sv51macross

iTrader: (1)

A couple q's I would like answered if anyone may help. (1990 N/A)

1: The smell of gasoline is pervalant, passengers have complained. Exhaust must be leaking under the car because the exhaust sounds like some noise coming from under car. Could it be a fuel leak, have been getting shi**y mileage, though I am a teen learning to drive stick . Think car is running somehting like 8:1.

2: Want to install A/F gauge to tell if my suspicion of the car running at 8:1 is correct. Can I directly connect the gauge to the O2 sensor, does it need calibration or interpretation unit?

3: Can any ol' shop tune the A/F ratio? No performance shops local, but Ann Arbor has some reputable repair places.

4: Engine may have oil sealing problems, I just don't know anymore (sometimes theres smoke, sometimes there is not, she may not have been warmed up). Car spent 2 nights in Michigan winter w/o antifreez, could that have damaged anything oil-related? (No white smoke) If side seals are failing, can engine be driven normally for a few months until cash can be saved for a new engine?

Aaron Cake

iTrader: (1)

A narrowband isn't going to give you an exact ratio, and won't read down to 8:1. I can't think of any wideband that would read that rich either. But it will tell you if you are too rich.

No, not unless you have some equipment that gives you control over the ECU. Such as full standalone or a piggy back fuel controller.

Straight water won't cause damage to the oil o-rings.

The test for worn oil o-rings is to hold the car at around 6K and wait about 30 seconds. If you start getting clouds of oil smoke then you have an oil issue. It's normal to puff out a bit of oil smoke at startup on a high mileage engine.

sv51macross

iTrader: (1)

Yeah, I did the "Acid test" on fc3spro.com's maintenance page (4k for 15 sec), but it was dark. Could'nt smell oil, just gas, leading one to believe that the car is running rich. Might have a missing O2 sensor, some ?'s under the car need to look at.
Anyway, this morning I was moving her out of the driveway so my mom could get her truck out, and when I parked in I revved the engine a bit, around 4k, the temp gauge was off the bottom rest, just above the "C" which I estimate means that the internals are warm, and there was some blue smoke. I tried it again, holding at 4 k for a few seconds, and i definitely smelled oil.
The engine has only around 70k, the only miles my dad and i put on it was him driving it from tecate mexico and me practicing driving for my road test. We have done a couple wot pulls shifting at redline, but not higher than 90mph, and both those times the engine was fully warmed and couldn't really see any smoke from any of my mirrors. Engine feels nice and strong, responsive, though it seems to vibrate at higher rpms, maybe just harder engine mounts and actually touching a part of the drivetrain? My only other references are my mom's 2002 F-150 and dad's 03' escape 2wd. Both slushboxes. The F-150 feels like a crude tanker.
Sorry for rambling abouth the problems. How do you define "clouds" of smoke, and would any problems in the emissions equipment have an effect on A/F? How many O2 sensors is the 90' NA supposed to have? Thganks for your help, really appreciate it.

Aaron Cake

iTrader: (1)

If the emissions stuff is not running correctly, the A/F ratio will be effected. Generally it will fail in such a way that it will appear rich on the gauge.

The RX-7 has only one O2 sensor. You'll find more details on the fuel system in the Haynes or FSM.

The Factory Service Manual can be found in the FAQ For FC thread. It contains all this information and more, and is an essential tool for any sort of service work that needs to be performed on these cars.

Additionally, the Haynes service manual for the 1986 thru 1991 RX-7 (both turbo and NA) can be found at most local auto parts stores or purchased from any good bookstore (ISBN number 1 56392 007 7). It is only about $25 and is a great quick reference for things like this. Not only does it contain most of the information in the FSM condensed into an easy to read format, but it includes full wiring diagrams as well.

These manuals will answer 99% of service related questions for the car and if you intend to do your own repair work, you will need at least one of them. Preferably both, since the FSM is a free download.

Sounds like your engine is fine as far as oil burning goes.

sv51macross

iTrader: (1)

Still would like a rough definition of "clouds" of smoke, maybe in aproxx cubic yard(s) 6 feet from or around vehicle?

Just did the "acid test" again, had someone hold her at 4k for15 secs, no smoke, except a puff of blue[smoke] from the left rear wheel well when the gas was let off. Also, an inconsistently timed popping sound about the same pitch as the exhaust at a rate of about 1-2 pops a second. Definitetely an exhaust leak under the car. What's the popping an dsmoke from? Repeated the test, no puff of smoke but the popping still there.