hey so i just picked up a twin turbo 93 imported rx7.

i am experiencing a BIG cut of some sort.

from idle to exactly 5000 rpm this thing runs beautifully. when it hits 5k it just cuts. completely shuts it down. as if the limiter is shutting it down.

now i thought at first it is experiencing some sort of fuel cut. i know that there is a limiter on this car but that should come in at redline, not 5k.

also im thinking it could have something to do with the ignition.

anybody else had this problem?

 

I'm having this problem right now. Try slowly accelerating, staying off of boost, and see if it will go past 5k. If it does, you probably have something wrong with your secondary injectors.

Here's my thread: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/right-diagnosis-818815/

 

It's your ignition. Check your spark plugs first ( renew ) and then upgrade your ignition.


later

 

But why would he upgrade his ignition? Stock ignition is fine for a stock setup.

Im thinking he has a failing coil or just needs spark plugs. The fact that it cuts off at 5k exact, all the time makes me think it has something to do with the injectors like someone said.

TO the OP: Can you rev past 5k in neutral?

 

If you have a PFC-

Another idea, if you try the other two ideas for revving past 5k and cannot do it, make sure the rev limiter in the PFC is not set to 5k. I know I adjust mine in the RARE case I have to take it to a shop to perform a service I cannot do in my garage (wheel alignment). I set it to 2k so no one may have fun at my cars expense.

Other than that it sounds like what is listed above. Secondary injectors come on line at just below that rpm along with the transition to the second turbo. Replace your spark plugs and wires, check components (vac lines, solenoids, ect. that deal with 2nd turbo), make sure you are getting voltage to your secondary injectors, have the coils checked... Those are good places to start.

 

nah it wont rev passed 5k even if i try to stay off the boost.


and i am not sure if i have a pfc i have only owned this thing for a week now. what is a PFC?

how do i set my rev limiter in the PFC?

i will change my spark plugs as well.

also i did take first gear passed 5k. i hope its not injectors.

 

A PFC is an Apexi Power Fc aftermarket ecu. The ecu is located behind the passenger kick panel. If it is a PFC, it'll say APEX'i on it. To check the rev limiter, you'd either need a commander or datalogit (not sure if the commander does it).
What do you mean you took 1st gear passed 5k? You said at the top of your post that it won't rev passed 5k.

 

Yeah I am a little confused too. He just said it wouldn't rev past 5k and then it will in 1st???

And yeah, you can adjust the rev limiter from the commander.

I think you need to provide much more detailed information on your problem so that we may give you more adequate/correct advice.

 

i had the same problem about a year ago, at first i thought it was fuel cut, then i tried all the ignition components, igniter, plugs, wires coils i tried it all, it was a combo of a bad engine ground and a fucken pinched vacuum line

check all your gorunds and make sure you dont have any vacuum lines broken, at least the ones that go to all the solenoids

 

what do you mean more info?

it wont rev passed 5k.

on light throttle in first it did.

what else can i say? that describes what the car is doing perfectly.

do the secondary injectors kick in at 4800 always? or only under a heavy load?

i checked my vacuum lines and i found that on the air box, above the filter there is a large line that comes out to the center of the engine bay. it curves downwards for about 8 inchs and then ends. to me that does not make sense, wouldnt it suck unfiltered air through that? it seems as if it should be plugged into something.

 

That is a contradictory statement and it does not make sense. Obviously we can deduct from it that in first gear possibly one time you were able to rev it past 5k... And attitude toward those that are trying to help you.....

Take a pic of the vac line you found laying unconnected and maybe we can identify it.

Try and pull any codes that the ecu is throwing (procedure is in the stickies).

 

Not sure if it makes any difference but you didnt answer my question before.

Can the car rev fine past 5k in NEUTRAL???

 

yeah it can in neutral.

 

The secondary injectors come on depending on load. That's why we've been asking whether or not you can rev past 5k in neutral and with light load.

I would guess the line coming out of the back of the air box is either for your BOV or your air pump. Either way, if it is on the top of the air box, it should be plugged. Do you still have the air pump? It would be a big thing with a pulley to the left of the alternator. If you post a pic, someone here can identify the hose too.

 

hm i wonder if the air pump not being hooked up would have anything to do with the power cut. and also the abysmal emissions tests results.

also today the second time the rx7 has been driven i really tried to find out exactly what the thing is doing.

in first gear it will rev right to the red line with no problems

second gear 5000 rpm cut
third gear 5000 rpm cut
fourth gear was at 4000 rpm,
and in fifth gear it would not go over 140 km

in third gear cruising at 2500 rpm, if i put my foot into it, the engine would cut.

i am going to have start removing the air box and look to see if that line came off the air pump.

i will post pictures tomorrow of the tube if i am unsuccessful.

 

HMMMMMMMMM........

Maybe this is too simple, but it sounds a lot like a clogged fuel filter. Either the "sock" filter before the pump, or the main filter that we all "love" to change. How long has your filter been in there since it's been changed?

 

YEAH!! i said fuel filter as well. i also said maybe the fuel pump, but weird that a pump would work and then suddenly not work so i kinda ruled that out.... for now.


and just to make things clear as to why this problem is not fixed yet, its not my car.

i have a 94 mazda mx3 that i swapped a 2.5l klze engine into

this is my friends rx7 that i am helping with.

do you have to drop the tank to get to the fuel pump? my friends supra had this exact problem and it was because the fuel tank was rotten inside (it sat forever) the sock was completely clogged.

i am going to have him bring the rx7 by my place today and im going to find out where this air pump is and see if that line should plug into it.

but so far guys, great help keep it up, looks like you have a good community here. props!!

 

Nope, there is an access plate in the rear on top of the tank that when removed accesses the pump and filter. It's under the carpet ahead of the spare tire well.

The pump can then be removed along with the tank cover plate, IIRC.

 

i have a problem with my 86 rx7 it would not rev above 2500 rpm and if you try to go above that it will die.

 

This question belongs in the 2nd generation (86-91) section, there are quite a few differences between the 2nd and 3rd generation cars that would make it difficult for most people in this section to answer your question. Check all the basics first, make sure all the sensors are connected, change the spark plugs and fuel filter if you can't remember the last time they were changed. If I remember correctly, the 86-91 models have an AFM (air flow meter) and will run like crap if there are any vacuum leaks.


Good luck.
-s-

 

Guys..check and change your fuel filters and pumps

 

Pop the connector off your secondary injectors-

Use a ohm meter and check for resistance of each injector

Bad injector-

Open circuit

It's a limp mode

Basically when ever it tries to use the secondaries it knows it doesn't work so just cuts off fuel to all injectors (why u can rev in neutral and it's gear dependant).

Had same problem - had a voltage spike and fried a injector (voltage regulator in my alt went out).

 

hey, ive got the exact same problem. where can i find the secondary injectors?

 

I have a parallel problem with my 90 vert na. It wont got over 4500-4800 rpm even in neutral. Checked all the grounds, new injectors, manifold gaskets, afm, checked and double checked for vac leaks. I just replaced the trailing coil and its sparking however I still have a trailing coil and bypass sol code. Somebody help me please!

 

Did you fix the problem mate? If so what was it in the end?