Injector # 3 heatsoak issue after insulating?

[adventureboss]

Hi everyone,
I have a 2006 TJ with the 4.0. During summer months, I used to have the infamous heatsoak issue on injector # 3. I did what the factory and this forum recommended by getting the ignition coil boot and insulating injector # 3 with it, however it seems to have made no difference. I never have an issue on short trips, however when I'm driving 5-6 hours or more and then shut the engine off and turn it back on, the engine idles rough for a little bit. The insulator sleeve didn't help with this.

Recently, it's started happening even when it's cold outside and I go for extended drives. I think it's getting worse. This morning, I turned the Jeep on and got a P0303 code. Could my injector just have gone bad? At 184k miles, they are getting up there in age. The cooling system is in good shape, spark plugs were changed less than 10k miles ago with the Autolite XP985, and I've already done the recommended insulation on that injector. Last I checked compression, the engine was in good shape too.

So is it likely the fuel injectors? Maybe ignition coil? But I have a waste spark system, so if it was ignition coil then I would have misfires on another cylinder too right?

 

[Link]

I have a 2005 with the 4.0. I had an issue with it in the summer. Actually runs fine but did have the P0303 code. I have since added the Design Engineering kit. It shows for 1997-2004 engines but worked just fine on my 2005. I did have to make a cut in the sleeve that wraps the fuel rail but installed perfectly. Have you pulled your injectors? Mine were original and there was some carbon/sludge buildup on the injector tips. When I had it off, I cleaned the injectors and the injector holes completely and then installed new o rings. There was more gunk build up on the #3 injector than the others though the actual tip was reasonably clean. Definitely ran smoother. I didn't like the insulating wrap for the injectors the kit came with so I have ordered the Mopar ignition cable shield and will install that.

I also insulated the fuel lines anywhere it runs near hot exhaust. Figure if I can keep the fuel cooler till it reaches the fuel rail it should work even better. I have some long trips coming up this year with it so we will see how it does.

https://www.amazon.com/dp/B015NOKWQY?tag=wranglerorg-20

https://www.amazon.com/dp/B09MVYZHQD?tag=wranglerorg-20

 

[Ashim]

Hi everyone,
I have a 2006 TJ with the 4.0. During summer months, I used to have the infamous heatsoak issue on injector # 3. I did what the factory and this forum recommended by getting the ignition coil boot and insulating injector # 3 with it, however it seems to have made no difference. I never have an issue on short trips, however when I'm driving 5-6 hours or more and then shut the engine off and turn it back on, the engine idles rough for a little bit. The insulator sleeve didn't help with this.

Recently, it's started happening even when it's cold outside and I go for extended drives. I think it's getting worse. This morning, I turned the Jeep on and got a P0303 code. Could my injector just have gone bad? At 184k miles, they are getting up there in age. The cooling system is in good shape, spark plugs were changed less than 10k miles ago with the Autolite XP985, and I've already done the recommended insulation on that injector. Last I checked compression, the engine was in good shape too.

So is it likely the fuel injectors? Maybe ignition coil? But I have a waste spark system, so if it was ignition coil then I would have misfires on another cylinder too right?

Have you replaced the exhaust manifold shield 53013669AA ? It lays across the openings of the intake manifold. I replaced mine at the same time I added the insulator sleeve.

 

[Link]

Have you replaced the exhaust manifold shield 56028371-AA ? It lays across the openings of the intake manifold. I replaced mine at the same time I added the insulator sleeve.

The part you linked is the ignition cable shield. The DE kit I linked above will include the exhaust manifold shield. Supposedly the 2005-2006 didn't need the shield but I think it's a good idea to have one. Mine had one originally but it was falling apart.

 

[Ashim]

The part you linked is the ignition cable shield. The DE kit I linked above will include the exhaust manifold shield. Supposedly the 2005-2006 didn't need the shield but I think it's a good idea to have one. Mine had one originally but it was falling apart.

Sorry, edited, should be 53013669AA

 

[Link]

Sorry, edited, should be 53013669AA

No worries. I saw that one and thought about getting it but I think the DE one might be a little stronger. Not that that part needs to be very strong but that thin area looks problematic. Also, the reviews on Amazon show lots of that part arriving broken.

A previous owner of my Jeep had that same heat shield on mine. It has been falling apart. The DE part has foam insulation sandwiched between the foil but the Mopar part is fiberglass. That's what failed on mine. The fiberglass split. We'll see if the foam lasts better or not.

After seeing both, I think I'd recommend the DE part over the Mopar version but I might change that recommendation after some time! Not sure yet.

 

[dvngdg]

I had the same problem a couple of months ago with the P0303 code. I did the Mopar injector #3 fix, and then changed the new plug. I still had a misfire. I left it at my shop for a couple of weeks, and they noticed my PCM was acting Wonky. They told me to order a new PCM. I changed it and I left the shop with a flashing check engine light. After a couple days of sitting in my driveway, I finally got a P0306 code and a P0174 system lean code . I decided to do a WAG and change the coil rail. That was the WIN for me. So I needed a PCM and a Coil after that. The code and the misfire are both gone !!

 

[adventureboss]

I had the same problem a couple of months ago with the P0303 code. I did the Mopar injector #3 fix, and then changed the new plug. I still had a misfire. I left it at my shop for a couple of weeks, and they noticed my PCM was acting Wonky. They told me to order a new PCM. I changed it and I left the shop with a flashing check engine light. After a couple days of sitting in my driveway, I finally got a P0306 code and a P0174 system lean code . I decided to do a WAG and change the coil rail. That was the WIN for me. So I needed a PCM and a Coil after that. The code and the misfire are both gone !!

Uh oh, hope it's not my PCM as I already replaced it 30k miles ago. Coil rail sounds like a bit of a pain in the ass as well.

 

[adventureboss]

Have you replaced the exhaust manifold shield 53013669AA ? It lays across the openings of the intake manifold. I replaced mine at the same time I added the insulator sleeve.

No I have never replaced it. After I saw your comment I went and took a look, it seems like my original exhaust manifold shield has just deteriorated and parts of it have fallen off. So maybe I'll start there, I'm hoping that's my issue.

 

[dvngdg]

Uh oh, hope it's not my PCM as I already replaced it 30k miles ago. Coil rail sounds like a bit of a pain in the ass as well.

If you decide to to change the coil rail, Gravity is your Friend ! Unbolt the 4 bolts, then flip the coil rail 180 degrees, and use a vise grip to increase the pressure on the wire connector. I was astonished how easy it came out !!

 

[adventureboss]

If you decide to to change the coil rail, Gravity is your Friend ! Unbolt the 4 bolts, then flip the coil rail 180 degrees, and use a vise grip to increase the pressure on the wire connector. I was astonished how easy it came out !!

noted! Haven't had the issue come back in a couple days so I think I'm just going to wait till it starts to warm up and then do the DEI insulation kit