i have an 1998 2200.someone told me today that my map sensor might be bad.then someone else said my car doesn't have one.can someone tell me who was right.and where to locate it there is one.
Well, I cant tell you if the first person was right or not, because you haven't said if your car is running strange or wrong. Next, the second person is very wrong.
The map sensor is located in the intake right next to the throttle body on the passenger side.
Its the little blue and white tagged sensor right under the throttle body in this pic:
'99 2200 LS CX1 Sport
whoever told you your car doesn't have a map sensor is an idiot and you should never listen to him again because his credibility for anything has just been revoked. by me.
I was a retard, and now I'm permanently banned.
maybe stupid, but but at least i know that there IS one...what specifically does it do???
I was thinking along the lines that it split up the gas, and air mixture between the cylinders!! if its right at the throttle body, then obviosly i'm wrong.
I 'm in dire need of a good learnin..... you know that Flriduh ejumakasion!!!
wait for it... wait for it... NOW GO!! ---> '02 LS Sport <---
Yahoo IM : buzz122 AIM : buzz122cav
buzz122 wrote:maybe stupid, but but at least i know that there IS one...what specifically does it do???
I was thinking along the lines that it split up the gas, and air mixture between the cylinders!! if its right at the throttle body, then obviosly i'm wrong.
I 'm in dire need of a good learnin..... you know that Flriduh ejumakasion!!!
The internet is so resourceful...read this:
fastfieros.com wrote:MAP Sensors and how they work
The MAP sensor is an important part of the modern engine control system. When asked, “What does MAP mean?” most technicians could correctly answer, “Manifold Absolute Pressure.”
The next question, though, would stump most.
What is absolute pressure?
In absolute measurement, the zero point (where the measuring device indicates zero) is an absolute zero pressure. That means no pressure, or in other words, a 100% vacuum.
The pressure gauges I have indicate zero when no pressure is being measured. Isn't this absolute zero?
No. Most pressure or vacuum gauges indicate zero pressure when not connected, or when there is no pressure or vacuum being measured. However, there actually is pressure -- the atmospheric pressure that surrounds the earth.
You mean barometric pressure?
Yes, even though your pressure or vacuum gauge may indicate zero, the atmospheric or barometric pressure is always present. Conventional gauges always measure gauge pressure.
What is gauge pressure?
Gauge pressure has its zero point at the current barometric pressure (fig. 17). Everything above barometric pressure is called pressure and everything below barometric pressure is called vacuum.
A - Gauge Pressure Zero indicated here
B - Absolute Pressure Zero indicated here
C - Current barometric pressure
D - Atmospheric Pressure
E - Vacuum
F - Perfect Vacuum
G - Operating Range of Standard Pressure Gauge
H - Operating Range of Standard Vacuum Gauge
Conventional pressure or vacuum gauges are constructed to measure gauge pressure to keep the cost affordable.
An absolute pressure gauge is bulky and expensive. Laboratory-grade devices that measure absolute pressure cost over $1000.
Tell me about atmospheric, or barometric, pressure.
The two terms are interchangeable. Atmospheric pressure at sea level on a standard day is approximately 14.7 pounds per square inch (psi), or 29.9 inches of mercury (HG), or 101 kilopascals (kPa), or 1 Bar.
These various standards differ only in the units of measure used to express them.
Does atmospheric pressure always stay the same?
No. Two factors can make the atmospheric pressure vary. First, at an altitude above sea level the atmospheric pressure goes down, because the density of the air goes down.
Second, weather or climate can change the atmospheric pressure -- high pressure or low pressure days. This is why the standard sea level atmospheric pressure is listed as being on a standard day.
How do my conventional pressure or vacuum gauges act at various altitudes?
They react the same at high altitude as at sea level, which is exactly the point we are getting to.
Conventional pressure gauges have no way to compensate for different altitudes or weather changes. They will indicate zero either at sea level or at the top of a mountain. However, the atmospheric pressure is certainly different at these two extremes.
Why is this atmospheric pressure measurement so important?
