KyleH

I guess you can't edit posts on here?

So, I just want to point out WHICH line I as referring to in the above post. I'm borrowing this one from Dave's site...



That blue line sticking up there is the one that the boost reduction diagram does not mention. Can someone tell me where this line runs to?

Thanks

KyleH

Well, the top hose coming out of the LIM (pass side of the LIM) goes to a nipple right below it down beside the charge relief valve (the dark red line on the diagram).

dgeesaman

iTrader: (7)

No, the dark red line on the diagram connects to the 2nd from top. The orange one goes to the top nipple. (The pass-thrus are simple - it's the same on the side of the LIM that faces you in the diagram).

The free line in this pic goes here:


Dave

KyleH

Thanks for the help Dave.

My esteemed colleague was working on that side. On the nipple that was supposed to be for "orange" line (coming out of the LIM), he had hooked to this nipple a line that ran just a few inches down below to a... what looks like either an FPR, or some sort of EGR piece. So now this "piece" which is attached to the intake manifold it appears, has a vacuum line hooked to nothing. I can't find this part on the vac diagram. Is it okay to just cap it off? Or does it run somewhere. If a picture would help, I can supply, I just unfortunately don't have the abillity to host.

Thanks.

dgeesaman

iTrader: (7)

The EGR valve is the part right below there and mounted to the LIM - I think in the simplified setup it is removed or can be left unconnected. Dunno, my turbo setup is all stock.

Dave

KyleH

Well, thanks Dave.

I took it for a spin. Due to a crack in the coupler for the intercooler pipe, right above the turbo's, I got a temporary fix from autozone. 10psi later, the fix is gone. I guess I'll be ordering a coupler soon enough.

In the mean time, the charge control valve is still not closing at idle, and I can't figure out why. I get no boost until about 4,500, then it comes on strong.

Garsh!

wstrohm

KyleH,

My apology for the "less than insightful" comment on your lack of restrictors. In fact, the ID of the restrictors is calibrated to optimize the response of the first & second turbos. Larger ID leads to sluggish response and lower boost, as I understand it. The 6 mm ID of those hoses is considerably larger than the restrictor IDs.

Regarding your charge control solenoid, there is a test on p. F-177 of my 1994 RX-7 workshop manual. A pic from the manual is attached; hopefully this will help. (You may have the vacuum lines hooked up incorrectly to this solenoid.)

dgeesaman

iTrader: (7)

The CC solenoid plug is white. Ref. the wiring diagram Z-33.

Dave

KyleH

Bill, Dave,

Thanks.

Bill, I have since put a boost controller on the wastegate, and an inline manual valve on the pre-control to make up for my erroneous ways.

I have the boost controller cranked wide open (max boost) and have tried every combination of the valve control with bad results.

With that being said, I can't say anything with certainty at this time, given the massive boost leak (coupler b/w the top of the turbo & Upper I/C pipe is torn badly), other than to say I am still amused at the charge control valve acts the way it does.

I'll dive back into it in a day or two when the new nylon couplers show up.

Dave, thank for the confirmation.

dgeesaman

iTrader: (7)

On the wastegate, smaller orifice size = higher boost. Wide open is about equal to a missing boost pill which limits to 7psi. Remember, when the boost controller / pill / valve is installed in the normal location between the compressor, it serves to 'keep' pressurized air out of the actuator, which reduces the amount the door is opened. Bigger hole or no pill = letting more the pressured air in, which opens the door more and vents off more boost.

The precontrol is extremely sensitive, and not easy to tune. If you can drop in a stock pc pill I would do that until the wastegate is well dialed-in.

In any case, it's not worth worrying about until the couplers are installed.

Dave

KyleH

This boost controller works opposite of normal. Back the screw up and it raises the boost... don't ask, it's only borrowed at the moment b/c of my current predicament.

CantGoStraight

That's what I was going to ask did you keep the pills and put then in the new hoses you replaced. The other questio is did you replace any of the big vacuum lines like the ones to the brake booster ??? Theres a check valve in that one that can give you a problem.

KyleH

Vacuum is all good. No, I didn't replace the large hoses. And yes, I did throw out the pills for the WG/Prespool lines. Hopefully the couplers will be here early next week and I can get back to it.

KyleH

What a difference 6 days makes... or not.

Got the couplers on.

Running from a roll to WOT, @ 4,700 RPM the boost will go from 0-3psi (random) up to 8 psi and then drop back to 2 or so psi by redline. Horrible.

If I "hotwire" the control valve solenoid straight off the T that should run to the charge control solenoid, then the valve will "shut" at idle, allowing me to spool the turbo. Then when I drive, I will get anywhere from about 12 to 15psi depending on the gear, in low RPMs. After about 4,800 RPMs, the boost falls off to about 2 or 3 by redline.

