speeddemon7

Ok so I cant seem to boost past 9 psi no matter what.
Before the car could hit 15 psi on the stock twins with no problem.Ive searched for boost leaks but I havent found any.Its quite weird because in first the highest I can hit is like 8 psi and at transition the boost drops to almost nothing.Hitting second gear its the same thing.Also the blow off valve barely goes off if for instance I were to let of the throttle and then step on the gas again the car makes almost no boost.I dont understand what could be wrong.Could my twins be finally dying or what?

911GT2

If you're having irregular boost, it sounds more like a control issue than a dead turbos issue.

Have you seen this site yet? http://www.autosportracetech.com/RX-...leshooting.htm It's great for troubleshooting.

If you really wanna find out if it's the turbos acting up or a control issue, you could do the poor-mans non-seq to see if you get good boost then. Search this site for non-seq for a how to write-up.

speeddemon7

Heres some additional info as well.My air pump was making some screeching noises so I disconnected it.
Its been like that for a few months.Could this also be a clogged cat or pre cat?

Mahjik

iTrader: (1)

What mods are on the car?

As the weather gets warmer, you aren't going to have those "cold temperature boost spikes" anymore.

speeddemon7

blitz intake and blitz nur spec catback.
Ive just recently ordered a downpipe.I guess its a good thing.Im seiously thinking its an exhaust restriction.

speeddemon7

I see where youre coming from with the boost spikes.But heres the thing.Yesterday it was cold as hell and the car still wouldnt boost past .6 bar or 9 psi.
Im thinking that with my leaky injectiors making the car run rich and without the air pump the precat or main cat are becoming clogged.

tt2323

clogged cat? you mentioned your airpump has been disconnected for a few months..i just removed my airpump also...pull that sucker out! its very simple. How many miles on the cat?

Mahjik

iTrader: (1)

I'm thinking you were seeing a spike before (which is why you saw it hit up to 15 PSI), but you are still a little low for your normal boost right now as it should be at least 10 PSI.

How do you know your injectors are leaking?

Honestly, disabling the air pump shouldn't cause your cat's to fail, especially that quickly. That doesn't mean you still don't have an exhaust restriction though...

If you ordered a downpipe, install it and see if you still have problems. If you are maxing out at 9 PSI on primary and secondary boost, then it's most likely either a leak up front or a restriction in the rear.

speeddemon7

My thoughts exactly.The car does have 108,000 miles on the odometer.I also noticed that the car has been bottomed out.Because the main cat is slightly dented.Which could mean that the cat is damaged.Im going to change the precat out first and see if that fixes it.If it still doesnt fix the problem I was wondering if muffler shops have a way of testing for clogged cats.For example checking backpressure.Im not smelling a rotten egg smell but I am smelling fuel.Not as strong as it used to be before I changed out my injectors.When I changed out the injectors three of them had hairline fractures in them.Im also thinking that the acv system could be also at fault.Could the ACV have anything to do with my symptoms?
I was also thinking of pressure checking the system.Im still trying to figure out how im going to do this.

speeddemon7

I know this may sound stupid but here goes anyways.The throttle position sensor is out of calibration,I know because i messed with it and havent had a chance to recalibrate it.I know its a long shot but could the tps be causing this? I know its doubtfull but you never know.If this doesnt end up being an exhaust restriction issue Im beginning to see why most fd owners go single turbo.
Some of the other symptoms are serious loss of power,
a whole lot of my torque is missing.The car seems to redline faster.For example second gear now redlines at about 65mph instead of 80mph like it used to.3rd gear now redlines at 120mph instead of still climbing past 130 mph and still not redlined yet.Oh by the way the cars an auto.Taller gears.
The main thing is that at transition boost really drops off and then the car cant seem to build the little boost that it can back up.Ill try to really get some constant results to help pinpoint the problem.

J.S.J

As a tune up and drive-ability tech I had to test a lot of cat's, they were General Motors parts but I don't think would make much difference. I would drill a hole in the system prior to the cat .Using a small drill bit, then place a pressure gage with a silicone type rubber "O" ring or something to hold back the leaks for a few seconds. Hold the engine at 3k and look for a pressure reading. Most often there would be less than one pound of pressure, In fact the needle would not move much at all. The ones under 1/2 psi normally are fine. When you have a real bad one it clear but something on the fence might read a pound. We had special rivets to fill the hole up. I would be sure the boost gage is correct. I used a adapter that you use to air up basket ***** etc. Run it to a pressure gage. If your boost gage is good use that. You could always fit something in the O2 sensor hole, home depot made? The important thing is to hold the rpm steady at the rpm, you may wish to push it to 5k and see the reading??