Faulty injector???

[apostolis]

Hi Eric,Hi everyone greetings from Greece!!!.First i would like to gongratulate you for your videos, they are very informative and detailed and the quality of your work is very high. My name is Apostolis and i hane a problem with my car. Its a Renault Clio mk3 1.4 petrol 2006 model. It started to run poorly and the check engine and fuel injection computer lights came on and when i stepped on the gas the fuel injection computer light was flashing but when i stepped off the gas the fuel injection light turned off. After some time(10 min) both lights turn off and the car runs perfectly. My OBD scanner showed codes P0203 & P0303. Then i cleared the codes and swiched spark plugs and coil plugs from #2 and #3 cylinder. After a while the engine missfired the same codes appeared and then(after 5-10min) it run perfectly again. The fact that even though i swiched coil plug and spark plugs the fault remains on the #3 cylinder makes me think that i might have a faulty injector. When the problem started i did put an injector cleaner product in my tank and after all the gas was consumed nothing happened. Any ideas?

Keep up the good work and stay dirty!

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[Its me]

You are on the right track… change injectors just like you did with the spark plug… the P0203 shows an issue with the wiring signal at #3 injector. Could be the wiring or the injector..

[apostolis]

Thank you. I have to find some time for that. In order to access the injector rail and the injectors i have to remove the intake manifold (the rail is underneath the manifold). There is almost no room to work in the engine bay. If I swap injectors #3 &#2 (as i did with coil plugs and spark plugs for the same cylinders) and the code is still P0203 the wiring will be faulty, if the code is P0202 the injector will be faulty.

[EricTheCarGuy]

You may want to table the injector theory for now. There are other things that can also cause a cylinder misfire of that type. If there’s a mechanical issue with the engine such as a loss of compression. It could also be caused by a vacuum leak or ignition problem. I know you said you swapped the spark plugs, but perhaps there’s an issue with the ignition system that supplies voltage to the plug.

I would start with a power balance test to verify the offending cylinder(s). Sometimes the computer isn’t very good at picking up exactly where a misfiring cylinder is. Therefore, I think it’s a good idea to verify what the computer is saying. More information on issues like this and a video on how to perform a power balance test can be found here.

http://www.ericthecarguy.com/faq/solving-automotive-performance-issues

Keep us posted on your progress and good luck.

[apostolis]

Thank you Eric. So today i removed the intake manifold and swapped injectors #3 & #4 and put the intake manifold back together( when i tried to put it back all hell broke loose but later on that) and immediately the scanner showed the code P0204 and P0304( instead of P0203 & P0303) and while the engine was developing a misfire (its was not misfiring all the time) i performed a power balance test which was in complience with the OBD codes and cylinder #4 has the problem now. So i ordered a new injector for 95$ (or 70€) and i am waiting for it to arrive. So about the all hell broke loose thing. When i picked up the intake manifolf from the floor to put it back together it started to drip oil, a lot of it (about 3oz) and when i removed the throttle body a saw that all the interior was covered with oil. Also a rubber gasket between the valve cover and intake manifold was leaking oil and the top of the valve cover was covered in oil-dirt (i applied some gasket sealer when i installed it later). Then because the manifolds interior was covered with oil i thought that it was a good idea :silly: to remove the MAP sensor to clean it. I tried to pull the sensor out and i was very (and i mean VERY) carefull and it BROKE :angry: . The plastic was completely flimsy. Anyway i used some superglue and epoxy as a temporary solution until i get a perlacement part. I cleaned the manifold with brake cleaner and put it back together.
Any ideas why my manifold had so much oil inside?

[EricTheCarGuy]

Oil in the intake is usually an indication of a worn out engine. As an engine wears, blow by increases and the PCV system draws it into the intake. You might do a compression test to see what kind of shape the engine is in.

Also, well done finding the injector problem.

Keep us posted.

[apostolis]

I dont think that the engine is worn, it has only 50k miles on and i do oil and filter changes at 10k miles instead of 20k miles-or 1 year that the service manual says. Also before i go hard on the engine(not very often) i make sure that is compeletely warmed up. The engine burns no oil at all between oil changes (sometimes maybe 3oz at 10k miles, sometimes not at all). I use fully synthetic oil and the recommended viscosity, even the same brand that the manufactures recomends.Is it possible that an engine with this milage and treatment to be worn? Any other causes of oil in the intake manifold?

[Lorrin Barth]

Its up to you but I would check compression because if the bad injector ran its cylinder lean it might have caused damage in that hole. Hopefully, it all check out good.

[Panagiotis]

Hey Apostolis! Long time no see!

What happened to that Clio? Did you come up to a solution with that misfire problem?
And the most important thing… Did you find a honest garage in Athens to make the diagnosis properly BEFORE anyone changing ALL those parts?

[Author]

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