My car boosts properly for about the first 15 minutes before it's hot.

When hot the car produces (what feels like) no boost from secondary turbo. I still get some boost from primary, but if I go WOT, sometimes I get no boost at all.

I'm going to try installing a boost gauge this weekend to try and troubleshoot... anything else I should look at?

 

I see you are in NZ so you have access to more model years. What year car is it? Any modifications?

 

hey arghx, it's a 1993 R1. No mods on it apart form a slightly bigger catback exhaust than stock.

 

Has the ECU posted any codes? (Pull the codes even if there is no CEL) Where I'm going with this is to check to see if any of the solenoids go open circuit or short circuit when they get hot.

Unfortunately it's not the only possibility for your symptoms but it's not hard to check.

 

The CEL isn't coming on... I'll have a look if there are any codes being posted this weekend.

Hopefully the solenoids are posting a code, should be an easy fix then.

Thanks

 

I think a good question here is, why the hell are you even hitting boost before it's completely warmed up.

 

see if it posts [nonsequential]. . Just kidding

 

Sorry sir, I used the wrong words.

I always warm it up, idle about 5-10 minutes then drive about 5-10 minutes before boosting. More precisely would have been for me to say "it boosts properly before it's heat soaked".

 

It's definitely boosting sequential when it's not yet fully up to temperature. Pulls hard all the way through the RPM range in all the gears. I was amazed at how rapid the car is the first time I figured out that the second turbo was actually working properly.

I bought the car about 8 months ago without really testing it out properly or doing my homework. It was a really good price so I just jumped at it. It idled nicely and seemed to be boosting okay but I did think it was a bit slow at the time (I had never been in an RX-7 before).

 

Almost sounds as if there's a mixup with the vac lines and/or solenoid connectors between the double throttle control and the turbo control, which is possilbe since they reside next to each other at the front of the rack. The clue here is that the double throttle control only functions when the car is below operating temp (at least for 5 speed cars). You may be able to inspect this from the front by moving the pressure tank out of the way.

 

Thanks man, I'm dreading having to take off the UIM for this - anything that may help me diagnose the problem before having to pull that off is much appreciated. I'll be getting replacement rats nest vac hoses and gaskets ready before I really start digging in there. Thay way I can do everything at once and won't have to pull it off again any time soon (hopefully).

 

test your turbo pre-control and wastegate solenoid.

I had the same issue a few weeks ago... secondary turbo would only work when it wanted to, and when heatsoaked in the middle of the day, i get no love from secondary.

$120 later i got a new pre-control and wastegate solenoid from Ray @ Malloy and all has been good since

 

If that's the case then your FD has never been boosting properly. Any FD boosting properly will make virgins say GOD DAMN!!!!

 

I have the same issue with my car. Once heatsoaked I don't get fully boost. I'm not positive if it's the secondary turbo in my situation, as I only net about 5-7psi, instead of the 12-10-12 boost pattern I normally get.

So I'm interested to know what you find to be the issue. It's almost winter here so I'm going to start tearing into the FD as she will be parked in the garage anyways.

 

I'm also on the same boat as you bro, but i have a bucking problem. OP, please get back to us when you have a fix.

 

I just recently did a major vacuum hose job myself, and finally got everything right for the most part at least. It was the first time I had ever done anything like that before in my life so if I can do it, you can too. I'd recommend to rip everything apart and redo all of it. That's gonna be easier then trying to find 1 single problem when theres so many possibilities.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/im-ready-do-full-vacuum-hose-job-need-pointers-868621/

 

i have the exact same problem , already replaced all the hoses and no luck.


i'll try to replace the actuator 2morrow , and will let you know if it fixed the problem.

 

If you're getting a 10-8-10 cool and 7 psi or so after it gets hot you could have a problem with the restrictor pill hoses being old and expanding maybe?

Honestly with the age of these cars the best thing to do is just troubleshoot the whole system and verify each part functions, there are a number of writeups to help. Test all of the non-emissions solenoids, replace all the hoses (do NOT use cheap hose), replace the check valves with the viton ones, test your vac and pressure chambers for leaks, test your ypipe actuator and turbo actuators, verify your pill lines are good to go.

It's a lot less work just taking it apart and being methodical with it than chasing each little issue as it pops up.

 

update: just ordered the rats nest vac hose kit from hosetechniques.com, also got all new gaskets and check-valves from my Mazda dealer.

I will be following this to do the rats nest: http://rx7.voodoobox.net/howto/vachose/vacjob.html

I will be checking all my solenoids as per this: http://rx7.voodoobox.net/howto/solen...oid_check.html

 

Awesome, please keep us updated

 

remove the Y-pipe coupler and inspect it thoroughly.

i would guess this is 90% likely your issue, the coupler isn't as flexible when cold but when warm it is more flexible so any hairline cracks will blow by boost. the stock couplers are poor and only last about 100k miles(which isn't bad but guess how many miles most FDs have now? you guessed it).

 

I've got about 50k miles on mine, thanks tho I'll make sure to check it. Age probably pays a large part also, being a 93 car it's getting on in years

 

what do you inspect on the Y-pipe coupler? right now im having problems getting boost for my primary turbo but have full boost on my secondary.

 

Take it off and stretch it to look for cracks. It's such a problem that mazda changed to an all metal and gasket y-pipe in later models. you might want to pick one of those up, as it also replaces the plastic crossover pipe too. Less stuff to go bad is always good, plus plastic and rubber are 2 items that don't last long under that hood.

 

Problem is, boost leaks can be caused by more then vacuum hoses. It can be worn/damaged hoses, misrouted hoses, broken solenoid valves, sticking solenoid valves, using the inncorrect solenoid valves, broken/damaged actuators, leaking check valves, check valves installed the wrong way, or in the wrong place, and also intake leaks at the Y pipe. This is a massive job and I strongly recommend to replace and check EVERYTHING according to the FSM while down there, this is NOT something you wanna have to do again anytime soon. its a PITA