P0201 Fuel Injector issue

[lfhoward]

Hi All,

After loading up my groceries at ShopRite, I get in to drive home and get a check engine light, and the engine is running rough. My ScanGauge (and later JScan) indicated P0201, which is an injector issue on cylinder 1 (drivers front). The Scangauge showed 9999 mpg as I limped the Jeep home (only 1/2 mile luckily), so the Jeep is not able to know how much fuel is being used on that cylinder. So far I have no misfires codes but I’m sure they will pop up if I keep driving.

I have the KK service manual and looked at the diagnostic procedure, and got as far as verifying the injector sees 12 volt power when the auto shutdown relay is energized (or the Jeep is running). However, when I removed the two-pin electrical connector from the injector, it smelled like gas in there. There was a residue inside the electrical connector that made it look wet, and smelled like gas. I’m thinking if gas is intruding up into the electrical connector, that injector must be toast, and the gas caused a short circuit. But I’d like to know what you all think. I haven’t gone any further in the diagnosis.

If I need a new injector, Mopar is mandatory here. I have seen too many horror stories on YouTube videos by Eric O., Sherwood, and Dave where customers used non-OEM injectors and it created more problems.

If one is bad, are the other five injectors near death also, or is injector failure mostly independent bad luck? Note, they have 238,000 miles and are original. New Mopar injectors are around $85 each and $500 for a set of 6. The part number for my 2008 KK is 53032701AA.

Thanks in advance,
Lauren

 

[JeepJeepster]

I dont think I would replace all of them if just one is bad.

My 94 ZJ with 275k miles still has the factory fuel injectors...

Eric O would want to verify the circuit before just replacing the fuel injector ya know .. Should be easy enough to check powers and grounds at the connector. I assume the ASD gives it power and the PCM controls the ground side? Complete guess...

 

[lfhoward]

I dont think I would replace all of them if just one is bad.

My 94 ZJ with 275k miles still has the factory fuel injectors...

Eric O would want to verify the circuit before just replacing the fuel injector ya know .. Should be easy enough to check powers and grounds at the connector. I assume the ASD gives it power and the PCM controls the ground side? Complete guess...

Yes, that’s correct on the ASD and the PCM. And you’re right about Eric O. too! I’ve checked the power with the ASD energized and that works. To test the ground side I need to check continuity between the connector and the correct pin (#14) in PCM connector #2. I’m never excited to mess with the PCM but that would be the next step. If that tests good, then checking Ohms on the injector would be next, but if it is leaking gas into the connector then something is definitely not cool with the injector, even if it has the correct resistance.

 

[lfhoward]

You must be registered for see images attach

It’s not a great photo because it’s dark out, but you can see the fuel residue on the connector to injector #1.

The connector to its neighbor, injector #3, is dry.

 

[lfhoward]

This is probably the Jeep’s natural reaction to spending $70 on a tank of fuel minutes before…

 

[lfhoward]

Following up this morning:

The ground side of the connector is continuous with the correct pin on the PCM harness, so we can rule out wiring problems.

The injector itself has 12 ohms of resistance, which is correct. However it has liquid in the connector. After work I’ll put the Jeep on “run” mode (2 clicks of the key) to energize the fuel pump and watch what happens there.

 

[lfhoward]

I cleaned the gas out of the connector area and wiped down the contacts, and turned the key to engage the fuel pump. No additional leaks. Then I reconnected the electrical and started the Jeep. The Jeep ran well for less than a minute and started idling rough again. After turning it off, I unhooked the injector connector again and guess what: it was wet with gas. Apparently the injector only leaks when it is spraying, not when it is sitting still.

I was able to find a new Mopar injector at a local Jeep dealer. Some dealers had it marked up as high as $264, but luckily I got it for half that price. The one I bought was made out of silver rather than solid gold. Online I could find Mopar injectors for about $88 but they won’t get here in time. I need Jeepy running for a trip on Thursday.

 

[eric1514]

I cleaned the gas out of the connector area and wiped down the contacts, and turned the key to engage the fuel pump. No additional leaks. Then I reconnected the electrical and started the Jeep. The Jeep ran well for less than a minute and started idling rough again. After turning it off, I unhooked the injector connector again and guess what: it was wet with gas. Apparently the injector only leaks when it is spraying, not when it is sitting still.

I was able to find a new Mopar injector at a local Jeep dealer. Some dealers had it marked up as high as $264, but luckily I got it for half that price. The one I bought was made out of silver rather than solid gold. Online I could find Mopar injectors for about $88 but they won’t get here in time. I need Jeepy running for a trip on Thursday.

I've never done any work with injectors so I'm just curious, are there some o-ring seals that could be replaced or is the injector cracked or broken in some way to make it unserviceable?

 

[lfhoward]

I've never done any work with injectors so I'm just curious, are there some o-ring seals that could be replaced or is the injector cracked or broken in some way to make it unserviceable?

There are o-rings where the injector seals against the engine on the bottom and the fuel rail at the top. But in this case, the gas seems to be seeping out between the plastic housing and the electrical pins where the harness connects. There isn’t much I can do about that except replace the injector, I’m afraid. I just got a text that my new injector is available to pick up today, so hopefully I am able to do the swap by tomorrow. I’ll take pics and post them here.

 

[lfhoward]

The fuel injector is replaced and she runs! I let it idle up to temperature and revved the engine a few times and no issues. So far no more check engine light. I need to drive it around to know for sure.

I also cleaned the throttle body and as far as I could reach into the intake while I had everything apart. Technically I could have done the #1 injector and left the throttle body on, but it was just really sooty on the back side from the EGR. No doubt the entire intake is carboned up on the inside, but there is no easy way to get to that.

Glad to have a working Jeep again (so far).

 

[lfhoward]

I test drove it for 45 minutes, both city and highway. The engine has good power and idles well too. The Jeep runs smoother than before. I’m calling this one fixed.