Broken Valve Spring

[sybrite]

Originally Posted by rosol16

See if you can rent a boroscope from somewhere or find a shop that has one. This was the only way we found out my valve was burnt without taking the who engine apart

I'm going to try this first. Way better than the cost to take it apart.

[cdrazic93]

so if compression tests intake valves and a vacuum test checks exhaust valves, isnt that leading to the exhaust valve specifically on cyl 4?

[Spartarus]

Originally Posted by cdrazic93

so if compression tests intake valves and a vacuum test checks exhaust valves, isnt that leading to the exhaust valve specifically on cyl 4?

Compression test tests all 4 valves.

Compression will be bad if any valve is bad.

[FRS Justin]

If you suspect carbon build up get one gallon of 93 and one bottle of techron mix together I suggest top cylinder cleaner from BG. Anyway disconnect fuel pump via relay or fuse. So get a fuel injector cleaner some parts store like Oreilly or autozone rent them. Set air pressure to 55psi and let car idle. Then on the second tank rev the engine to 3000rpm. You can connect the cleaner thru the line under the hood. Or just pay the dealer to do it. If that doesn't help you can pull the intake and exhaust to check the valves. Get a bore scope and hand rotate the engine over until the valves are wide open and inspect the valves and seats.
You should also consider bad gas in the tank. That's the mechanical side of it.
If these options don't fix the problems, You should check fuel pressure, and the port injectors.

[rosol16]

Originally Posted by sybrite

I'm going to try this first. Way better than the cost to take it apart.

They aren't all that expensive to buy if you need to and you can probably just snake it in the through the spark plug hole. It worked on my srt4 but different engine config on these so not sure if you can but for the easiest way and cheapest way to know for sure

[sybrite]

Update

Finally allowed the dealer to do there troubleshooting which freaking cost waaaay to much IMO.

He ran a signal test from the ECU and all the signals were good.
He did the compression/leak down check and said the compression was good.
powers and grounds were good
Fuel pressure was goodHe swapped the port injectors and the problem remained at cylinder 4.
He wanted to swap the direct injectors but said the guys on the tech line recommended against that because I guess they have to swap everything everything because of the high pressure or whatever.

So process of elimination he believes that the direct injector needs to be replaced.

[Spartarus]

He is correct. Just to pull them out and inspect them, you need a couple hundred dollars in parts. This video explains why nicely. It's a bit old.

Not entirely relevant, because your seals are most likely not bad. If they were bad, a compression test would likely reveal. But it does show removing and replacing them, and the problems associated...

[ame="https://www.youtube.com/watch?v=sdeO4rBwuQ4"]Scion FR-S BRZ Direct Injector Seal Replacement | Problems and Issues - YouTube[/ame]

Take a look for curiosity's sake.

[RavioliG]

Oh my god I have nearly the same exact problem.
Dealer said compression was fine, and then replaced my HPFP.
http://www.ft86club.com/forums/showthread.php?t=99994

After three weeks the dealership gave up on me.. "We no longer can diagnose your vehicle. At this time we would just start replacing parts on your dime, until the problem is fixed, at which point warranty will cover that one part"

This is when I took my car home, thinking what a load of BS. (Car is still under warranty..)
My next step was to pull all my injectors, PI and DI, and get them sent to get flow tested and cleaned so please keep the updates coming!

[Toyarzee]

Originally Posted by RavioliG

After three weeks the dealership gave up on me.. "We no longer can diagnose your vehicle. At this time we would just start replacing parts on your dime, until the problem is fixed, at which point warranty will cover that one part"

How in the hell does that become an acceptable solution in their book?

[sybrite]

Originally Posted by Spartarus

He is correct. Just to pull them out and inspect them, you need a couple hundred dollars in parts. This video explains why nicely. It's a bit old.

Not entirely relevant, because your seals are most likely not bad. If they were bad, a compression test would likely reveal. But it does show removing and replacing them, and the problems associated...

Take a look for curiosity's sake.

Thanks for the video. That really puts this repair into perspective. Hopefully this will fix it and there won't be any other problems with it going forward.

Does leave me curious as to if this one went bad, what is the likelihood of the other three going bad? Was it a fluke occurance or maybe just stem from a factory defect.

[Spartarus]

Originally Posted by sybrite

Thanks for the video. That really puts this repair into perspective. Hopefully this will fix it and there won't be any other problems with it going forward.

Does leave me curious as to if this one went bad, what is the likelihood of the other three going bad? Was it a fluke occurance or maybe just stem from a factory defect.

Always happy to help.

The likelihood of a direct injector just "failing" is very low, and likely due to a manufacturing defect not present in the others.

While I hope the direct injector is the problem, it's no guarantee. If they are wrong, there are still other valid possibilities, and you're back to (what amounts to) playing whack-a-mole, blindfolded, at your own expense.

Good luck.

Originally Posted by Toyarzee

How in the hell does that become an acceptable solution in their book?

I hate dealers.

Oh, the joys of being out-of-warranty. That's why I just voided mine and saved the trouble of feeling ripped off when they inevitably failed to honor it...

...Though, admittedly, that course of action comes with its own problems.

[sybrite]

Well crud. Looks like the direct injector didn't resolve the issue

He has checked pretty much everything it could be not related to a valve problem. Now I'm just hoping it's more like a gunked up or weak valve spring and nothing worse.

[justatroll]

Originally Posted by RavioliG

After three weeks the dealership gave up on me.. "We no longer can diagnose your vehicle. At this time we would just start replacing parts on your dime, until the problem is fixed, at which point warranty will cover that one part"!

In my state, if I took the car back three times and got that answer each time, they would own it.
My father returned a car in CO on the Lemon Law and got back every penny.
So he drove a 300ZX for 50k miles for free.

[thomasmryan]

is it possible you have an intake manifold leak?