I have a '90 GXL N/A, all stock, and it is just pouring fuel out the exhaust. My dad couldn't even follow my car because his eyes would water from the burning sensation. I am also getting 10 mpg, which really SUCKS, in more then one way, too . I am really starting to get fed up with this, to the point that when it comes down to it, if I get the money, I may just get a SAFC of some type to handle this.

I just got a used TPS from a forum member a couple months ago because of this problem. That cleared up the problem a little bit, I started getting 12-15mpg for a time, but it is back down. I don't run premix, still use the OMP, and I just got new spark plugs, which I think are fouled already because of this problem.

I don't have any hot start problems, which I think rules out leaky injector(s). This is about the only problem I have with this car right now, excluding suspension problems (thats another sob story in itself).

 

I'd say have your injectors cleaned. Bad atomization will drop mpg's too. Check your fuel system for leaks. Are you running stock injectors?(I know you said all stock but are you sure?)

 

positive they are stock 460cc HI injectors, never cleaned either. Probably time to go to cruzin' performance, eh?

 

yea cruzin performance is the place

 

Burning of eyes...welcome to the wonderful world of the rotary!

 

My 91 N/A was running rich...it's a white car and I had ugly black deposits on the bumper over the tail pipes. I replaced the O2 sensor and the problem went away

 

forgot to mention, new bosch O2 sensor when I bought the car in feb, so I doubt it is bad, but it is possible, I guess. I know that rotary's run fat, but this is friggin rediculous, I mean 10mpg city without (much) hard running don't sound right to me, compared to most other N/A owners on this forum.

 

You need to "whip out" the FSM and take a couple of days reading your different sensor inputs at the ECU while driving, the ones that have to do with fuel scheduling. TPS, AFM, air temp & water temp sensors, you get the idea...

 

how exactly are you suppose to get these readings well driving?

 

shift at 2500RPM it will help you save some gas

 

By having the meter lead "back-probed" into whichever pin you're reading, of course (simple voltage-to-ground type measurements). I check out all the inputs over the course of about a week every 6 months or so, just to make sure everything's as it should be. Really easy to do (unless you have passengers all the time), and it's comparable to a "functional check" of all the car's important systems, done at one spot...

 

oh i see....then just watch what kind of voltage you are getting. that was a stupid question of me :P

 

m'kay... But still, the question I have up for grabs, is 10 mpg a little low for my RX-7?

 

I'd say so... I'm getting 14-15mpg in my 90GXL with an o2 sensor that really needs replaced... (got the part, its just a PITA to get a wrench to)

 

You can put a test lite on the ECU and see if the O2 sensor is going into closed loop mode. Look around and you'll find out how to build a code reader for the ECU.

Scott

p.s. Oh yea, check your fuel pressure and make sure it is around 28.5 psi. If the FPR sensor line is off or leaking you'll get about 38 psi--that will surely make you run rich.

 

Yeah, I will look in to the test light setup, as for the FPR, I assume that you mean Fuel pressure regulator line (hopefully I am not as much of an idiot I think I am at times) I will have to look at that tomorrow. Also, to check the fuel pressure, I have to make a fitting to go in the line after depressurizing the system, correct?

Thanks for the help all,

Dan

 

Well, went through and checked sensors and fuel connections, as well as fuel pressure. all were within spec as specified by the FSM, so the next part of this perilous journey is to pull the injectors and have them cleaned Don't know what I will drive in the mean time though...

 

For now, just swap the secondary injectors into the primary positions. They have much less "mileage" on them compared to the primaries, and if clogging/bad spray patterns is in fact your issue, this might help. This is assuming they are the same size injectors, of course...