The air in the atmosphere contains oxygen. An engine burns a mixture of oxygen and fuel. For an engine to burn efficiently, it has to have just the right mixture of fuel and oxygen.
To determine the correct air/fuel mixture and the correct ignition timing, the PCM must know the atmospheric (BARO) pressure. If the PCM is to compensate for changes in altitude or weather, it must have an input signal that reflects these changes in atmospheric pressure.
The Manifold Absolute Pressure sensor does this?
Yes. And, on engines that do not have a Mass Air Flow (MAF) sensor, the MAP sensor signal is also used by the PCM to calculate engine load -- how hard the engine is working. This is called the speed-density method of calculating engine load for engines without MAF sensors. It is because of this engine load calculation for speed-density engines that the accuracy of the MAP sensor signal is so critical.
On OBD-II engines, the MAP sensor signal is also used for EGR diagnosis.
What are the normal ranges of the sensor's output voltage?
The most common MAP sensor generates an output voltage between 0 and 5 volts, depending on the pressure being measured. It must be able to measure atmospheric pressure at the lowest elevations, which in some areas is slightly below sea level. The standard atmospheric pressure at sea level is about 101 kPa. In the Death Valley, Utah, which is below sea level, the atmospheric pressure can be higher than 101 kPa. At the top of Pikes Peak mountain in Colorado, which is more than 14,000 (4,267 m) feet above sea level, the baro pressure is less than 65 kPa. So, the MAP sensor must have a measurement range of 105 kPa to about 15 kPa.
How does the MAP sensor measure pressure UP from absolute zero?
Imagine two glass jars glued together at the open ends, with a flexible membrane sealed between them. Drill a hole into the bottom of each jar, and glue a tube into each hole. Now, connect a powerful vacuum pump to one of the tubes.
When the vacuum pump removes ALL the atmospheric pressure from the jar, seal the tube, trapping the vacuum in the jar. The flexible membrane will be pushed in towards the vacuum chamber jar by the atmospheric pressure in the open jar.
The vacuum jar has absolutely no pressure in it, so it becomes the absolute zero reference point.
Any pressure on the atmospheric side will push the flexible membrane in, but higher pressure will push it in further.
Remember, high pressure in this case equals atmospheric pressure, about 101 kPa at sea level.
Now, attach a hose from the intake manifold of your engine to the open jar. Devise an electrical circuit to measure how far the membrane flexes, and you have the basic idea of how a MAP sensor works (fig. 18).
A - Hose fitting to manifold
B - Thin silicon diaphragm
C - Reference pressure chamber (Absolute vacuum, zero pressure)
D - Pyrex glass
E - Sensing resistors on silicon diaphragm
When would I ever measure a reading as low as 15 kPa?
The sensor is called a manifold absolute pressure sensor because its sensing element is connected to the intake manifold, either through a hose or a direct mount. When the engine is not running, the pressure inside the intake manifold is equal to atmospheric pressure, and the PCM will use this "engine not running" MAP signal as the BARO reading.
A running engine acts like a large vacuum pump. When the throttle is nearly shut, the pressure in the intake manifold is very low -- as low as 15 kPa at a high-speed, closed-throttle deceleration. As the throttle is opened, the pressure inside the intake manifold increases because the atmospheric pressure outside the intake manifold is rushing in, limited only by the engine's throttle blade opening.
The accompanying chart shows that low manifold pressure (engine idling) equals low MAP output voltage, and high pressure (engine at WOT or not running at all) equals high MAP output voltage.
What is the function of the three wires leading to the MAP sensor?
One of the wires provides a precise 5 volt power supply from the PCM. Another wire provides the ground circuit, grounded only through the PCM. The third is the signal wire, carrying the signal voltage generated by the MAP sensor to the PCM.
http://www.fastfieros.com/tech/map_sensors_and_how_they_work.htm
Hope this helped...
www.kronosperformance.com / 732-742-8837
yeah actually it does....
