infinit1

I just got my car done and it is stock with filters and a muffler. I have a putter that comes when I am under boost. I hane no boost gauge so I don't know what the boost level is, but I think I am leaking of boost when it is happening. Has anyone ever had this problem? I also just changed all my vaccum lines.

Flybye

Get a boost gauge then we will talk

Rob Bassett

Ask around but it sounds like a fuel cut off problem. It doesn't really cut the fuel off but shuts the spark off for a fraction of a sec. I found out the hard way myself, I put on exhaust, filters, under-driven pulley and some other stuff. Under power it burps for a sec and then picks back up, if this sounds like your problem then you need to upgrade you ECU. I replaced mine with one from Pettit Racing and the problem went away. Your stock ECU doesn't know what to do with the extra boost your car is producing and yes, just a filter and a muffler can get you more boost. Freeing up the intake and exhaust will get you more boost. The more you free it up the more boost you can get. Lose the air box, get a cat back and an ECU and you will not be able to get rid of the smile on your face. It is a little expensive but well worth the money. You do need to invest in a boost gauge, I recomend a pillar mount because the collum mount covers up part of the tack. If funds are a problem, just try making the holes in the pills a little bigger. I think they are in the vac lines and control the boost level, go a little bigger and see what that does for you. Check on that suggestion because I don't know for sure where the pills are but I have been told that will lower the boost. Bigger the hole the lower the boost, call Pettit Racing, Racing Beat or someone like that. They will be able to help find the pills.

infinit1

I doubt it is a fuel cut because it is incosistant. Although the boost is incossistant throughout the day I still feel that it is something else. I will tryto put on a temp boost gauge for the time being this week but I am sick in bed with the Stomach Flu and you know how that goes. It is a strange thing that happens when it does. It goes under boost at lower RPM(never the same RPM level) then it starts to sputter with a loud sound with it that can be heard in and out of the car. I have never had anything like it before happen to me, but then again I have never messed with a "stock" sequential set-up. Do you know if there is a way to just get rid of all the vacum lines and solenoids for the turbo system? I mean is there anyone that has run the stock twins conventionally with the wastegates hooked up directly and none of the other valves and blow offs.

user 84205

Do you have the stock blow off valves? Do you have
a steady idle?? or is it up and down?? Next if all is
well. Look into your injectors..........Its not fuel cut
for sure.... But with stock computer.... you have a
boost cut too, it works just like a fuel cut. Its just
boost instead

pweizman

If the sputter is at 3000 rpm, it is normal when the car is cold. It gets better as the car warms up.

Patrick

infinit1

I think it may be a vaccum line that I may have missed but I doubt that too. I don't know what it could be but injectors sound like a possibility. I just don't have the time to pull the manifold at the time being. It doen't feel like a cut from the computer but I could be wrong. I am more used to a real cut like a 2 step aor a rev limit from an aftermarket system.

Flybye

Reason why I am suggestion you quickly get the boost gauge is because if it DOESN'T turn out to be boost related, then we can completly rule out anything that is turbo related.

infinit1

Put on a boost gauge today and to no surprise it is going 5-4-2 maybe 3 I don't know. The sputter goes away when the turbo gets hot but the boost level is the same. It idles fine and has a lot of vaccum (15-16in). I am really stumped.

Flybye

Well, if it only goes up to 5 on the first turbo, then your first order is to look for a boost leak. Here are the main points to check:

1) Rubber coupling above y-pipe (You need to remove it. A Visual usually doesn't help to see if it is split)
2) Both rubber couplings attached to the intercooler.
3) Loose intake elbow attached to upper intake
4) Check for cracks on the IC itself.
5) Check for cracks on the upper pipe (from y-pipe to IC) for cracks

If you dont find the problem there, then you may have to:
1) Check all hoses going to the wastegate and check wastegate actuator function
2) Check for bad and sticking BOVs
3) Check for broken hoses attached to the BOVs

Ok get to work

infinit1

I am going to check all that out this week but I also need to figure out what the noise is. Do you know what it is? What does it sound like if the second turbo is blown?

Flybye

The sputtering could very well be the rubber coupling flapping itself back and fource. Wouldn't be the first time its happened...

infinit1

I found the sound! It has nothing to do with the turbos at all! I still have a 5-4-4 pattern of boost though. I checked all of those things but still nothing. I guess I will never see full potential of the stock set up. I would never of been happy with it anyway. I was just trying to get some more power out of the stock set up while I get parts for the single. I guess this will just make me build the single faster. Does anyone know of a good header that isn't stupid expensive?