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-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   boost problem (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/boost-problem-278894/)

TurboII2NV 03-04-04 11:22 AM

boost problem
 
on a turbo ii 87
I hear the turbo works, blow off valve is ok and waste gate is ok
but when i get into the revs the car is not generating any power from the turbo ( only a little bit can be felt )

only once it did boost properly from 5000 to 6000rpm

there is no intake and exhaust

rxcollector 03-04-04 11:59 AM

how many miles are on the turbo?

MONKEYBONE 03-04-04 12:03 PM

Mine did the same thing. The engine was reving hard but it was building little boost. I did the TB mod and and removed the plates and then had serious boost issues. the plates were not opening up all the way.

TurboII2NV 03-04-04 01:33 PM

what is a TB????

HAILERS 03-04-04 02:11 PM

TB is either tuburculosis, Turbo Boy, or....throttle body. If its the throttle body then remove the intercooler. Look towards the front of the throttle body and at the front of the throttle body you'll see a rod with a spring over it and a small approx 5.5mm nut on the end. The nut will be facing you. Carefully remove the nut...then the spring, then the rod. Then get a ziptie and put it thru the hole where the rod was and tie it to the throttle body support frame (any part that does not move). That should hold your seconday outboard throttle plates to full open all the time Now go for a drive (don't forget to put the intercooler back on) and see if the boost is better.

Make sense??? Does to me anyway.

Rotory 03-05-04 10:27 AM

you can really wire your secondary plates open with no other adverse effects to the motor?

SureShot 03-05-04 10:43 AM

We are talking about the secondary double throttle.

It's job was to keep nimnulls from going wide open on a cold engine, and to slowly open after warmup.

The first secondary works directly, the double can stick shut.

Rotory 03-05-04 10:46 AM

you mean the plates that are supposed to be removed while doing the TB mod?

HAILERS 03-05-04 02:45 PM

**you mean the plates that are supposed to be removed while doing the TB mod?**

Yes. What I described is not the throttle body mod.....what it WILL DO, is keep the number TWO secondary throttle valve full open all the time. The number ONE will still be closed and controlled by your foot.

The number two throttle valve is purposly made to open slower than the number one secondary throttle valve. The is done with a black colored cam and a damper. After a number of years these parts can become worn....as in worn out. That causes the number two to hang up and sometimes not even open. When that happens you don't get the full throttle opening desired and you starve your engine of air. That's what the above post by MONKEYONE suggested.

I suggested this method because.......it does not cost a dime. It takes maybe twenty to thirty minutes to do and you know in forty minutes whether or not that was your problem. If you do the throttle body mod...... well...see you in a couple of days when you might have finished it.....and then that might not have been the problem to begin with and you would have wasted time for nought.

YOu NEED to down load the fsm from the internet for free.

Rotory 03-06-04 01:32 AM

i have an actual FSM sitting here in front of me it came with my car...i was making sure i was totally clear before i went and did this on my precious car and i know what that wiring theses open isnt the "TB mod"...jeez icemark. ive already done the tb mod on a spare TB i have but i just wanted to see if your idea would help my car before i tried swapping the modded TB over to it. thanks man!

HAILERS 03-06-04 07:47 AM

This jpg shows the linkage that I mentioned. It takes about fifteen to twenty minutes to remove and tie off. No throttle body removal required, only the intercooler.

If you remove this piece and tie off the linkage to full open it should give someone an idea if the throttle body mod is for them or not instead of doing the mod and then finding out it......was not worth the time.....and buggered up throttle body that no one in their right mind would pay full dollar for if they are buying your car.https://www.rx7club.com/forum/attach...postid=2749392

TurboII2NV 03-06-04 09:04 AM

thanks guys this helped a lot

TurboII2NV 03-06-04 09:06 AM

one more question
even when I open the throttle by hand and i see the secondary open as well shortly after, u say it could still be sticking internally?

HAILERS 03-06-04 09:17 AM

It's supposed to open a touch later due to the black cam riding on the dashpot (damper). It's possible that its hanging up sometimes. Removal of the above spring/linkage and tying it full open should resolve any doubt whether or not its that set of throttle plates that is causing your problem.

If you tie it open and the problem does not go away....then press on to some other thing as the cause and consider this having been eliminated as the cause.

If it isn't that....then maybe the precat is clogged??? Or the main cat??? Or???????

Rotory 03-06-04 11:08 AM

i gutted both my cats the other day ...it was no fun. it does sound better and seems to stay a TAD cooler but not much at all.

TurboII2NV 03-06-04 01:02 PM

oo ok but there is no exhaust on the car at all,

but I have checked the turbo, wastegate, and twin scroll, it is all working acording to specs,

but I do have some (little) bad idle as well, however there is no vacuum leaks that could be found nor is there an air leak

Rotory 03-06-04 05:33 PM

sure you arent hitting fuel cut with no exhaust ?

TurboII2NV 03-06-04 07:55 PM

I WANT TO THANK ALL THE GUYS THAT RESPONDED TO THIS POST.
IT HELPED MY A LOT AND THE CAR IS RUNNING LIKE NEW AGAIN. IT WAS THE SECONDARY ON THE THROTTLE BODY.

ONCE AGAIN THANKS ALOT.

AND ONE MORE QUESTION IS THERE SUCH A THING AS RX7 MEETS ONCE A YEAR OR SO WHERE EVERYONE MEETS UP

Rotory 03-07-04 02:11 PM

i just removed my secondary linkage...much easier than a TB mod and it helped out alot...thanks HAILERS

87RX7TII 03-08-04 07:59 AM

I have the same problem on my rebuild...
I think i'll try this little trick to see if it helps at all

Rotory 03-08-04 11:11 AM

yeah you should try it man...i didnt have any big problems, but doing this trick seemed to help the responsiveness of my car and might have even add a HP or 2

hondahater 03-08-04 11:52 AM

all this time I was having boost problems no one mentioned this to me. I am going to try this later. Thanks.

Rotory 03-08-04 11:55 AM

hey hondahater where in louisiana are you from...i was born in Slidell!

hondahater 03-08-04 11:57 AM

lol, I know where slidell is I'm in lake charles! Nice to meet a fellow louisianan! :)

Rotory 03-08-04 12:00 PM

yeah its always a pleasure...good luck with your car, it seems that i can maybe build boost a LITTLE quicker it might just be in my head and it seems to run smoother after taking off that linkage. It was very simple to take off even though i did lose the spring that was on the linkage:)


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