So motor is installed, running, and car is driving. But one problem, after making a few accelloration, deaccelloration runs to seat the rings, it started to run really rough.
It has already been having major issues finding an idle, sometimes it does, sometimes it doesn't, but it got worse. After about 17 miles of driving, it is puffing BLACK smoke. When hooked up to a emissions machine it maxed out over 9.99% CO, so we are VERY rich here. Pulled out the spark plugs, brand new Autolite's, and they are pitch black. The O2 sensor I know needs to be replaced, also the EGR is completely removed. I am going to get a new O2 tomorrow and plug in the EGR and zip tie it out of the way.
I have secret cams, HO mani, lightened flywheel, 8.5:1 pistons, lightly ported/polished head, SS valves with 3 angle job, etc. but that is the major stuff. Any ideas will be appreciated, both for the idle and the richness, I think they are related though, when it is less rich with fuel, I think the idle will take care of itsself.
22 miles per gallon and dropping fast...
How's your map sensor???
When I had a really bad idle it was because of the map sensor - the car idled and generally ran like garbage - and VERY rich.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
map sensor is plugged into a vaccuum line on the HO throttle body, and mounted about 3 inches away from it. No OBD codes for the MAP yet, but it is plugged into vaccuum. Maybe I should unplug it and see what happens.
22 miles per gallon and dropping fast...
sounds like when my cams were off, holy crap my car had issues then, no power, black smoke, bad idle, terrible fuel milage.
If you unlpug your map sensor your car should rev up for a while, then when you plug it back in it will stumbble and almost die or die completely. (thats what mine did)
another thing, if you have an extra (1st) o2 sensor try putting a different one in, they hate the 'smell' of antifreeze. Some people frown on unplugging it and running the car, but IF and only IF, you are comfortable unplugging the o2 sensor, see if that makes a difference.
HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED
So it turns out it was a couple problems, first the O2 sensor was completely crapped out. Replaced that, CO dropped to about 5% on the emissions machine, and less missfire, idle also was a little more stable.
Then I plugged the MAP sensor into a nipple further back from the TB, and all my problems went away. Aparently there is slightly less vaccuum right at the TB, which caused the computer to think there is more air entering than there actually is. CO emissions are now at 0.00% to 0.01% at idle, perfect!
Now any ideas on why it idles at 1000 to 1050 RPM? I am thinking either a slight vaccuum leak or a bad IAC valve. Using the one off the HO mani. Damn this car is gonna be fast though, can't wait until the trip odometer dings 500 miles!
22 miles per gallon and dropping fast...
yeah i am pretty sure i had the same problems when i had my MAP sensor plugged into my throttle body. maybe i am wrong but the MAP should be plugged into a nipple on the intake manifold seeing its called a Manifold Absolute Pressure sensor? (MAP)
mario passarelli
speedfreakmjp wrote: maybe i am wrong but the MAP should be plugged into a nipple on the intake manifold seeing its called a Manifold Absolute Pressure sensor? (MAP)
22 miles per gallon and dropping fast...
LT1cavy wrote:speedfreakmjp wrote: maybe i am wrong but the MAP should be plugged into a nipple on the intake manifold seeing its called a Manifold Absolute Pressure sensor? (MAP)
Wikipedia wrote:The MAP sensor measures the "absolute pressure" (not manifold vacuum) in the engine's intake manifold. The mass of air entering the engine is directly proportional to its density. Density is directly proportional to the air's absolute pressure, and inversely proportional to the air's absolute temperature.
(Engine Mass Airflow Rate) ¡Ö (Air Density) ¡Á RPM
For a constant temperature
(Engine Mass Airflow Rate) ¡Ö MAP ¡Á RPM
Example: An engine that is operating at wide-open throttle on top of a very high mountain has a MAP of about 15" Hg (inches of mercury - approximately equal to the barometer). The same engine at sea level achieves 15" of MAP at approximately half-throttle. The engine requires the same mass of fuel in both instances because the same mass of air is entering the engine at both altitudes. In this comparison, the absolute air pressures are the same, the volume of the intake manifold is the same, and provided the temperature is the same - the densities are the same.
Obviously the engine will develop more output at sea level if the throttle is opened all the way because the MAP will rise to equal the sea level barometer's higher absolute pressure, increasing the density, which increases the mass, and consequently more fuel can be burned.
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