Code P300 and rough running in the heat

[Davy-Crockettm28]

Recently I’ve noticed that at the higher temps outside 90s to 100 degrees F, my engine has been running roughly. In the past I’ve had to do the fix where you add insulation around one of the injectors due to heat. I’m curious if this heat could be the culprit behind my misfire and how I could go about rectifying the issue. Wether it be replacing the injectors or adding insulation around all of them.

Extra details to add:I recently replaced the TPS with an NGK sensor, and I have not replaced my spark plugs in a while.

 

[TJ Jim]

The complete kit wraps all the injectors and blocks the fuel rail from the heat. I’m thinking you should at least try this before you go much farther

 

[Davy-Crockettm28]

The complete kit wraps all the injectors and blocks the fuel rail from the heat. I’m thinking you should at least try this before you go much farther

Thank you for the info. Is there a mopar version or is aftermarket?

 

[TJ Jim]

I bought this one but it is now double the price. I don’t remember paying this much.
Design Engineering 010378 Fuel Rail and Injector Cover Kit for Jeep (1997-2004, 4.0L Engine) https://www.amazon.com/dp/B015NOKWQY/?tag=wranglerorg-20
Here is one that looks similar but I’ll let you decide which one is best.
010378 Fuel Rail and Injector Cover Kit,Fuel Rail & Injector Heat Shield Kit Compatible with 1997-2004 Jeep Wrangler TJ Grand Cherokee 4.0L Engine https://www.amazon.com/dp/B0BPFR44RN/?tag=wranglerorg-20

 

[Davy-Crockettm28]

I bought this one but it is now double the price. I don’t remember paying this much.
Design Engineering 010378 Fuel Rail and Injector Cover Kit for Jeep (1997-2004, 4.0L Engine) https://www.amazon.com/dp/B015NOKWQY/?tag=wranglerorg-20
Here is one that looks similar but I’ll let you decide which one is best.
010378 Fuel Rail and Injector Cover Kit,Fuel Rail & Injector Heat Shield Kit Compatible with 1997-2004 Jeep Wrangler TJ Grand Cherokee 4.0L Engine https://www.amazon.com/dp/B0BPFR44RN/?tag=wranglerorg-20

For something like this it’s worth it too me to get a better quality one. Have you had any issues the DEI one?

 

[TJ Jim]

For something like this it’s worth it too me to get a better quality one. Have you had any issues the DEI one?

I replaced mine because it was getting flaky and crumbling apart. When I put a new exhaust/intake gasket on, there wasn’t enough left to call it good. I haven’t run into the heat soak problem.
But to answer your question it’s been on for two years and it’s still in good shape and working.

 

[Jerry Bransford]

Any check engine codes besides the P0300? And it runs fine/great when the engine is cold in the morning before it has started to warm up?

 

[duncanator]

Recently I’ve noticed that at the higher temps outside 90s to 100 degrees F, my engine has been running roughly. In the past I’ve had to do the fix where you add insulation around one of the injectors due to heat. I’m curious if this heat could be the culprit behind my misfire and how I could go about rectifying the issue. Wether it be replacing the injectors or adding insulation around all of them.

Extra details to add:I recently replaced the TPS with an NGK sensor, and I have not replaced my spark plugs in a while.

My 01 started throwing the P0300, 301, and 302 codes when over 108 a month ago and I've been researching options too so I will monitor your progress

 

[TexasTJ2004]

I am using the Design Engineering kit. I also have the poison spider louver installed on the hood.
Ran perfectly fine yesterday, when manifold was at 237F (based on IAT sensor in the manifold), and coolant was at 231F.
Before louver and Design Engineering kit, when I would idle when hot it would run rough. If I would shut down the engine and start after five minutes, the heat soak would case multiple misfires similar to what you see.

 

[Davy-Crockettm28]

My 01 started throwing the P0300, 301, and 302 codes when over 108 a month ago and I've been researching options too so I will monitor your progress

It will be about a week until I can get the part, but I’ll try and remember to post my results

 

[duncanator]

So, I installed the kit, cleaned the injectors, and checked the spark plugs and everything looked good. I then took it out a few days ago and the vehicle has been running fine but possibly because it was cooler in 90's. I took it out today since it's hotter (106) and drove it for an hour or so. I then got it home, turned it off for a few minutes, then started it up to pull it in the garage. The Jeep started to idle rough and I didn't have any CEL this time, but definitely a bad performance. I do not smell fuel but the exhaust smell is strong.
I then let it sit in the garage for about 20 minutes and then went out to start it again. It started fine and now has no issues.

Any suggestions? Wrap the exhaust manifold, replace oxygen sensors, or just don't drive it in the heat?

 

[Davy-Crockettm28]

So, I installed the kit, cleaned the injectors, and checked the spark plugs and everything looked good. I then took it out a few days ago and the vehicle has been running fine but possibly because it was cooler in 90's. I took it out today since it's hotter (106) and drove it for an hour or so. I then got it home, turned it off for a few minutes, then started it up to pull it in the garage. The Jeep started to idle rough and I didn't have any CEL this time, but definitely a bad performance. I do not smell fuel but the exhaust smell is strong.
I then let it sit in the garage for about 20 minutes and then went out to start it again. It started fine and now has no issues.

Any suggestions? Wrap the exhaust manifold, replace oxygen sensors, or just don't drive it in the heat?

I’m not the person to ask… but I hope you have luck with it!