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Odd sequential issue

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Old 11-02-21, 08:58 PM
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Odd sequential issue

So I am still at 8psi and semi slow spool on the primary..secondary kicks in and spools semi quick up to desired boost level, but not as quick as I think it should.
This evening a new issue. At one point the primary spooled a tad quicker, but still only 8 psi and the secondary comes on and everything drops to 4psi!!!! This should be kind of good news because it would point to the TURBO CONTROL ACTUATOR!!!???? Or am I getting to excited? What the hell else could cause lack of primary with semi normal secondary transition, but now starting to have an issue even on the secondary turbo.. Has to be a "door"/"gate" whatever you want to call it no?

This is where I am at so far.

New (3k miles) Hitachi 3kai with new wastegate and pre control actuators.

All solenoids under the UIM are new and tested.

I have checked all the hoses which are all new and routed properly from what I can see.

Y pipe coupler and IC piping is all new and from Turbo hoses and are the "hump" models with serious clamps

CRV tested. The slightest vacuum and it functions.

BOV was tested and works. I now have the "upgraded" bov from Pettit which works. I should probably install the old one back on until all this is resolved.

The charge control actuator moves with ignition and apparently works.

Check valves are all new. I believe they are all Dale's Vinton ones..

I need to jack the car back up and check the turbo actuator... I've been told this never fails.... so any other ideas?
I just remembered that I did not thoroughly check the vacuum chamber. I know there is a hose hooked up, but I never followed it.


Last edited by Testrun; 11-02-21 at 09:20 PM.
Old 11-03-21, 08:39 AM
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Are you able to pressurize the system and check for air leaks? I've never done it on a sequential car, only single turbo, but surely somebody here has done it?
Old 11-03-21, 08:45 AM
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Originally Posted by arghx
Are you able to pressurize the system and check for air leaks? I've never done it on a sequential car, only single turbo, but surely somebody here has done it?
Obviously I am not a mechanic, but I do not see why I couldn't do it some how. Not sure where ton start it.
I would like to know how to smoke something.
I know on the "boost side" the pressure tank holds pressure for a a couple weeks without any loss.
Old 11-03-21, 08:46 AM
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Do you have the pills in the line? 7psi typically means no pills.

Dale
Old 11-03-21, 09:05 AM
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Originally Posted by DaleClark
Do you have the pills in the line? 7psi typically means no pills.

Dale
Pills are in hardlines on the 3kai. This is a problem that developed recently.
I may put the manual controller back in as it is an easy swap..

When shifting or letting off it almost sounds like a compressor surge or something. Like a lot of pressure is built up and the turbo gets hit with it on decel. Make sense?

Old 11-03-21, 09:37 AM
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Since this is a recent development, it could be just a boost leak - have you re-checked the couples and clamps?
Old 11-03-21, 09:56 AM
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Originally Posted by Retserof
Since this is a recent development, it could be just a boost leak - have you re-checked the couples and clamps?
Yes... all of them.
Old 11-03-21, 11:34 AM
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Originally Posted by Testrun
Pills are in hardlines on the 3kai. This is a problem that developed recently.
I may put the manual controller back in as it is an easy swap..

When shifting or letting off it almost sounds like a compressor surge or something. Like a lot of pressure is built up and the turbo gets hit with it on decel. Make sense?
First off, do you know FOR SURE there are pills there? Also we don't know if the pill size changed or something with those turbos.

The "surge" could be something with the charge control valve not actuating.

You may need to do a pressurized boost leak test. Seal the intakes off, hook up compressed air at 15 psi or so, then look, listen, and feel for boost leaks. You want to be CERTAIN you don't have a leak before you crank the boost.

Also make sure precontrol/wastegagte control aren't swapped, that will do weird stuff. Either vacuum or electrical connector.

Dale
Old 11-03-21, 01:29 PM
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Originally Posted by DaleClark
First off, do you know FOR SURE there are pills there? Also we don't know if the pill size changed or something with those turbos.

The "surge" could be something with the charge control valve not actuating.

You may need to do a pressurized boost leak test. Seal the intakes off, hook up compressed air at 15 psi or so, then look, listen, and feel for boost leaks. You want to be CERTAIN you don't have a leak before you crank the boost.

Also make sure precontrol/wastegagte control aren't swapped, that will do weird stuff. Either vacuum or electrical connector.

Dale
I put a pill in the line just for the hell of it and 0 change. I then removed it and you can see inside the nipple and it is narrowed a bit like a pill.

I will jack the car up car prep to pressurize.

Hate to ask, but are there threads best describing this? Also tool to pressurize at 15 pso or stress-related? I have a vacuum pump and an air compressor.


You know maybe I should double check the lines on the apexi boost solenoid for the controller... , but I am pretty sure all was great, but I will check it.

Last edited by Testrun; 11-03-21 at 01:35 PM.
Old 11-03-21, 02:51 PM
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So.....do you have a boost controller or are you using stock boost control? Big difference there.

