B16 No cold/fast idle, rich mixture code p0172.
02-07-2010, 09:02 AM
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B16 No cold/fast idle, rich mixture code p0172.
2000 EK, 99 B16a2, obd2 p2t ecu. The engine was recently rebuilt to freshen it up, nothing wrong, just new seals, gaskets, honed, decked, valve job, cleaned/measured etc....
Since reinstalling the engine I can't get it to take up it's cold/fast idle when it's freezing outside.
Initially it wouldn't start right up after the rebuild, had to pull the idle up a little to keep it running so I took the iacv off and cleaned it up and it ran fine, actually had to back off the idle screw quite a bit to bring it back down to 800 rpm (this was summer, nice and warm outside).
now that it's winter the car will not start and pick up fast idle by itself, I have to hold the gas and regulate the idle until it's warm enough to stay at approx 1500 rpm by itself - 30 secs to 1 min, then it's fine.
there is a rich fuel trim code which I guess is bogging the engine when it's cold, you can tell it's choking.
it's an obd2 engine so there's no Fitv.
I've tested for vacuum leaks, map values, tps values, changed both O2's, evap purge holds vac, compression strong and even, repalced the stat and flushed the coolant, checked fuel pressure (normal) checked fuel return and feed hoses and regulator (normal) and have checked and adjusted the valves twice, cap,rotor,plugs and wires replaced last summer.
there were no fast idle problems or rich codes before the rebuild, the injectors in the car now are the same ones as before the rebuild, same ecu, same harness.
I did notice that if I start the car, get it to idle, and let it warm up completely before driving it, the ecu will not throw rich codes, but if I drive it before it's fully warm and do any amount of idling, even stoping at a stop sign, it will usually set the rich code.
Once the car is warmed up it works perfect, with the exception of fuel trim value being about 0.8 when it should be about 1.0.
I'm sure there are other checks that I've done but can't think of right now,
any thoughts? help would be appreciated.
has been going on now since June and I'M OUT OF IDEAS, please help...
Since reinstalling the engine I can't get it to take up it's cold/fast idle when it's freezing outside.
Initially it wouldn't start right up after the rebuild, had to pull the idle up a little to keep it running so I took the iacv off and cleaned it up and it ran fine, actually had to back off the idle screw quite a bit to bring it back down to 800 rpm (this was summer, nice and warm outside).
now that it's winter the car will not start and pick up fast idle by itself, I have to hold the gas and regulate the idle until it's warm enough to stay at approx 1500 rpm by itself - 30 secs to 1 min, then it's fine.
there is a rich fuel trim code which I guess is bogging the engine when it's cold, you can tell it's choking.
it's an obd2 engine so there's no Fitv.
I've tested for vacuum leaks, map values, tps values, changed both O2's, evap purge holds vac, compression strong and even, repalced the stat and flushed the coolant, checked fuel pressure (normal) checked fuel return and feed hoses and regulator (normal) and have checked and adjusted the valves twice, cap,rotor,plugs and wires replaced last summer.
there were no fast idle problems or rich codes before the rebuild, the injectors in the car now are the same ones as before the rebuild, same ecu, same harness.
I did notice that if I start the car, get it to idle, and let it warm up completely before driving it, the ecu will not throw rich codes, but if I drive it before it's fully warm and do any amount of idling, even stoping at a stop sign, it will usually set the rich code.
Once the car is warmed up it works perfect, with the exception of fuel trim value being about 0.8 when it should be about 1.0.
I'm sure there are other checks that I've done but can't think of right now,
any thoughts? help would be appreciated.
has been going on now since June and I'M OUT OF IDEAS, please help...
12-18-2010, 04:46 PM
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Re: B16 No cold/fast idle, rich mixture code p0172.
having similar probs on my 93 ls, but i do have a fits and i did mess with it in attemps to fix a fluctuating idle that ended up being something else any pointers. is there a way to **** up the fits just by taking it off and putting it back on obviously i think i did it right but any suggestions?
12-18-2010, 06:12 PM
#3
Honda-Tech Member
Re: B16 No cold/fast idle, rich mixture code p0172.
2000 EK, 99 B16a2, obd2 p2t ecu. The engine was recently rebuilt to freshen it up, nothing wrong, just new seals, gaskets, honed, decked, valve job, cleaned/measured etc....
Since reinstalling the engine I can't get it to take up it's cold/fast idle when it's freezing outside.
Initially it wouldn't start right up after the rebuild, had to pull the idle up a little to keep it running so I took the iacv off and cleaned it up and it ran fine, actually had to back off the idle screw quite a bit to bring it back down to 800 rpm (this was summer, nice and warm outside).
now that it's winter the car will not start and pick up fast idle by itself, I have to hold the gas and regulate the idle until it's warm enough to stay at approx 1500 rpm by itself - 30 secs to 1 min, then it's fine.
there is a rich fuel trim code which I guess is bogging the engine when it's cold, you can tell it's choking.
it's an obd2 engine so there's no Fitv.
I've tested for vacuum leaks, map values, tps values, changed both O2's, evap purge holds vac, compression strong and even, repalced the stat and flushed the coolant, checked fuel pressure (normal) checked fuel return and feed hoses and regulator (normal) and have checked and adjusted the valves twice, cap,rotor,plugs and wires replaced last summer.
there were no fast idle problems or rich codes before the rebuild, the injectors in the car now are the same ones as before the rebuild, same ecu, same harness.
I did notice that if I start the car, get it to idle, and let it warm up completely before driving it, the ecu will not throw rich codes, but if I drive it before it's fully warm and do any amount of idling, even stoping at a stop sign, it will usually set the rich code.
Once the car is warmed up it works perfect, with the exception of fuel trim value being about 0.8 when it should be about 1.0.
I'm sure there are other checks that I've done but can't think of right now,
any thoughts? help would be appreciated.
has been going on now since June and I'M OUT OF IDEAS, please help...
Since reinstalling the engine I can't get it to take up it's cold/fast idle when it's freezing outside.
Initially it wouldn't start right up after the rebuild, had to pull the idle up a little to keep it running so I took the iacv off and cleaned it up and it ran fine, actually had to back off the idle screw quite a bit to bring it back down to 800 rpm (this was summer, nice and warm outside).
now that it's winter the car will not start and pick up fast idle by itself, I have to hold the gas and regulate the idle until it's warm enough to stay at approx 1500 rpm by itself - 30 secs to 1 min, then it's fine.
there is a rich fuel trim code which I guess is bogging the engine when it's cold, you can tell it's choking.
it's an obd2 engine so there's no Fitv.
I've tested for vacuum leaks, map values, tps values, changed both O2's, evap purge holds vac, compression strong and even, repalced the stat and flushed the coolant, checked fuel pressure (normal) checked fuel return and feed hoses and regulator (normal) and have checked and adjusted the valves twice, cap,rotor,plugs and wires replaced last summer.
there were no fast idle problems or rich codes before the rebuild, the injectors in the car now are the same ones as before the rebuild, same ecu, same harness.
I did notice that if I start the car, get it to idle, and let it warm up completely before driving it, the ecu will not throw rich codes, but if I drive it before it's fully warm and do any amount of idling, even stoping at a stop sign, it will usually set the rich code.
Once the car is warmed up it works perfect, with the exception of fuel trim value being about 0.8 when it should be about 1.0.
I'm sure there are other checks that I've done but can't think of right now,
any thoughts? help would be appreciated.
has been going on now since June and I'M OUT OF IDEAS, please help...
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