FD3S_wanted

iTrader: (5)

Hi guys,

I have been troubleshooting my boost issue since a few days now. I've searched the forum a lot and I've read this troubleshooting guide 3-4 times: Troubleshooting. Now I'm stuck. I need some inputs from you guys. I have a lapping day next saturday and I would like to resolve this issue before the event.

Some fact about the car:
- During 2012 winter I did a vacuum job using the simplified diagram. I tested all solenoids and used only the good one. I replaced all check valves with the ones from Dale Clark.
- Efini Y pipe.
- Two hallman boost controllers (pre-control and wastegate) replace vacuum lines with pills.
- Boost controller is hooked like Damian's diagram except that the other port of the pre-control and wastegate actuator are capped. See pictures in attachment.
- A few weeks ago I had a good boost pattern 10-8-10.


The problem:
Below 4000 rpm, the car feels a bit sluggish, the boost seems slow to build and won't pass 7 psi. The boost pattern is 7-8-10. I have two hallman boost controllers (no pills). When I try to increase primary boost (pre-control actuator) nothing change, still 7 psi.

Here is the tests I have done following the troubleshooting guide http://www.autosportracetech.com/RX-7/BoostTest.htm:

OK... Nothing to do...

OK. I have removed the Double throttle and installed a block off plate.

OK.

I don't have the 4 psi. I'm a bit sceptical on this one. Does anyone have 4 psi by free reving the engine?

So I start looking for a leak:

I have a efini Y pipe.

I have replaced with new hoses in winter 2012 and I can't turn the hoses by hand.

I have a M2 large SMIC.

This test doesn't seem right. I think pressure should be put through port C to simulate the engine when in boost. Mine doesn't pass this test neither the charge relief valve. However, if I put 10 psi on the port A, both ABV and CRV can hold 15 psi.

Passed.



Back to troubleshooting guide:
I've done only the first two steps since I was alone. First two steps worked correctly.

Passed.

Sorry for the long post but I wanted to share as much info as possible.

So I have 3 questions:

- Do you guys have any idea of what to do next?
- I'm suppose to see 4 psi of boost when just reving the engine?
- Is the 15 psi leak test from the troubleshooting guide to check ABV and CRV correct?

Thanks a lot,

Alex

DaleClark

iTrader: (55)

First off, nice, detailed post! I wish others would take the same care and time sometimes. "MY FD NOT BOOSTIN DAWG, SUP?"

Anyhow, if you're getting low boost on the primary, the possible culprits are -

- Turbo control actuator. If the door is open, the primary turbo will be VERY sluggish to come up. Had a buddy's car with a nicked vacuum line going to the turbo control actuator that was venting either vacuum or boost (there are 2 lines to it, one vacuum, one boost). Make sure those lines are sound and are hooked up right, if they're backwards you'll also get weird stuff.

- Boost leak. Less likely, but always a possibility. The Efini Y-pipe fixes a common problem, but if it's not bolted down flush, gasket is bad, etc. you could have a leak there. More common is the couplers and hoses for the intercooler, TB elbow not on tight (did that one myself once), etc.

- CRV venting when it shouldn't be. Check both BOV's to make sure they're plumbed in right, if they're hooked up improperly they could be venting boost.

Dale

FD3S_wanted

iTrader: (5)

Thanks Dale!

What do you mean by "plumbed in right" ? Like putting the valve in the wrong side (arrow on the valve toward the engine instead of the airbox) ?

BTW I forgot to mention that yesterday I did a roadtest with the ABV and the CRV interchanged. No change at all, still 7-8-10.

chinoflyer

iTrader: (1)

Do you still got the stock rubber intake pipe for your primary turbo? If so make sure they are not bend, twisted, or pinch in any ways for they may collapse when is hot and under load.

chinoflyer

iTrader: (1)

Don't forget the intake elbow. There is the ISC pipe there too.

FD3S_wanted

iTrader: (5)

No I have an upgraded intake box with SS piping. Maybe clogged air filters? I'll have to take a look.

FD3S_wanted

iTrader: (5)

Tonight I continued to troubleshoot the car. I made some progress.

I completed the KOKO test:

The charge control actuator moved each time.
BUT the turbo control actuator didn't move at all and was in position where the flap is closed. Since I can't get 4 psi of boost at neutral like "supposed" to fill the pressure chamber, I put a T between pressure chamber and the check valve and put 10 psi with a pressure pump. KOKO a few times and the actuator still didn't move. Someone knows if this test is valid ?

If the turbo control solenoids were the culprit I guess the flap would stay closed all the time since when the engine is started the flap is closed (at least on my car). Also the car pulls pretty hard after the transition so I would think the flap eventually opens to spool both turbos. However I don't know if the flap closes back when in low rpm. Is this situation possible ? If this is the case that would explain the slow spool.

I tested the turbo control actuator, the pre-control actuator and the wastegate actuator with a vacuum pump. The turbo control and pre-control actuators worked fine. However the wastegate didn't open when putting 10 psi of pressure. There was a leak in the line. I removed the hose and don't ask me how but the wastegate nipple was crushed, the one that connect to the MBC. So my wastegate probably never worked for a while. I have been lucky to not blow the engine.

