the krza

hey, i just got my 87 TII today, and aside from BS maitenance stuff i gotta do, i noticed 1 thing. the car had reached operating temp., and i wanted to see how it ran. so i decided to rev the engine, and as soon as i hit 4200rpm, the engine didnt go any further. it just kinda stood at 4200. now im somewhat new to rotaries, but this does not seem normal. also, the car was in neutral when this happened. any diagnosis will be appreciated!!

SaabGuy

Sounds like secondary injectors to me. You can read up on it under "Resources" "2nd Gen FAQ" on this web site. (www.rx7club.com)

I guess its a common problem, but not neccesarily a big problem.


I must also stress that these cars have the WORST soldering jobs. Pull all the electronics and resolder EVERYTHING.

the krza

so am i looking at a replacement, or maybe i should flow tested and cleaned?
what exactly is wrongwith them?

SureShot

Just go easy until you get the low rev limit bug fixed, in case it's leaning out. Now you can update your profile..

1FastT2

iTrader: (1)

Kinda sounds like clogged cats to me.

vaughnc

The krza,

Could be a few things. I'm not at home right now, so I can't reference the repair manual, but I'd assume:

Dirty Fuel Injectors
Clogged Fuel filter
Grounding to fuel injectors
Check voltage to the fuel pump
clogged fuel strainer (in the fuel tank)

the krza

thanx for the replies...now i have 2 questions.
1. WHY is there a limiter in place? is it the ECU telling me i cant go past 4200, or is it the engine telling me i cant?
and
2. what kind of injectors is everyone using? im thinking either RC engineering, or nippondenso?
thanx

vaughnc

Does the car rev to the readline in neutral? If not try manually pulling the idle thingy from the engine itself (in neutral of course). Does the engine lack power or shutter at higher revs?

Anything else that can help us troubleshoot?

I believe there have been similar posts on high rev problems. You should search both the 2nd gen section and 2nd gen archive.

Well besides a loose accelerator cable, mr hayes says:

anything that hampers the air/fuel burning which includes

- fuel delivery problems
clogged injectors
low fuel psi (pump or filters)
ecu or electrical fuel injector controls
6 port induction

- exhaust problems
clogged catalytic conveter

- spark problems
old plugs or wires
ingition system

- intake problems
dirty filter

- timing
etc.. etc..

Scott 89t2

yoru sendary injectors are probably not pluged in or need to be regrounded by the ECU. they come on at 3800rpm. so if they are not comming on. you wouln't be able to rev much past that while driving. however I would think you should still be able to rev it in N. you might just have a really bad 3800rpm stumble. what happens if you floor it and hold it while in N? still doesn't go past? or are you just reving quicking?

HAILERS

I'm just a negative person today. Its not the secondary injectors. Sitting in the driveway and reving the engine to 8000rpm will not get the injectors to come on line. There is no load sensed by the boost sensor(map) therefore no secondary injectors come on line. How do I know, you say? I have two meters connected to my prinary and secondary injectors and just did the above. The voltage drop on the primaries was from 12v to about 8v. The secondary voltage stayed at 12v. With that said, I have no bleeping idea why it does not rev higher. Check the fuel pressure and the fuel filters maybe, first. Does this sucker idle worth a darn? Oh! My old standby when I have no clue. Disconnect the tps plug and then start and rev the car. Better? As in much better? You got a rag in the inlet? I give up. Fuel or air problem one.(that means its definetly electrical).

the krza

what do u mean by tps plug?
sorry about all the annoying questions, but my first rotary experience isnt a good one.

let me give you a detailed description of everything:

the car is in Neutral at all times.
my foot is to the floor with the pedal, and it revs slowly to 4200rpm, then just stands there.
while this is happening, clouds of white smoke are comming out the back.
it could most definetly be a loose cable, i HOPE its just that.

also, thanks alot you guys for answering in such a nice manner...i used to have a 240sx, and the guys on freshalloy.com are dicks most of the time...but there was this one guy, asad, who is a genius.
anyway, thanx

Scott 89t2

?? I thought they came on at 3800 no mater what? I don't think you can measure the voltage can you? you'd need a tool to measure duty cycle or something.

but I do agree that it should rev even if they are not comming online since there is no load. maybe 2nd throttle butterflys are staying closed? I don't think it's a fuel problem. it would still rev with no load. I've had a fuel pump die on me before in another car. couldn't drive it over a couple grand but it would rev in N. maybe the timming is way off? don't know what to say about the smoke.

