wierd boost some times backfire and always sputtering

[danyz250f]

Ok here is my long on going problem after putting a evo 3 16g on. I have sputtering and missfireing and once it backfired and threw a big flame. After a long warm up and some stop and go driving I will try to spool a bit and the boost goes up to 10 psi and it seems like there is no power then after a bit it will clrear itself out and start to pull hard at the same 10 psi. Some times it will pull to 6 1/2k good then others especially in 3rd grear around 5k it has its little sputter jerky crapola. Keep in mind this is all at 10 psi on my evo 3 16g and a fmic.

I have done a leak test and it will go up to 18 psi and stop then take like 20 seconds to leak out, and I have a leak that is located around the TB but down low like it is an injector seal. Also could it be a head gasket? I took my injectors out and put some gasket seal on them careful not to get any on the pintle and in the head, I did this because I need new injectors and FIC 650cc injectors come with new seals and I dont want to spend $50 if I dont need to. I also changed my plugs and they looked a little white shouldn't they be chocolate brown. All the plugs looked exactally the same. I have reset my Safc II back to 0 all way across, but after seeing my plugs I put it on the hi throttle pos 5% from 0 - 7k in hopes to put more fuel in to richen it up. I also took my intake manifold off and replaced the gasket and put gasket sealant in the two TB gaskets and got rid of all the vacume lines and capped of the holes. I of corse left the fuel sylinoid line hooked up to the TB and the BOV line hooked up. I aslo blocked off the EGR and used sealant on that and plugged the vacume lines to that. I think this fixed alot of leaks and now my car idles alot better and starts better when its cold. I dont have any coolant in my oil, and oil in my coolant as far as I can tell and I dont have any fluid leaks as I can tell. So I hope it is not a headgasket and the mechanic said the head gasket was fine.

So would buying new 650cc injectors with the three new rubber seals for the injectors fix my problem.

Also my auto meter air/fuel guage when wide open reads the 3rd and 4th bars all the way in in the green, so do I need a new O2 sensor too? When I start to boost at first it feels just like my 2 stroke motorbikes felt after idleing around a long time then pinning it an it runs crappy then all the extra fuel gets burnt up and you take off

I am really frusterated with this problem and have thrown alot of money at it and it still wont go away.

 

[98eclipseRS]

Do a boost leak test at 30psi and make sure it holds 30 psi for 30 seconds. If it won't do that you have boost leaks that need to be fixed. I can garuntee that is your problem. The sputtering is most likely you hitting fuel cut from the maf seeing to much air. Good luck and let us know how its goes.

 

[danyz250f]

It will only go to like 18 psi then stop it will not hold anymore (Alot to do with a leaky tester).

Could there be anything else leaking by the injector seals. I know the intake manifold gasket doesn't leak and the egr doesn't leak and pretty sure but not positive my headgasket doesnt leak.

Also are my spark plugs fine and would 650's fix my problem if it is leaky injector seals. I have spent many hours trying to fix this leak.

 

[98eclipseRS]

It will only go to like 18 psi then stop it will not hold anymore (Alot to do with a leaky tester).

Could there be anything else leaking by the injector seals. I know the intake manifold gasket doesn't leak and the egr doesn't leak and pretty sure but not positive my headgasket doesnt leak.

Also are my spark plugs fine and would 650's fix my problem if it is leaky injector seals. I have spent many hours trying to fix this leak.

Which injector seals are you talking about?? The big plastic looking guys? or the little o-rings that go on the bottom of the injector?? The big plastic guys won't leak they are there to just hold up the fuel rail. If is the small o-rings around the bottomr of the injector they could be leaking and they could be your problem. Putting gasket seal on them won't do anything you need to get new o-rings. Go to mitsubishi and buy new ones, over time they tend to dry and and get brittle and not seal properly anymore. They cost maybe a 2bucks for them and it would eliminate a possible problem. And adding larger injectors won't fix the problem. You need to fix the problem THEN add the larger injectors.

 

[danyz250f]

Ok, Yes I am talking about the seals at the base of the injectors (the ones I think you are talking about are just 3 plastic spacers), I went the the parts store an they have to order them and they were only 5 bucks for all of them but he couldn't tell me what ones they were, meaning the tiny ones inside the fuel rail or the harder ones at the base of the injector. Or the bushing ones in the middle. Plus my injectors can move it isn't that hard to twist them, they alomost feel loose, is this normal?

To buy all the seals it was $12 per injector and that is what it cost my friend for his 87 honda si. So I didnt want to spend 50 bucks then buy the 650cc injectors that I need anyways with a bigger turbo then have this extra set of useless seals.

 

[andrew4g63]

Parts stores in my area could only get the o-rings that went into the rail not the head, I just ordered a new pair from Slowboy racing.

 

[danyz250f]

Well then I will get the o rings first and see how that goes. If anyone knows where to find a part number that would be greatly appreciated so I get the right ones.

 

[ddavisaf]

They're called fuel injector insulators. I don't have a part number for you. www.slowboyracing.com sells them.
What kind of spark plugs are in the vehicle?

When testing you only need to put 20 psi in a near stock system to get accurate results. You want to be able to hold that 20 psi steady for a minimum of 30 seconds.