sr20det uses alot of gas...can it be the o2 sensor?

[Neil]

The idle WILL rise and fall while reorienting the cam angle sensor. That's perfectly normal. The idle adjustment screw should not have to be all the way in... When it tries to die and catch itself, it may be the ecu putting the fully shut iacv into 'panic' and having it open to get more air. Turn it out a few turns and then make sure the timing is fine. Make sure youre doing all this with the throttle position sensor UNPLUGGED. This is very important. Plug it back in and then go test 'er out.

The up/down idle sounds more like a throttle position issue. If you have a voltmeter its easy to see if the TPS is good. Shove an straightened paperclip down next to the middle wire in the TPS plug. (+)lead from the voltmeter goes to the paperclip. (-)goes to negative battery terminal. with ignition on, not running, throttle closed, it should read between .35 and .5 volts, and it should NOT fluctuate. It should gradually increase as you open the throttle body and go a little over 4 volts at full open. There are 2 screws you can loosen on the tps to adjust it if it's off. If the reading is fluctuating like it was with mine, it's probly got water in it. If its not fluctuating but you just cant get it set right, its gone bad.

I have the one I "fixed" off my motorset, it works 100% but the black casing is ground off on top so i could dry out the innards. You want i give good price. No boosheet!

[sr_powered]

ok, i have checked the tps, and all volts are to specs. back to my timing. i don't know what's the problem here, but when i fully retard the cas, the timing will go below 1000 rpm. (@ 750 rpm) remember, this is with the idle controller all the way down. what happens next made me think alot: when i advanced the cas to the proper timing, the idle will go up, now remember the idle controller in completely all the way down. when at proper setting, the idle sits roughly at about 1300 rpm. i don't get this part, and i am begining to wonder if my timing had jumped. but there are other concerns. my maf sensor. what is the voltage measurements for the maf sensor, and what wires do i check with. same think go for the o2 sensor too. thanks!

[Neil]

Setting the timing to 15° before top dead center is more important than idle speed... so dont retard the timing just to make the idle lower. 15° btdc ensures while driving that the motor will ignite the air/fuel mixture at the proper time and advance/retard to the right degree as necessary. Also remember SR's are supposed to idle at 1300rpm or so until they warm up. If it is warmed up tho try turning out the IACV some anyway, see what happens. it might get higher for a moment and then find its way back down.

unfortunately I don't know the right MAF and O2 voltage readings... From what was said earlier in this thread I think the redtop O2's will read up to half (.5) a volt. im not sure what a "good" reading would be. IIRC on my blacktop O2 there wire colors are white, black, and black/white. Im not sure which is which, but with key on if one of them is 12v, that's the O2 heater +. If one is 0.0 volts, that most likely the ground. If the other has a slight reading that's probably the one you need, but if you find that 2 of the 3 wires read 0.0 then you probably have a bad O2.

Try unplugging the O2 sensor from the harness, see if idle or drivability gets any better. If it does that's a hint.

For the MAF, I was told "as long as you can rev over 2500rpm, don't worry about the mass air flow sensor." My car seems to run ok without messing with the maf so I never looked deeper into that. you could try spritzing a blast of brakleen on the sensor itself tho. It didnt hurt any of my 3 s13's... just dont soak it

[sr_powered]

i don't know if this will affect the timing in any ways, but before i learned that the tps was supposed to be unplugged first, i had messed with the timing while the the engine was off and on WITH the tps still plugged in.

[Neil]

whatever effect that had wasn't permanent. just set it with the tps unplugged and go from there.

[johna_99_99]

did u ever try testing the tps itself........with the tps unplugged......take a multimeter am test the resistance on the bottom 2 prongs sticking out of the tps......u should get 0.7kohms with throttle released and about 5kohms at WOT. i had the same issue as you......then i tested my tps and it turned out to be bad.......i then unplugged it and went for a ride and everything cleared up.....now i just need to get it replaced

[Neil]

he tested output voltage of the center wire on the tps and said it was within specification. testing potentiometer resistance without current running through it may provide false readings, which is why the reccomended way is to test the middle wire for voltage with the key on.

[johna_99_99]

i was only going by the fsm instructions.....i would imagine those are correct

[sr_powered]

alrigtie...i think i might fixed my problem. i checked the o2, it was fine. i checked the tps, is was fine. i did my timing, still working on it. the only thing i didn't recheck upon was the BOV hose recirculating hose. i connected the hose and the engine runs strong and fine. no more gas stanking from my exhaust anymore, and no more hesitation anymore. so for all you sr-powered out there, if you are new to the sr20det, always connect the BOV recirculation hose to gain excellent performance out of your engine. by visiting this web site and reading for the posts, i learned more about my engine than i was before. thanks!!

[Neil]

Good to hear its coming around.

one thing tho.. The recirc hose can be left off, it would have the same effect as running an atmospheric bov. had you not capped off the fitting it goes to on the rubber intake tube? if so that explains a lot

[sr_powered]

yo neil, just some questions here. hows the timing marks on the crank pulley of the sr20det? is it "-5, 0, 5, 10, 15, 20" or "20, 15, 10, 5, 0, -5" ?? i got confused after reading some info on the the sr20 (se-r) i know they're the same motors, but some stuff can be different. so, which is it? and whats fsm?theyre using too much acroynms.

[Neil]

Theyre right the first time, -5, 0, 5, 10, 15, 20,

the 2nd from the far right IS 15 degrees before top dead center.

FSM = Factory Service Manual