While in there, I inspected the two Hallman MBCs. Both were totally closed, I mean no pressure were going to the pre-control and wastegate actuator. I turned the MBCs again and again and again in hope to increase the boost but that didn't happen. This means that the pre-control flap was always closed, so no exhaust toward the secondary turbo and more for the primary. So if I have more exhaust in the primary, why only 7 psi ?

Also if the MBC of the wastegate was totally closed (flap always closed), I should had much more than 10 psi of boost and probably blow the engine but fortunately it was not the case.

So I see the following hypothesis:

However I would be suprised because the turbo control actuator is closed at startup and the car pulls pretty strong after the transition so that means that the flap eventually opens. The only way I see this could happens is that the flap never closes back after the first time it opens.

Since the pre-control flap never opened because the MBC didn't let the pressure pass. This means that the secondary turbo never started the pre-spool so if the charge control valve stays open all the time this means that the compressed air would go toward the airbox via the charge relief valve which is opened at lower rpm. However I doubt that this is possible since the charge control actuator moved correctly during the KOKO test.

Possible even if I tested for leak like I explained in the first post. Also I switched the ABV and the CRV and did a roadtest and notice no difference.

With the test I have done, I think this is the most plausible at this time. Tomorrow I will have my setup to test for boost leaks. I will let you know how it comes out.

So Dale all your hypothesis are still on the table.

Your inputs are welcome guys even if I seem to be debating with myself in this post :P

Thanks,

Alex

adam c

iTrader: (2)

If you are achieving 10 psi after transition, you dont have a boost leak. You do have a control problem. I would start by removing the prespool boost controller, and reinserting the oem pill. This should be easy enough to do. Its been my experience that running a boost controller on the prespool line makes boost adjustment very difficult, or impossible. If this doesnt help, You may want to replace the other halman controller too. It sounds like they may both be working improperly.

FD3S_wanted

iTrader: (5)

Effectively the boost leak test was not conclusive. I did have a few minor leaks but nothing important.

I don't have the stock hose with pills. I could test without pills. Without pill, the boost should build up rapidely to 7 psi right?

adam c

iTrader: (2)

You can get the two lines (with pills in them) from any Mazda dealer. I suggest calling Ray Crowe at Malloy Mazda. He will be able to get you the right parts, and get them to you quickly. They cant be very expensive. A search will get you the phone number.

Removing the pill from the wastegate line should give you around 7psi. Removing the prespool pill MAY act to increase the prespool on your secondary turbo. I wouldnt want my car running that way.

FD3S_wanted

iTrader: (5)

Yea I already ordered from Ray in the past. The problem is that I need these for tomorrow.

Anyhow, I tested the turbo control solenoid (the one for the vacuum line with the mitsubishi sign on the cap of the dump port) and the charge relief valve solenoid. Both past the cold test but both failed the hot test. Especially the turbo control that doesn't open at all when I energized the solenoid so the vacuum never goes to the output port. When getting cold, it starts to work correctly.

What's $ucks is that I tested all solenoids two years ago and replaced the faulty ones with good used.

Exidous

As I'm sure you know, hose solenoids are VERY fragile after being under the UIM and two years is more than enough time for a few to cut out. The actuator not working hot almost makes me think of a mechanical issue rather than a solenoid not operating. IE metal expanding and causing gates/actuators to not work.

FYI you will see 4+psi free revving on a good primary. About 10 years ago when I first got into the FD (ignorant) world I bought an FD that passed the 4+psi free rev but I didn't know any better. The secondary turbo was inop........

FD3S_wanted

iTrader: (5)

Ok, fixed the issue. I'm really happy. I have a nice 10-8-10 boost pattern.

I replaced the charge relief valve because it was leaking with a good old one. I re-installed the same turbo control solenoid and I fixed the leaking WG nipple/hose between the boost controller and the WG actuator.

I don't really understand why these fixes corrected a low boost problem. I would have thought that these components were more related to the secondary turbo.

And for the record, I get 4-5 psi of boost in neutral@WOT.

Thanks for the help guys.

FD3S_wanted

iTrader: (5)

For the record, I replaced the charge relief valve solenoid and not the charge relief valve.

Tem120

iTrader: (5)

I'm having very similar issues . But not as drastic ,

At first I will boost slowly BUT will reach 12PSI , By 4k RPM , then transition happens and I hit 14 PSI


Now Before the transition . there is an audible Hiss , after transition the hiss stops and the car feels like someone kicked you in the rear

I've already verified that the turbo control actuator is working as intended . I've checked that the pre control is staying closed .


I took apart teh Y pipe Filled it with water while the divider was closed . and there was some water seepage

But I dont know if this is normal . Or if the Y pipe divider(Charge control valve) is supposed to be air tight .

All couplers are new .

, But the strange thing is if it Is a boost leak , the audible HISS stops after transition .

Which is why I thought maybe I had a defective Y pipe .

it has an adjustment screw Which lets you adjsut how far back it closes and I tried different settings and the leak only got worse .

The BOV has been Blocked off . in exchange for a different BOV and the block off is fine no leaks

so I'm wondering if maybe I have a boost leak from the Y pipe charge control itself leaking boost into the secondary turbo intake .