Tech / General EngineWhy is my car making that sound? My car won't start! Combination questions? Don't see a board for your problem or have other technical or engine specific questions? Post them here!
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I took my car to get it inspected today, and failed smog miserably. High speed nox was 6811/1014, low speed was 7832/1110. My cat, O2 sensor, and EGR are barely a year old, no check engine light. However, the car did have some 4 month old gas in it, as it's been sitting a while. I put fresh gas in with the old gas, but could that be part of it? I'm gonna go do some datalogging in a bit, and see if anything looks odd. Any suggestions?
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__________________ North Texas Third Gen Association 1988 GTA 5.0/M5/3.45 LSD, T-Tops, Digital Dash, Leather - Current Ride 1983 Firebird S/E - Stripped 1995 Chevy 1500 5.7 Ext. Cab - Daily Driver
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WOW! i have never seen NOx that high before.
around 3500 is the highest i've seen, and that was with the timing set too high, no EGR, no cat, and running lean because of a bad fuel pump.
bad gas can cause excessive emissions, so run all the old gas out of it with some super then make sure the timing is right and the EGR is working.
also check it for vacuum leaks, fuel pressure and overheating.
Here's the full printout. The HC was a little high, but that's probably due to my ford 19# injectors. I can fix that with a tune. Also, the gas cap failed, but that's easily replaceable.
prolly for a start-tee in a vac gauge to the egr valve line that you can run to the windshield and watch as you drive around to verify if you are getting any vacuum (pwm) to the egr valve. i agree-wow for the nox number. if vacuum is being applied-check your egr valve at idle with manual vacuum-it should make the motor stumble. check timing. retard as required. you may need a cat.
__________________ 1985 IROC Original Owner.Original silver paint, Roller 406c.i., 4 bolt, Superram, accel DFI 6. serpentine setup, Factory GM 1LE brake set-up, richmond 5 speed, 1 3/4 slp, jet hot, gale banks 2OTL power pack (vintage), eibach, grey leather flo-fits, A/C delete, 29k original miles and never been driven in the rain. all original parts are on the shelf. original window sticker and build sheets. 1996 Z28 M6 LT4 kit, hotcam, obd1, C5 brakes. And then theres the road runner.
prolly for a start-tee in a vac gauge to the egr valve line that you can run to the windshield and watch as you drive around to verify if you are getting any vacuum (pwm) to the egr valve. i agree-wow for the nox number. if vacuum is being applied-check your egr valve at idle with manual vacuum-it should make the motor stumble. check timing. retard as required. you may need a cat.
My problems seem to have started after I put a TPI fuel pump in my TBI 305. MY EGR is also stock with 120k on it. I might try to check the passage ways and run some high octance
1985 IROC Original Owner.Original silver paint, Roller 406c.i., 4 bolt, Superram, accel DFI 6. serpentine setup, Factory GM 1LE brake set-up, richmond 5 speed, 1 3/4 slp, jet hot, gale banks 2OTL power pack (vintage), eibach, grey leather flo-fits, A/C delete, 29k original miles and never been driven in the rain. all original parts are on the shelf. original window sticker and build sheets. 1996 Z28 M6 LT4 kit, hotcam, obd1, C5 brakes. And then theres the road runner. 