GothicBlade

Hey, youre from Freshalloy too? Cool. I'm G_Blade over there... I'm afraid I've defected to th FC for the time being though... I still want an S14 though... it will just have to wait a while

HAILERS

Yes you can measure or see when the injectors come on line or how much voltage drop there is as you depress the pedal. I have a meter taped into the ecu output of the primary and secondary injectors. If say your driving down the road at say 60 mph you'll see approx 11v on the primary output and 12 plus on the secondary output. Slam the throttle down in forth and you'll see the primary voltage rapidly drop down to under 3v. while the secondary is still approx12v. Then as the primary hits about the 3v, both primary voltage and secondary voltage will go to 8volts and both slowly decrease together. That as you said about 3800. I monitored bothoutputs sitting in the driveway and reved to 7000. The secondary sat at 12v and the primaries were around 10-11v. The pressure sensor/boost sensor plays a role as to when the secondaries come on line. But even with the wiring plugs off the secondary injectors the darn car should have reved to the red line. Gott go to work, Late.

the krza

so now im pretty much fucked...maybe i should take it to a mechanic, or even worse....the dealer..

HAILERS

Go to this site and section 4B in the manual and you'll look for the tps http://www.iluvmyrx7.com/Technical_I...ice_manual.htm Jimmy crickets! You forgot to tell us about the huge clouds of smoke! To me it sounds like you've got a broken apex seal on one rotor or worse. Tell you what. Pull the top two plugs out and the wires off the lower two plugs. On the drivers sideof the engine bay there is a row of fuses that are under a black rectangular cover. They are labled on the top. Pull the one that says ECU. Now put your finger over the forward plug hole and have somebody turn the engine over for about five seconds. Repeat this procedure for the rear plug hole. Did you notice that with your finger on one of the holes and the engine turning over , that there was hardly any or no pressure trying to push your finger off the hole. If the answer is that , Yes indeedy, on one of the holes there is no pressure shoving my finger off the hole. then the chances are prettty darn good that you need the engine rebuilt. So, does this car start right up and idle reasonable? Or is it one of those that cranks forever and then starts weakly? What did the previous owner say about the condition of the car?Try this site for TPS adjustment http://home.rmci.net/panther/tps.htm

TRUDSL

I recently bought this car for $1000 and I have a bit of a problem with it. Here is what my car does and when it does it and how bad:

What:
Looses power and will not rev, or will rev but very slowly anywhere from 2800-6000rpm. Car has been checked for codes but NONE come up with codescanner.
When:
Intensifies as the car gets hotter, never does it when it is just started. Car runs great when cold or 1-3 minutes after starting it.
Intensifes as the car gets lower on gas, when I have a full tank of gas, its not as bad but still very noticeable.
Intensifes with harder throttle, the harder I push the pedal, the lower the rpm it will bog out at.
How bad:
The car will jerk if I am driving, if I am parked, in neutral, it will just not go past a certain rpm, except when I push the pedal gently or hold it steady.

The car:
87 Mazda RX-7 NA, 114Kmiles, new NGK plugs, new wires, new coils, grounded to frame with a 4gauge wire, new BOSCH OEM type O2 sensor, previous owner told me work was done to replace the fuel pump, but thats all I know from before it. Engine has been cleaned thouroughly to notice any vacuum leaks. Recently tuned up, Fuel filter was not changed ($30 from Autozone even with my manager discount) but it looks very clean and appears to be previously changed. I will try the following very soon when I get a day off.
1. TPS and adjustment
2. Grounds to the injectors
3. Solder points on ECM
4. Fuel system pressure check (fuel pressure regulator)
5. Catalytic converter clog possibility

How do I know if my cat is clogged. Also, any person that may be able to help will be greatly appreciated. Thanks

HAILERS

Just a guess, but I'd go look at the fuel pressure. Both the output of the pump and the pressure in the fuel rail. The grounds on the ECU idea sounds good, but cheeez, they'd really have to be cruddy(high tech term for high resistance). All your ideas sound good, but I'd do the fuel thing above, and when you find the spare moment, take the fuel pump out (ten little screws) and examine the mesh filter on it. It could be clogged with a clear varnish that is not so easy to see unless you look for it. Do the main fuel filter also. See if Richard Head was there and put it in backwards. Yours sounds like a fun car. I don't think it will ever give you a dull moment. Will keep you out of trouble if your working on it all the time. (humor) Can't help on the catalytic converter stoppage.

Pacey3182

Hey HAILERS,


I've run into Richard Noggin from time to time. Think he did some work on my car, too.

HAILERS

PACEY......Yeah. Richard seems to really get around the country. His specialty is RX-7's. Left his mark on many of them.