P0302 Code

Good afternoon all! I’ve been diagnosing a P0302 code the last few days on my 05 v6. I’ve ruled out coil pack, spark plug and head gasket. Leaning towards injector issue. Any advice on injector trouble shooting or replacement would be most appreciated. If replaced, brand and just replace 1 or all 6?
Greatly appreciate any insight

 

Swap them like you would a coil pack to ensure its not the injector.

You can check them for leaking by jumping the fuel pump relay and watching inside the cylinder #2.

Resistance measurements of coils and injectors are basically useless.

 

Is it possible to swap them without taking intake manifold off? #2 cylinder is issue

what would I be looking for if jumping fuel pump relay?

greatly appreciate insight!

 

Is it a constant misfire?
Or sporadic?

Also, I believe the intake might need to be removed.
The fuel rail needs to be unbolted, as it holds the inject in.
But Bishop84 would know for sure.

 

Sporadic…

that was my assumption on intake. Just weighing worth going to that extreme just to swap rather than replace. But I see the value in swapping to know that was issue.

 

Forgot to add that the sporadic-ness seems to only occur on cold startups or at least hours between starts

 

Its not unheard of for them to leak when old/worn.
@jboudreaux1965 probably knows what brand and type to use

https://www.tacomaworld.com/threads/1gr-fes-fuel-injectors-discoveries.541430/

 

Cold start misfire is usually a slow leaking head gasket. They can be very difficult to diagnose.

The intake has to be removed along with the fuel rail.

Try to lubricate the orings with vasoline, or replace them as needed.

 

Do you ever hear the sound of rushing water coming from under the dash when you start the truck? You can also check for a small leak by removing the radiator cap and hooking an air compressor hose to the cylinder and rotating the crank to close the valves. If you start to hear or see bubbles in the coolant there is a leak. Also, buy one of those $20 USB endoscope cameras of eBay and scope the cylinders. If 6 looks waaay cleaner than the other cylinders you have a leak. Also while your scoping the cylinders if you see pooled liquid you might have a leaky injector.

You most likely have about 15,000 maybe more before it starts leaking bad enough to overheat. If you start to get misfires and CEL pretty often or even if you have your first mild overheat and you just want to buy some more time, buy the expensive version Barr's HG sealer and follow the directions to the letter. It does work, get you at least another 10,000-15,000 miles.

 

If it's only on cold starts and/or after sitting awhile I would suspect a headgasket leak as well, sometimes you may not get overheating and the combustion gas test can show nothing or be inconclusive on very small leaks but they will leak coolant back into the cylinder when they sit.
The easiest way to check for coolant entering the cylinder is to pull the spark plug(s) on the suspect cylinder(s), put pressure in the cooling system with a cooling system tester, let it sit for several hours under pressure, and look in the cylinder for a puddle of coolant.

 

Thats a head gasket leaking the slightest bit. The misfire is caused from a small amount of coolant that has leaked into the cylinder/combustion chamber. The coolant trapped inside the combustion chamber is preventing or retarding the spark from the spark plug from igniting the air/fuel mixture until enough of the coolant has passed through the valves.

This is a common problem with the 2nd gens. Im dealing with exactly the same but in cyl# 4. I'm currently in the process of getting a parts needed list so I can do the head gaskets myself.

 

It just pressurizes the rail without starting the truck.
Where he's going with that I'm not sure.
You can always try some "engine rebuild in a can" and waste $14 if it's a head gasket.

 

Thanks all!! Erased code yesterday. Drove about 60 miles running errands and CEL never came back on. I checked Compression since I had access to a tester and changed plugs while doing that. Compression appears ok
1 - 170
3 - 165
5 - 165
2 - 162 (misfire cyl)
4 - 162
6 - 165

Cranked it up this morning after sitting last night. No misfire yet. If it happens again, I’ll keep investigating the slow leak head gasket.
I don’t have access to a coolant system tester.
thanks again

 

The misfire condition in this situation will only last a few seconds at start up ,long enough until the coolant has left the combustion chamber. I think your HG leak is very new and hasnt developed enough yet to misfire at every start up like what mine is doing. When this misfire occurs it probably won't set a MIL/CEL and probably won't be noticed because of rhe short duration. I would recommend in getting a code reader/scanner that has the ability to read Mode 6 Data and start monitoring your first startups. Mode 6 Data will show faults that have not set a CEL/MIL.

My misfires only will last no more than 5 seconds and very rarely will set a CEL. But going to view the Mode 6 Data I can see which cylinder(3) have the misfire. In my case, its #4

Here is a screen shot of my Mode 6 Data showing cyl #4 having the misfire


With the Fusion APP I can see the misfire happen in real time

 

Send an oil sample to Blackstone, if they detect sodium the oil has been exposed to coolant.

 

All great info. I’m going to scope the cylinders in the morning after sitting all night. I might Send an oil sample after that.

I’ve concluded it’s time to move on to a new vehicle since I travel a good bit. This one has been good for 242k miles. I might Get something out of it

 

Update - scoped troubled cylinder & found dreaded antifreeze.

next step is Barr’s HG sealer as recommended by @jboudreaux1965 to buy extra time to find a new ride & trade in

greatly appreciate everyone’s help. Y’all were spot on!

 

@jboudreaux1965 would you mind sending me link to the exact Barr’s product your are recommending?
Thank you!

 

In the mean time you'll need to keep an eye on the coolant levels. I need to top off every week and a half - two weeks or so, I'm adding about a cup or cup and a halfs worth of coolant whenever I top off

 

Thanks @MonkeyProof !! Appreciate your help!