Just a another quickie.... the MAP, and MAF work together then, to figure out the A:F?
i was thinking that the MAF did the calcs, but i gues if ya dain't got one, then the MAP does it all!!!
the A:F gauges get attached to which one?
wait for it... wait for it... NOW GO!! ---> '02 LS Sport <---
Yahoo IM : buzz122 AIM : buzz122cav
we don't have MAF sensors. The MAP, IAT and O2 sensor work together to have the programed AF ratio..
Gilles
2.3 Ho
Ohhh...
Thanx....
wait for it... wait for it... NOW GO!! ---> '02 LS Sport <---
Yahoo IM : buzz122 AIM : buzz122cav
yup. it's either MAF ( most fords and nissans) or MAP. MAF does it all in one while MAP i personally consider to be more accurate. because you have your IAT's and of course the actual MAP sensor... speaking of which... hooray for positive intake manifold pressure 
I was a retard, and now I'm permanently banned.
GM has used both sensors in their vehicles as a backup for when the MAF can fail. So it is possible to see both sensors in a vehicle but not in our 3rd gen J-bodies, except for those that have done some extensive work to squeeze a V6 in their cars.
'99 2200 LS CX1 Sport
MAP seson and MAF sensor are different sensors that sense the same thing, as said above the map sensor senses pressure, no pressure computer knows your hard on the gas, heavy load on the engine, lots of negetive pressure (vacuum) it knows your more of less idling. The MAF is a mass air flow sensor, there is a heated wire inside inside MAF sensor, as air comes in it cools the wire down so it requires higher voltage to keep it at the same temp, so when your full throttle lots of air coming in cooling it down it cranks up the power to keep it heated to the same temp, so the computer knows its using more power right now so hey it must be full throttle/heavy load, when idling not much air passes it so doesn't take much to keep it hot so it sees lower voltage as less load, partial throttle/idle whatever. biggest problem with MAF sesnors is things like K&N filters, if you add to much of the oiling stuff it gets sucks in the intake, if it hits the MAF heated wire its gonna take out the sensor. Also its ALOT more difficult to diagnos a bad MAF then it is a MAP
thanks for the info.the rubber gasket on the map sensor was bad.i was loosing vaccum bad.got that fixed but the car is still running bad.it surges bad at low rpm.and i got a miss fire code all the time.
ooo...that is interesting. I have a S-AFC II that I was gonna hook up to correct my air/fuel when I get the throttle body work and cam put in. Now I know it will work.
I'll have a sig someday....................
Blackcav00 wrote:ooo...that is interesting. I have a S-AFC II that I was gonna hook up to correct my air/fuel when I get the throttle body work and cam put in. Now I know it will work.
Only suggestion is take it to a dyno or find someone with a wideband to tell you if you're running rich, lean or if you're a/f is fine before you start toying with it.
www.kronosperformance.com / 732-742-8837
i have a larger throttle body and a cam also.what is the S-AFC ll.is it expensive and what does it acually do?
Sheldon ONeill wrote:i have a larger throttle body and a cam also.what is the S-AFC ll.is it expensive and what does it acually do?
An SAFC-2 is an electrical tuning device that allows you to manipulate your computer to changing your signal for the injectors to either send more or less fuel.
It costs anywhere from $250-325 brand new.
As far as if it's worth getting, depends on if you're having any fuel issues. I would suggest taking it to a dyno tuning shop to get your a/f ratio checked.
www.kronosperformance.com / 732-742-8837
I could possibly have fuel issues once my engine is complete esp. since I am not running a cat right now. But I would definitely get it dynoed beforehand to see where I need to improve A/F and def. tune it on the dyno as well. Might as well do it right.
I'll have a sig someday....................
Blackcav00 wrote:I could possibly have fuel issues once my engine is complete esp. since I am not running a cat right now. But I would definitely get it dynoed beforehand to see where I need to improve A/F and def. tune it on the dyno as well. Might as well do it right.
Yea, put a cat on it unless you are boosted.
I was a retard, and now I'm permanently banned.
