turbo install time!

[VelocitàPaola]

Yeah, that's one of my FCDs then...

 

[dsmclipse97]

well it looks like i will need to make myself a boost leak tester, bust out a bottle of soapy water and start testing vacuum lines. Im going to also need to tune the FCD anyways because i was screwing around with it. I will also be pulling the plugs, check for fouling and replace them with a new set of NGK-6's. I still have OEM rated plugs installed which could be part of the problem.

 

[totaleclipse_05]

well it looks like i will need to make myself a boost leak tester, bust out a bottle of soapy water and start testing vacuum lines. Im going to also need to tune the FCD anyways because i was screwing around with it. I will also be pulling the plugs, check for fouling and replace them with a new set of NGK-6's. I still have OEM rated plugs installed which could be part of the problem.

A boost leak on our cars shouldn't make it run like crap, we use a MAP sensor in the intake manifold where it measures the air there, not in the intake with a MAF sensor like a 4G63 uses. I would shoot for 4.5-4.6v for the FCD voltages. On my old RS, I had it set for 4.61v and a ran great, but when I swapped it over to my talon, it didn't run right. I lowered it to 4.51v and runs like a champ now. I would go with the step colder spark plugs for a turbo application as well and gap them to .28-.32 Let us know how it all works out

 

[dsmclipse97]

A boost leak on our cars shouldn't make it run like crap, we use a MAP sensor in the intake manifold where it measures the air there, not in the intake with a MAF sensor like a 4G63 uses. I would shoot for 4.5-4.6v for the FCD voltages. On my old RS, I had it set for 4.61v and a ran great, but when I swapped it over to my talon, it didn't run right. I lowered it to 4.51v and runs like a champ now. I would go with the step colder spark plugs for a turbo application as well and gap them to .28-.32 Let us know how it all works out

so a vacuum leak wouldnt cause the car to stumble? well i need to fix any leaks i have anyways in order to tune my FCD. ill let you guys know as soon as i can get home.

 

[4UH8ERS]

so a vacuum leak wouldnt cause the car to stumble? well i need to fix any leaks i have anyways in order to tune my FCD. ill let you guys know as soon as i can get home.

You do realize that a boost leak and a Vacuum leak are 2 different things right?
if not pm me and I'll be happy to explain it to you.

 

[dsmclipse97]

You do realize that a boost leak and a Vacuum leak are 2 different things right?
if not pm me and I'll be happy to explain it to you.

Yes, but in order to find either a boost leak or a vacuum leak you need to run a boost leak test to find them right? And this is done by pressurizing the intake tract from the turbo? Please remember that i have done months of research but have very little practical knowledge in turbocharging as ive never done it before and am not working with anyone who has. Thanks for pointing that out 4UH8ERS.

 

[Locke]

Leaking boost only sucks for us because the turbo is building pressure that we aren't using. Otherwise, doesn't really affect us, in the way it plagues the 4g63 guys. (lucky us)

It would be more simple to check for vacuum leaks in a conventional manner.

 

[4UH8ERS]

Yes, but in order to find either a boost leak or a vacuum leak you need to run a boost leak test to find them right? .

vacuum leak-----happens under negative pressure
boost leak--------happens during positive pressure

You can simply check vacuum leaks with some soapy water while your car is idling. I mean 18-20psi of negative vacuum is pleanty to detect the leak .

although, If you have a vacuum leak of the manifold under negative (vacuum) pressure, it can turn into a boost leak under boost, so i guess if you wanted to knock out 2 birds with one stone then a boost leak test might be a good idea.

And this is done by pressurizing the intake tract from the turbo? Please remember that i have done months of research but have very little practical knowledge in turbocharging as ive never done it before and am not working with anyone who has. Thanks for pointing that out 4UH8ERS.

Boost leaks, depending on where they are coming from can be tricky. You of course have to pressurize the system to check for boost leaks because they are caused by positive pressure. Your BOV might not leak immediatly, it might hold pressure fine until about 6 psi because of a weak diaphram or something. When you do your boost leak test, If you can hear a leak, but can't pinpoint it, use some soapy water solution and you should be able to detect the leak precisely. If the area is not visible, you can use a length of vacuum hose to pinpoint leaks. Just "stick it in your ear", move the hose around, and when you are close you'll hear it.

Hope this helps you out.

 

[dsmclipse97]

yes it does, thanks again. I have also heard that you can use ether or another highly combustible fuel and spray that on the vacuum line connections. If the idle surges than you have a vacuum leak. Just wondering if this method has worked for anyone and it seems cleaner because any excess ether would simply evaporate. But i guess by now we are just beating the issue to death . Ill let you know how it turns out.