You can watch videos/read write-ups on doing a boost test. My method -

- Get an air blow-off thing to connect to the air hose on your air compressor, preferably one that has a long tip that you can put in a vacuum hose and make a tight seal.
- Crank the regulator down on the air compressor to 15 or 20 psi.
- Remove the air filters.
- Cap the spot where the air filters went. You have to be creative here. I've used thick plastic (like a plastic bag that a part came in) doubled/tripled over then hose clamped over the spot where the filter went. Just have to seal it air tight.
- Find a vacuum line that you can use to hook the air compressor to. I think it helps to do one that's before the throttle body.
- Pressurize the intake. It will not all stay in there, it will leak out which is normal so you have to keep giving it pressure. Look, listen, and feel for leaks. You can typically feel an air leak VERY easily. Run your hands all over every portion of the path the air takes - Y-pipe, blow off valves, intercooler couplers, throttle body elbow, etc. Go slow and take your time.

It doesn't take much to have enough of a boost leak to have a problem.

I THINK the charge relief valve is under vacuum even with the car off so you may have a leak from it, may have to unplug the vacuum line then re-connect to relieve the vacuum in the vacuum tank.

All else fails drive up to Pensacola and we'll knock it out

Dale
Old 11-03-21, 03:09 PM
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Originally Posted by DaleClark
So.....do you have a boost controller or are you using stock boost control? Big difference there.

You can watch videos/read write-ups on doing a boost test. My method -

- Get an air blow-off thing to connect to the air hose on your air compressor, preferably one that has a long tip that you can put in a vacuum hose and make a tight seal.
- Crank the regulator down on the air compressor to 15 or 20 psi.
- Remove the air filters.
- Cap the spot where the air filters went. You have to be creative here. I've used thick plastic (like a plastic bag that a part came in) doubled/tripled over then hose clamped over the spot where the filter went. Just have to seal it air tight.
- Find a vacuum line that you can use to hook the air compressor to. I think it helps to do one that's before the throttle body.
- Pressurize the intake. It will not all stay in there, it will leak out which is normal so you have to keep giving it pressure. Look, listen, and feel for leaks. You can typically feel an air leak VERY easily. Run your hands all over every portion of the path the air takes - Y-pipe, blow off valves, intercooler couplers, throttle body elbow, etc. Go slow and take your time.

It doesn't take much to have enough of a boost leak to have a problem.

I THINK the charge relief valve is under vacuum even with the car off so you may have a leak from it, may have to unplug the vacuum line then re-connect to relieve the vacuum in the vacuum tank.

All else fails drive up to Pensacola and we'll knock it out

Dale
Dale becareful as I may end up your way lol.

I am running off the PFC with the apexi boost solenoid.

I don't think my little compressor had a regulator, but I am sure I can add one.

When you say hook up to a vacuum line I am uner the impression I am hooking up to a line that will be positively charged and I should keep the intake pipes capped as good as I can..obviously airtight if possible.

I will do some searching to see which line would be best.

Old 11-03-21, 03:46 PM
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Hey...Cut it out!

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This may sound dumb, but when's the last time you tested your Wastegate and Turbo Pre-Control solenoids on the front side of the UIM? It sounds suspiciously like either the wastegate or both solenoids are leaking just enough to throw a monkey wrench into the works. Since both actuators operate by pulling open when vacuum is applied, a small leak in their respective solenoids would open them prematurely, hence low and lower boost respectively.
Old 11-03-21, 03:55 PM
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I actually just replaced all the solenoids under and in front of the UIM. I wish I could say otherwise. I appreciate the approach!!
Old 11-03-21, 04:56 PM
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Hey...Cut it out!

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Originally Posted by Testrun
I actually just replaced all the solenoids under and in front of the UIM. I wish I could say otherwise. I appreciate the approach!!
Not to sound like a broken record, but new =/= known good. If you have a Vacuum Pump (Mityvac), I would test all of the plumbing for both Wastegate and Pre-Control Actuators at the Front Turbo Inlet, independent of everything else. I'd bet money one or both isn't holding vacuum, probably when hot. Vacuum leaks seem to appear more consistently on a hot engine vs a cold one. Follow the test protocols here and the problem child WILL be unmasked:
https://www.rx7club.com/3rd-generati...-stuff-802060/
Old 11-03-21, 05:27 PM
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Originally Posted by Akagis_white_comet
Not to sound like a broken record, but new =/= known good. If you have a Vacuum Pump (Mityvac), I would test all of the plumbing for both Wastegate and Pre-Control Actuators at the Front Turbo Inlet, independent of everything else. I'd bet money one or both isn't holding vacuum, probably when hot. Vacuum leaks seem to appear more consistently on a hot engine vs a cold one. Follow the test protocols here and the problem child WILL be unmasked:
https://www.rx7club.com/3rd-generati...-stuff-802060/

Skip on away with that record. I can check it. Or swap back to my old one that I know was working... or both. It is cold or hot. No difference.
Old 11-06-21, 06:50 AM
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Work has me moving a lot right now (which is a good thing) so this might take me awhile to get around to. Is there a reason why I can't pressurize one of the 1" hoses. The crv or the bov hose itself?
just trying to get a plan and think of the easiest way.. the intake sounds difficult as it is so damn wide.
Old 11-09-21, 08:22 PM
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Originally Posted by Testrun
I actually just replaced all the solenoids under and in front of the UIM. I wish I could say otherwise. I appreciate the approach!!

Ok, I feel like a dumbass, but I am happy.
I had the damn pre control plugged into the wastegate solenoid. I don't know how the hell I didn't notice it before and how the hell I did that, but I did.
It is boosting very quick on the primary and transitions normal I had the manual boost controller back in and not sure what the setting is so I didn't want to keep my foot down. I will hook the apexi solenoid back up and give it a go.

I consider this closed. I will post if something else was wrong.
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