I've tested all the solenoids, and all are working fine. Here's what I don't understand. WHAT MAKES THE SOLENOIDS TURN "OFF" AND "ON"?

The problem I'm trying to solve is to make the control valve "shut" at idle. When I "hotwire" it, and bypass the solenoid, I have no problem making it shut at idle... because vacuum is present. So obviously, the charge control solenoid is not letting vacuum pass through the ports on to the valve. What has to happen in order for this solenoid to do this? It's not a broken solenoid... perhaps a certain signal that should be reaching the solenoid is in fact not.

Anything would be helpful. As soon as I solve for this, I will either A: Solve many other things, or B: At least be able to move on to why the boot doesn't work at the top end either.

So if I haven't gotten this straightened out by next month, I think I'll have a bonfire, complements of the 7.

Thanks.

dgeesaman

iTrader: (7)

The solenoids are turned off/on by the ECU.

If they aren't getting the signal at the right time, then:
1) the plugs are switched around
2) the wiring harness is bad
3) the ECU is bad.

KyleH

Can you explain what the parameters the ECU has to see before it know when to click the solenoids (in particular the charge control)? A certain RPM? There are in fact 3 vacum hoses on these solenoids, not just 2... so is there a vacuum input that triggers the solenoids, or is it all controlled by the ECU off of voltage readings somewhere?

Also, should the pressure chamber have pressure coming out of it all the time? Or only when the car is under boost?

wstrohm

KyleH,

Maybe I'm wrong, but it seems to me you have not checked out the possibility that you have the vacuum hoses crossed right at the rack solenoid valve. Earlier, you wrote this: "The rod stayed out all the time except when i shut the car off (it would go in and pop right back out when the ignition was shut off). " That is exactly what would happen if you had the hoses hooked so that the vacuum passed through only when the solenoid was inactivated but was blocked when the solenoid was activated. That is just the opposite of how it should work.

IMHO the PCME is doing exactly what it should but you need to switch the hoses at the solenoid valve. Please refer to the attached manual page in my reply above and check to see if this might be the case!

KyleH

Well you may be on to something. I have taken that manifold off at least 25 times in the past month, and rechecked all hoses. I know I have the solenoids hooked up right. But, you may be on to something... if it seems to be working backwards, why not just hook up the solenoid backward, so that the air flows the right way at the right time instead of the right way at the wrong time as it is now...

KyleH

For what it's worth, i tried it, no dice.

Sadness ensues...

KyleH

Well, I have the car apart right now... Just wondering if I can find some help on where a certain line goes. It's the aqua-blue/green line that runs from the turbo inlet up to the metal piping where it's then split off into 3 lines. 1 goes to turbo pre control, one to wastegate control, then there's a 3rd line that runs to a T and then hooks in two places somewhere...?? I see a nut at the termination of these lines. Previously I had this plugged off, but can someone tell me/show me what it is that this line plugs onto?

Here's the image, I apologize for the size.

KyleH

Okay, I found the nipples that those nuts represented. (Someone could really make something of that last statement.. )

Anyway, I tore the car apart... took the mani completely off, and verified all hoses... every single one. Had a partner with me, to check me. All hoses are now correctly hooked up. I have no boost leaks.

Here's the verdict.

This applies to all gears. If I go WOT below 4,500 rpm, as soon as I hit 4500 rpm, the car will come on with 7 or 8 psi of boost (remember, I have no pills nor a boost controller anymore, just a line connecting, so 7 psi should result from what I've read) that holds and then drops off to 4 - 5 psi by redline. Next gear, I get 0 - 1 psi of boost to redline.

This is the way it works for all gears. Not very exciting.

Also, STILL, I am not getting the charge control valve to shut at idle. PLEASE HELP!

Thanks
Kyle

KyleH

I did some testing. Here are the results from the solenoid(s) that should have an effect on the charge control valve. It would be really helpful if someone could at least tell me their thoughts on the following picture.



Obviously since no vacuum is passing through the charge control solenoid at idle, the charge control valve does not shut. What kills me is that when i shut off the engine, the valve then opens to allow vacuum to pass through and shuts the valve. Argh. Why?

dgeesaman

iTrader: (7)

I think on that diagram, they have F and H solenoids switched. Compare the way the vacuum lines are arranged vs. the regular diagram.

Just try switching the plugs on those solenoids - if I'm right, that alone should fix it.

Dave

martiny

I am struggling with a similar problem here in the UK, and I found this table very handy. It will anser your question as the what the ECU uses to decide when to switch the solenoid(s) on or off.


http://www.autosportracetech.com/RX-...erOverview.htm

KyleH

Thanks for the help fellas. I said screw it, and went with the parallel system.


It doesn't suck, but I'd have rather had sequential. Oh well, when I get a DP/high flow cat it will spool a lot quicker. At least now I have dependable boost... although as you read my other thread you see I've got new, but less problematic issues.