The car seems good in 3-5th gear, and pulls very strong with full boost.

1st gear seems to have a slight problem...doesn't reach full boost. But it still goes by fairly fast.
2nd gear is horrible. It seems slower then normal up till transition, and then after transition it seems like I am bleeding off all boost. The car just falls flat and seriously struggles to get up to redline...if it can make it at all. It is sooooo bad that I havn't chanced abusing it all the way to 7800 because that is how slow it rises.
I can't hear anything leaking, and the other gears past 2nd are fine throughout. I checked all my vac lines, and the car pulls 15lbs in 3rd gear no problem.

Any suggestions.....my computer is a PFS PMS.


Thanks, Raj

 

alright well i think you should try 3 quarter throttling...its when you push the peddle three quarters to the floor ...most turbocharged cars pull harder and more effectively at three quarter throttle...so just try not to get a heavy foot and it might clear up the low boost problem in second gear...i know it helped me a lot well good luck and peace out

 

What's the boost pattern in the first 2 gears? If you can see it.

I kind of have the same problem, but boost set around 10-11.

 

care to elaborate on this notion?!?

 

you said "won't reach full boost", what do you have full boost set at? my old roommate has a friend who runs a turbo miata in Chicago, and when he goes for top speed runs (dangerous, don't know the guy so i can't really do anything about it), his boost controller beeps at him and cuts boost because he is overboosting, but when he goes 1/2 to 3/4 throttle he can keep on accelerating

 

you are seriously running 15 on stock injectors 93 octane?

 

dp

 

I will try the non WOT, but there is a problem with that too.
My fuel maps don't switch to the WOT maps untill I do. So you guys are suggesting to run my normal boost with just my Heavy Throttle maps? That increases my lean-run chances.

What else, this can't be unique to my car.

Raj

 

Are you seq or non-seq?

Edit: dumb question, sorry. PFS, you're probably seq.

If I remember right from my reading, 2nd gear boost issues happen occasionally because the transition is so instant (especially with modded cars) that the vacuum and pressure doesn't have time to get to where it needs to be to open things like the CCV.

Have you checked out this site: http://www.autosportracetech.com/RX-...leshooting.htm ?

 

Thanks 911. I have seen that site, but helpfull none the less.

I am Seq.

Could this be my ignition breaking up? I don't know what that feels like, but in my situation the car gets very hesitant to rise in its rpms in second gear.

Raj

 

Got a better read today.
Checked my ypipe coupler and intercooler connections..they are all good. Checked my one way valve on the vac box..it is good.

This problem seems to be all after transition and the boost is just leaking somewhere. So, full boost upto 4500 and then after it doesn't recover and sits around 3 lbs.

What else? It could be my vac box, I will check that today.

This is making a brotha want to go non-seq!!

Raj

 

Check the Vanditmar site again - the TCA is about 5/8 way down, and sounds similar to your problems.

What kind of hoses do you have? The vacuum side hose may be collapsing if engine oil has softened a silicone hose, or maybe something under the car nicked either one.

Dave

 

Have you tried the standard method of checking the TCA? Theres actually two methods.
[list=1][*]Get the engine up to above 4500 rpm without boost, then nail it and see if you get full boost on the secondary. If you do, it's likely that theres a problem with the TCA or one of the solenoids or chambers that control it. Basically this forces the TCA to see a whole lot of vacuum and then boost, and it needs both to open.[*]Go WOT up to about 5k+ rpm, then quickly jump off and back on the throttle. If you get full boost after you do the jump off/on, again it's likely that theres a TCA problem, for the same reasons described above.[/list=1]

 

OK, I see where you guys are pointing...the Pre Control Actuator (correct?) The symptoms seem exactly like mine, so I should start looking there.

I will check it today. I know my Profec B lines are down there somewhere too, I can't remember where though.

I will check the lines for leaks and replace/retighten them.

Raj

 

dp

 

Damn forum. Do the database administrators ever try to post a picture?

Anyway:

I was talking about the Turbo Control Actuator, the big actuator under the turbos, toward the center of the bay. It is actuated by a combination of vacuum and pressure, and if one side isn't functioning, it have this symptom: "A typical problem is loss of Secondary boost in 1st or 2nd gear at 4,500 RPM, but reliable operation in other gears.". You'll see it on the page right beside this picture: (c'mon forum...)

[edit: errors galore with picture. picture a small soda can with a hose at each end and a rod]

Dave

 

I just saw it..and news to me that there is another vac chamber next to the PS pump!

I will go across those lines and report back on this thread.

Thanks guys...Dave and 911 really showed me the way.

Raj

 

God help your soul should you decide you need to replace that one. It's buried.

FWIW, I think the vacuum tester is a good idea - I just bought one. If you choose to buy one, get the Mityvac Vacuum / Pressure pump. Make sure it can do 15psi pressure, and that the dial reads the pressure as well as vacuum. The cheaper models top out at 10-12psi and require T'ing in a pressure gauge. Get the good set (ebay has a lot of them for sale) and be done with it.

Dave

 

If I go non-seq, do I just bypass all this BS? Or will I have to fix those one way valves before doing anything else?

Raj