Been troubleshooting an FD, and it's been stumping me.

Start the car and go for a drive, seems to pull fine on the first run, or at least in first gear. Next pull or when you get into second gear, you get little to no boost on the secondary - like 1 psi, car is a dog.

Car is very near stock - stock ECU, downpipe, intake, stock cat and cat-back.

When you let off the gas at high RPM with no boost, you get a "BYEW!" sound. It sounds JUST like the cheesy sound from old disco songs.

The only problem I've 100% identified is the pressure chamber doesn't seem to be holding pressure. The check valve is good, but the solenoid it's connected to seems to be leaking down.

Anyone had this same problem? Did some searching, found some people with similar problems but no solution.

Thanks guys!

Dale

 

.. reminds me of that movie Boogie Nights!!

but maybe test the solenoid so you know for sure? whats the condition of the car? Maybe some reliability mods might fix it or at the least expose a more identifiable problem?

Sorry to ask you more questions?!

 

any luck dale?

I seem to have a similar problem ever since my sequential simplification.
It only happens sometimes but is very similar to what you are describing.

 

It sounds like you have already found two possible sources of the problem. Fix what you know is wrong, and see if the problem goes away.

Its been my experience that bad solenoids, and bad check valves cause a lot more boost problems than bad turbos.

 

man i have exactly the same problem with that retarded disco sound! i was jus wondering how i would explain the BHEYW! sound and i came across this topic.

oh and sorry im noob so what solenoid do i check...i have a RHD 99 spec engine!

 

anyone? i still cant figure out whats wrong! ive checked all the vacume pipes other then the ones under the UIM!

 

It is the flapper in the y-pipe from the secondary turbo. I had this problem and had crossed up the vacuum line going to its actuator with another.

Jack

 

hmmm ok ill take a look see tom morning, BUT i havent changed any vacume lines! so could a leaking vacume line cause the same thing to happen?

 

+1

 

I've recently had the same problem with the same weird noise. Took me quite some time to track down - turned out to be the charge control actuator attached to the Y-pipe - the actuator barely moved (diaphragm inside was likely worn out and losing vacuum). Put in another CCA, and presto, disco noise gone.....full boost back.

To check if the CCA is working, take the vaccum line off the acutator, push the rod in, and then put your finger over the nipple. If the rod retracts while you have your finger over the nipple, you have a leak and you need another CCA.

 

Mine had the little C clip come off the actuator arm/flapper pin connection.

Dont take it a dealer. I had an rx7 guy at my dealer but he wasnt there the day I brought my car in. Cliffs notes: Some rookie quoted me new turbos saying mine were blown. I knew better and took it elsewhere and saved 3500 bucks.

 

BUMP +1000! I have exactly the same problem and made/posted on similar threads concerning this. Anyone with a photo or diagram of said areas and parts to check?

 

Nevermind about the CCA. I think I found and located it using the vacuum hose diagram. Is the flapper in the actuator or in the y pipe?

 

As others have said, this sound is likely the result of the flapper in the Y-pipe being open as the primary spools. What you're hearing would ordinarily be surging against the turbos, but because the secondary is not spinning (and why would it at this point?) there is a path of no resistance to the charge surge, and therefore no flutter.

Take your intake pipes and air pump off. Run the car at idle and have a look at the actuator arm. If it is floating (and therefore not closed) at idle, the diaphragm is leaking or torn, and you need to replace the CC pipe.

 

Diagnose the charge control actuator first ,that takes place of you secondary transition on your tubocharger.Check fd3s.net and look at the 93 manual its under sequential trouble shooting !That manual helps alout check it out man you be glad you did.

 

wow alot of feedback! thanks guys! ill check on actuator tom, although i did fiddle around with it a lil bit when the car was off, the arm was moving pretty freely!

 

ok so i checked the actuator today....seems to be working fine! the arm is all the way in during idle, i even pulled it out, it goes back in right away! i guess ive reached another dead end

 

Wow, very interesting stuff here! I'm curious to see how this all turns out. What did you find dale? Let us know!

--Hank

 

Take the couplers off the crossover tube/intercooler, and make sure they are not torn.

 

i checked n doubble checked!

 

Check the solenoid that controls it... If I remember correctly its one of the two that are up at the top where the intake begins to curve down. Be extra careful as those nipples like to break off!

Its been a while since I had twins so i may be wrong!

 

Telltale sign is the boost guage will zero out on throttle and stay at 0. Mine did when I split one of the accordian couplers.

 

the funny thing is when i had my PFC for a week or two, the boost was fine. i took it off and put the stock ECU on...and i get 0 boost. the small coupler at the intercooler was slightly torn......SO i changed it and i have been having these boost issues ever since.

1st gear i get 10 psi for a sec and then its down to 4
2nd hits 10 for half a second then its 0 boost in all gears, pumping the throttle dosnt help either!

 

u sure u put the coupler back on all the way, maybe its leaking under boost.

 

man i check that damn coupler everytime hoping its the apparent problem, but NO nothig is simple when it comes to these damn rotaries!