1986 S-10, 2.8 V-6, Automatic, Holley 400 CFM TBI, Edelbrock TES, MSD coil, Accel cap. rotor, wires, Bosch plugs, 3-wire o2 sensor, Maremont cat (a little over 2 yrs old). Failed due to Nox. High speed results were 2457 standard, 2915 current reading. Low speed was 2638 standard, 3552 current reading. Any ideas would be appreciated, as Cristmas is coming and I'm not too flush with cash. Thank you in advance, Mark. Sally sells sea shells by the sea shore because rough men stand ready to do violence on her behalf.
ideas>would be appreciated, as Cristmas is coming and I'm not too flush with cash.
EGR seems to check out as good. Pushed up on the valve and the engine bogs almost to death. Still looking for hints. Everything I installed is emissions compliant.
Sally sells sea shells by the sea shore because rough men stand ready to do violence on her behalf.
Do you think it could be no vacuum from the throttle body? Sally sells sea shells by the sea shore because rough men stand ready to do violence on her behalf.
Wow, a 2450 rating is *standard*? Mine with a 160k-mileage clogged cat, failed EGR and high-temp fuel-system cleaner running through the lines reached 2450, and that is nearly a gross polluter in NJ. Nothing over 1700 is allowed. What state is this? Texas?
Dan
PS To pass I replaced the cat & o2 sensor. NOx went from 2450 to 900, and HC & CO went to practically zero.
My Mazda Protege with 201K miles failed as well and it was just the timing...retarded it to the point it ran like a dog and it passed no problem. Then set it back up.
The vacuum should be running through a CTO valve. This only allows the vacuum to pass when the engine is hot. Maybe the CTO isn't working or the plumbing isn't right. I see messed up vacuum plumbing all the time.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Turns out that the previous owner had blocked off the EGR vacuum line. The only two vacuum lines I hadn't replaced were the two from the TBI to CTO and from CTO to EGR. Don't you just love happy endings? Thanks for all the hints and ideas.
Sally sells sea shells by the sea shore because rough men stand ready to do violence on her behalf.
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