 

[dsmclipse97]

BOOOOST!!!! My car is FINALLY seeing boost. It honestly feels like a new car . I did happen to have vacuum leaks that i fixed and my FCD was totally out of tune (my fault) which was giving me some severe fuel cut and i didnt even have the 12v line connected right. Theres still a bunch of work that needs to be done, like my exhaust system, bumper support, any boost leaks and a general clean-up . But all that i can probably do myself and i just wanted to thank all of you who helped me, i really never could have done it without this site.

 

[totaleclipse_05]

BOOOOST!!!! My car is FINALLY seeing boost. It honestly feels like a new car . I did happen to have vacuum leaks that i fixed and my FCD was totally out of tune (my fault) which was giving me some severe fuel cut and i didnt even have the 12v line connected right. Theres still a bunch of work that needs to be done, like my exhaust system, bumper support, any boost leaks and a general clean-up . But all that i can probably do myself and i just wanted to thank all of you who helped me, i really never could have done it without this site.

Good to hear man I remember when I felt boost for the first time, it was a good feeling that I haven't been able to recreate yet. Maybe when I have a built engine down the road and bump up to about 15 psi haha. Take some pics to share here.

 

[dsmclipse97]

ok new problem. my narrowband A/F shows me going lean at WOT and i cant figure out why. i pulled my spark plugs and they seemed fine, not soaked in fuel and they wearnt burnt. But shouldnt i be running really rich with a 12:1 FMU? I should point out that my downpipe has..uh... holes in it and my front o2 sensor isnt sealed into the downpipe very well. I dont know how an o2 sensor functions mechanicaly so i dont know if that would effect it at all. im pretty sure my FMU is hooked up correctly. my wastegate is set at 5psi. thanks for any insight.

 

[VelocitàPaola]

Fix your downpipe. The leaks are letting fresh air get sucked into the mix, which makes the O2 sensor see a much leaner mixture than what is really being pushed out of the exhaust.

 

[dsmclipse97]

Fix your downpipe. The leaks are letting fresh air get sucked into the mix, which makes the O2 sensor see a much leaner mixture than what is really being pushed out of the exhaust.

Good call, i hadnt perceived the downpipe as "sucking" in fresh air. thanks a bunch.

-ill have pictures of the setup as soon as i find my camera-

 

[DSMcrazy3]

How big are the holes? They may or may not be the cause of the problem. If they aren't you could be risking your motor if you continue to boost like that.

 

[dsmclipse97]

the holes are not big, but there are two of them, one before one after the O2 sensor, plus the gap around the sensor itsself. i have been laying off the boost until i figure out what the deal is. my only issue is, shouldnt the spark plugs reek like fuel? i should be pretty rich but my plugs seemed clean. ill check them again, recheck my FMU and try to fix those holes.

 

[totaleclipse_05]

I would check to make sure your vacuum line running to your FMU is good still and doesn't have a hole or anything in the line as well.

 

[DSMcrazy3]

Does it take a little boost to start going lean? Or at WOT period.

And what do you call 'not big'. Dime sized, smaller, pin hole, etc...

 

[dsmclipse97]

well i made the downpipe by wraping steel pipe sliced lengthwise around the two connecting pipes then using an exhaust clamp to tighten that wrap down. id say the holes are less than an inch long and very small height wise. My welder ran out of argon so i couldnt weld it shut. The A/F ratio bounces around alot as normal but at WOT it goes lean, the more i rev, the farther into "lean" i go. im going to weld the DP closed hopefully tonight and pull the plugs again. I will check the vacuum hose to the FMU, make sure there arent any leaks

 

[dsmclipse97]

I should also point out that my A/F gauge is connected to the O2 sensor wires that run along the drivers side of the center console in the cabin. I dont know if these wires run to the front or rear sensor or even if it makes a difference but i thought i might point that out.

 

[VelocitàPaola]

I should also point out that my A/F gauge is connected to the O2 sensor wires that run along the drivers side of the center console in the cabin. I dont know if these wires run to the front or rear sensor or even if it makes a difference but i thought i might point that out.

I'm not sure which specific wire you're talking about, but if it runs to the rear sensor, that would make a huge difference!

Be sure the A/F gauge is connected to the front sensor.

 

[dsmclipse97]

Ill trace the wires tonight, which wires have you guys run your A/F gauges to? And what kind of a difference would having it go to the rear sensor make?

 

[VelocitàPaola]

Ill trace the wires tonight, which wires have you guys run your A/F gauges to? And what kind of a difference would having it go to the rear sensor make?

The front and rear O2 sensors don't output the same information. While the front sensor reports realtime AFR values to the ECU, the rear sensor reports the functionality and efficiency of the catalytic converter. If your catalytic converter is in good shape (as most are), the rear O2 sensor will output a relatively static reading, non-dependent of AFR.

 

[dsmclipse97]

well i found my problem, my FMU is leaking boost pressure through the side gasket, probably from using a table vice on it (dont ask, long story). The leak was enough to make the car run lean but not enough to melt anything. Ill count my blessings. Ill need to order another one this week and ill finally be able to romp on it a little.