legacy

1 Answer

Engine stalls when making full stop when AC is on, but when I cut it off it's just fine.

Check when idling and warmed up if the rev drops when the AC is on. It may be too low or is running rough. You may have to adjust the idle screw with little adjustments. If the idle is running rough, inspect the idle air control valve. It may be dirty or faulty.

Aug 21, 2011 | Honda Accord Cars & Trucks

1 Answer

2000 sienna stalls, loses power and engine sounds muffled when I accelerate. idles at only 500 rpm at stop sign and runs rough

After about 100K + miles the idle air control valve (IAC) begins to collect carbon deposits that interfere with the movement of the spring-loaded valve. You will not be able to clean this without removal and dissembly of the IAC body. Use an emory cloth or fine sandpaper to remove the build up around the valve. This should free it up to rotate without binding. This is a temporary fix, of course, and will either require cleaning again or replacement of the valve. Getting to the IAC requires removal of most of the intake upto, but not including, the intake manifold. Total time is approximately 3-4 hours, but worth it. Good luck, and I hope this helps.

Jun 25, 2009 | 2001 Toyota Sienna

1 Answer

Very Rough Idle and sometimes cuts off while idling

sounds like bad Idle Air control valve Not Cheap


Jan 06, 2009 | 1993 Nissan Maxima

1 Answer

1979 fiat spider 2000 multicolored vaccume ports rough idle

auto choke and heated inlet manifold but these are not colour coded from the factory and they serve a function.rough idleing on this type of classic vehicle is down to one thing unleaded fuel causing the valves to burn out,remove cylinder head and decoke and grind valves in ,then use a lead substitute with the petrol

Nov 13, 2008 | Fiat Pininfarina Cars & Trucks

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