High idle after replacing cylinder one fuel injector

LOREN STOVER

MEMBER
2003 DODGE INTREPID
2.7L
6 CYL
2WD
AUTOMATIC
234,000 MILES

Car is idling almost at 2,000 RPMs this is after replacing cylinder 1 fuel injector and I have a small evaporative leak and cannot find it. Other than that the car runs great. When I put it in reverse and drive and it's not missing or anything and does not shift hard. It's very smooth going down the road or interstate. It just idles really high in park.

7 Replies

LOREN STOVER

MEMBER
130 POSTS

These are the codes I got today it just took a little while after I installed the injector because I had to reset the computer.

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Saturday, July 24th, 2021 AT 6:33 PM

JACOBANDNICKOLAS

MECHANIC
108,117 POSTS

Hi,

The two codes are related to two different things. The evap leak (small leak) can be something as simple as a bad fuel cap. Remove the cap and make sure there is no rust or corrosion around the top of the filler neck. If that all looks good and the cap is good, I recommend having the EVAP system smoke tested.

Basically, smoke is injected into the EVAP system at a very low pressure. If there is a leak, the smoke will come out at that point. I suggest this because if there is a crack in a hose or something other that is similar, it will be very difficult to find.

The idea that the EVAP code could cause a "small" vacuum leak could cause an idle issue.

Next, the idle air control performance is related to the high idle. The IAC valve is responsible for maintaining engine idle speed.

I attached the diagnostics for the P0519 below. Let me know if it is something you are comfortable trying. Also, please feel free to let me know if you have questions or need help with something.

Also, here is a link that explains how to service an IAC:

https://www.2carpros.com/articles/idle-air-control-valve-service

Take care,

Joe

See pics below.

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Saturday, July 24th, 2021 AT 8:48 PM

LOREN STOVER

MEMBER
130 POSTS

I'm not sure I understand what you mean by good trip counter, but when I change the fuel injector I had to take the plenum off. So do you think maybe the plenum gaskets are the root cause for my high idle? As for the EVAP system I can't do a smoke test right now, but when I went to fill the tank at the gas station the neck going to the tank filled so fast that the gas pump shut-off. I'm not sure that would be related to the small leak but it doesn't hurt to ask.

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Wednesday, July 28th, 2021 AT 7:03 AM

LOREN STOVER

MEMBER
130 POSTS

I sprayed brake parts cleaner underneath the plenum and it change the idle on my car that's after I replaced the plenum gaskets. If I have leaky O-rings on my injectors can that cause high idle or other words can it cause an idle air control valve code?

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Wednesday, July 28th, 2021 AT 5:02 PM

JACOBANDNICKOLAS

MECHANIC
108,117 POSTS

Hi,

If you have a leak on one of the o-rings on the injectors, it would be leaking fuel. If the idle changed, it sounds like you have an engine vacuum leak. That would also help explain the EVAP leak.

If there is a leak, and it sounds like there is, you will be getting unmetered air into the combustion chamber. That will cause a lean mixture and the computer to try to compensate. That can cause idle issues.

See if you can locate where the leak is. Note: be careful when spraying parts cleaner on a hot engine. It is flammable.

Let me know if you are able to locate the leak.

Joe