Steady then blinking engine light

[jpasquini]

Yep, those rubber rings are $25 apiece to replace and the injector itself is over $70. "Special order", gotta wait till Monday due to Holidays.
So this is a dangerous game for the light of wallet......
I'm going to try using it as-is and hope it doesn't leak. It doesn't look too bad.
Ended up finding a product called "Dielectric Spark Plug Boot Protector, Locks out Moisture".
I'm going to try rolling the dice using that to lubricate the rings, to help get them in.
As Indiana Jones said, "I'm making this up as I go along". Stand by for updates, explosions, etc

 

[jpasquini]

Well, disaster.
I started the engine up and both #4 and #6 are leaking fuel all over the place.
Apparently that lubricant was a no-go.
And now its dark out, and below freezing outside and I have no vehicle.
Aren't you all lucky, you aren't me

 

[Blondie70]

Cheer up. It's New Years. And, after you conquer these injectors, I am betting you will be the resident injector expert !!!!! At least, you will know more than me....which aint much..ha ha.
You will beat them. You will be cruising around with a smooth engine soon.

 

[jpasquini]

I had got it Weird that Auto Zone said the injector rubber rings were $25, I got some at O'Reilleys for only a few dollars.
Only this time I disconnected the fuel line and took the whole fuel 'coil' out.
Replaced the rings and used Aquaphor instead (its basically petroleum jelly, but didn't have that). It was much easier.
Started it up and it is running dry as can be. I reset the car battery and drove around for about a day, with no engine light at all.
But alas, I was not to get off so easy.
The following day, engine light popped on again steady, and finally once again, started blinking every few minutes just as before.
Even though I switched fuel injector #4 with #6. There is only one error code: P0304, Cylinder #4 misfire. Same as always.
Can't be the fuel injector then, right? After all, same error.

I tried this multimeter test on the fuel injector plugs, set to 200 ohms as he says. But I'm getting no reading on any of them.
I'm assuming it needs to be check with the car off, or I'll be blown and shocked?

What is this Compression test, spoken of earlier? I suppose that is the next step.

 

[jpasquini]

OK so the results are IN on the Compression test and we may finally have an answer to the incredible Cylinder 4 Misfire puzzle.
I was able to test the spark plug sockets for 2-6. The Jeep R&D designers, in their wisdom, made the 1st spark plug socket at an angle and impossible to get the compression tester screwed in. What's more, the angle cracked the spark plug taking it out. So thank you Jeep factory engineers.

At any rate, here's what I found out:
5, 2, and 1 all were at 150
3 was just a bit under 150
and the infamous cylinder 4 was just under 120. Quite a bit less.

So. What's my sentence. Or should I start looking through Google.
And the big question is.... if I now have to buy a new engine. How long can I drive the vehicle until then with my "imminent danger" blinking light. Because I have many crises to attend to.

 

[tr21triton]

i doubt you need a new engine probably just a valve job or head gasket

 

[jpasquini]

i doubt you need a new engine probably just a valve job or head gasket

is this where I need to do a leak test?
As far as valve job or head gasket, how hard to do on your own? Otherwise I would just take it to a mechanic if it didn't cost a fortune.

 

[flyinfish]

is this where I need to do a leak test?
As far as valve job or head gasket, how hard to do on your own? Otherwise I would just take it to a mechanic if it didn't cost a fortune.

Try putting a teaspoon of oil into low compression cylinder and run wet compression check. If the compression comes up, the piston rings are not sealing well. If the compression doesn't change, then it points toward intake or exhaust valve. Do a second wet test making sure to rotate crankshaft six times before reading compression.

A valve job requires a valve grind machine and I'm pretty sure you don't have one of those hanging around. Pulling the cylinder head is dependent on your skill level and you may want to take it to an engine guy to do.
Lastly, if it's your only rig, you'll be without it to do repairs and it will certainly cost you more than an injector.

 

[R.Flores]

JPasquini, check Amazon for 4 hole type and replace all. They are inexpensive based on the price you state for a single one. Also, you can use petroleum gel for easy insertion. You also take a look at the throttle body for cleanliness.

 

[tr21triton]

i bought 4 hole injectors from k suspension for my last 4cyl. their prices weren't bad.

 

[jpasquini]

I don't know if that's what I need yet.
I'm assuming what I need to do next is a cylinder leak down test. But I can't find the how-to procedure on YouTube for a 4.0 2002 Jeep Wrangler, or anything close enough. Has anyone seen one?

 

[jeepins]

"Jeep Wrangler Cylinder Leak Down Test" 2nd video that came up.

Cylinder Leak Down with Low Compression