Primary spools up to 10psi nicely, drops down for a second, secondary comes online and just absolutely flys free to fuel cut. I'm going to take a look at the boost lines on the solenoids, actuators, all that nonsense...can someone tell me specifically where to start looking? Obviously if there's a hose popped off I'll put that back on and try it, but if there is something specific I should look for, can someone please help me out? I have a diagram of the car's boost lines, is there something else more helpful that I could possibly use?

Thanks in advance,

~Tim

 

Sounds like a wastegate issue. I'd start by checking the vac line from the nipple tree on the primary compressor to the wastegate actuator - most likely it's popped off. Dont just pop it back on, zip tie or clamp it down so it doesnt' come off again.

What are your mods? (if any)

 

Never mind, I found your mods in your other thread.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/new-fds-just-picked-up-my-car-477484/

If you've got those restrictor pills your missing, you could always try putting the wastegate one back in. Or just wait for your MBC to arrive to help you bring down the boost.

 

If you need help or another set of eyes, hit me up since I'm local...

 

wow these things are hard to get to...didn't have any of the right tools to take the airbox out, so I couldn't really see what was going on.

Jsplit, I'll PM you...

~Tim

 

i would have to agree with ur wastegate line popping off that hold the pill...air box has i believe 4 screws that hold it in

 

The plugs into the 2 solenoids, precontrol and wastegate, were swapped. Fixed that, boosts fine, except it still gets spikey in top gear on the highway...

Thanks a ton Jon, Shoot me a PM about that downpipe if your guy wants to sell it still.

~Tim

 

edit: According to the Vanditmars site it will create full primary and only 6psi at secondary. I think there is something else a little fishy here.

Dave

 

so do I....I'm not sure why it's still overboosting in top gear when I hit it on the highway (automatic tranny). The boost is perfectly stock in the lower 2 gears though, I'll have to maybe take a second look at everything to ensure that there's not something blatantly wrong happening.

 

Not sure about that site or that info, I've seen a few cars with runaway secondaries that have had a similar problem with the plugs swapped, but I wouldn't discount the fact that something else may be amiss. It just seem's odd that when we drove it last night through the first 3 gears it was just perfect and now is only spiking through the high gear...

Anyway, Tim I sent you a PM, give me a call when you can.

 

Maybe something in the WG actuator or the WG itself is getting hot and (sometimes) sticking it closed... That might explain happening in the higher gears, and the inconsistent symptoms.

 

Okay here's what's happening. When I switched the two plugs, it "fixed" the problem but didn't actually repair the incorrectly working parts. The first turbo spools up super fast to 10psi now, dips down when secondary starts prespooling, secondary comes online and it holds boost perfectly. The problem arises when I try to step on it in top gear, the car doesn't downshift it just rolls on, and the boost spikes on the primary. I think that the vacuum lines on that particular solenoid that is now "controlling" (or rather failing to control) the primary turbo are wrong, so that when the secondary is not engaged but the car is boosting hard because it's under high load on the first turbo, it's overboosting and fuel cutting. Basically, the secondary turbo's wastegate and exhaust housing are being used as the primary's only way to lower boost to target levels.....I'm convinced that the control to the primary's wastegate is in some way non-functional. The only reason the car drives fine around town from a stop now is that the secondary is giving a helping hand in boost control when it kicks on and preventing it from going way too high by opening it's exhaust housing and wastegate.

This confuses me, because it could be something mechanical with the turbo setup, it could be bad wiring between the ECU and the solenoids, it could be a bad solenoid, it could be a vacuum line popped off/cracked/broken/leaky/incorrectly hooked up. The problem is that from a very cursory look nothing seemed like it was wrong. Does anyone have any experience with this that would understand better what is happening and where to start the search for broken parts? Thanks,

~Tim