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| MAP Sensor testing | |
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| Tweet Topic Started: Sep 10 2010, 07:16 AM (7,443 Views) | |
| dayle1960 | Sep 10 2010, 07:16 AM Post #1 |
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Fastest Hampster EVER
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What is the procedure for testing the MAP sensor? Also close in line with the MAP sensor is a fuel filter. Can this filter be tested? thanks terry |
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| Memphis metro | Sep 10 2010, 07:37 AM Post #2 |
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Are you getting a map sensor code? If so which code? This determines which test to perform on your sensor. If your engine is having driveability problems and you think it is the map sensor but have no codes, disconnect the electrical connector to the map sensor and if your engine runs better then replace the sensor. Other than check your little filter you can buy a inline filter at the parts store for the cheap. |
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| metroschultz | Sep 10 2010, 08:36 AM Post #3 |
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Please just call me; "Schultz"
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That little filter is a spark arrester/pulse dampener. It keeps the map sensor safe in the event of a backfire. I am not sure you can test it. I would just check to make sure it flows smoothly. |
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| mwebb | Sep 10 2010, 11:47 AM Post #4 |
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FOG
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3 wires to MAP sensor on one end labled is 5 volts must be 5 volts dead nutz on the other end labled is ground must be within 50 millivolts of battery negative 1 is signal . the center pin peak signal with key on engine off OR WOT about 3.6 volts this MAP sensor will read pressure above BARO over 3.6 volts .... but it is UNknown if the ECM will read it low value at hot idle about 1.6 volts headlights on to 1.7 volts headlights off higher with heater blower on or any additional loads at decel coasting down hill in gear about 1.4 volts signal values at 300 feet above sea level . higher elevation will INCREASE signal voltage value s a wee bit , 5volt and ground must never deviate from values above ===================== the little frantinizer in the vacuum line is a restriction orifice , it dampens the amplitude of individual vacuum pulses from each cylinder generated during the time the intake valve is open . it could also stop any spark s that may be present in the vacuum line ..... i guess , i had never heard of that particular use for it . Edited by mwebb, Sep 10 2010, 11:55 AM.
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| Memphis metro | Sep 10 2010, 11:57 AM Post #5 |
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I read somewhere as well it protects the map sensor from fumes and oil. It would be intresting to tear one of these apart to see the internal contents. It do look like a inline filter. |
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| dayle1960 | Sep 10 2010, 04:13 PM Post #6 |
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Fastest Hampster EVER
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Metroshultz, enginedoctorgeo, mwebb, thanks for your concise answers. I feel if ALL posters with questions such as mine would 1. State your problem in the subject line CLEARLY, 2. be accurate with the problem you are having in the body of your post, and 3, ask for a specific answer from one of the guys on this forum then the answer should be readily appearant. As an added benefit maybe someone like my self won't have to look to far into the search feature in order to get the answer we need 6 months from now. It is so much easier to peruse the title of threads instead of individual words within the body of the post. So once again, thanks all for the responses. terry |
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| dayle1960 | Sep 10 2010, 04:49 PM Post #7 |
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Fastest Hampster EVER
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Enginedoctorgeo: I pulled the plug out of the MAP sensor and the engine died. I tried it again and it died again. Do I need a new sensor? mwebb: Here are the results:: On the wiring harness connector from the ecu, engine,.... with the key on and engine off. The pin closest to the firewall has 13.9 mV. The center pin has 4.9V. The pin closest to the front of the engine has 5.0V. I tried to test the MAP sensor. I did not get any readings, but then I don't know how to test the sensor, but I guess I did the wiring harness connector correctly. As far as the inline filter, I disconnected it from the TBI and the MAP sensor. I blew through the bottom end and there was no restrictions. Felt like blowing through a straw. Thanks terry |
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| dayle1960 | Sep 12 2010, 08:12 PM Post #8 |
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Fastest Hampster EVER
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bump... |
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| mwebb | Sep 12 2010, 08:56 PM Post #9 |
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FOG
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http://geometroforum.com/topic/2680128/1/ you must connect to the MAP sensor with the MAP sensor connected in the harness first key on engine off then - then with the engine running use T pins values are in my previous post |
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| Memphis metro | Sep 12 2010, 10:15 PM Post #10 |
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(I pulled the plug out of the MAP sensor and the engine died. I tried it again and it died again. Do I need a new sensor?) Mitchell online says if your engine runs better after disconnecting it, replace it. I would say dying isnt better so do not replace it. Did you have any map sensor codes before you pulled the plug? |
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| dayle1960 | Sep 13 2010, 05:01 PM Post #11 |
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Fastest Hampster EVER
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no, it was not throwing a code before I unplugged it. I unplugged it and NOW it is throwing a couple of codes. MAP sensor code and vacuum leak. It will clear up. It did before. |
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| dayle1960 | Sep 14 2010, 05:41 PM Post #12 |
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Fastest Hampster EVER
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Yep, I disconnected the battery and low and behold the CEL cleared up. |
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| mwebb | Sep 14 2010, 09:33 PM Post #13 |
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FOG
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stop doing that it will not help your symptom - you waste time waiting for self testing to run what is 02 sensor voltage at hot idle and at 2k rpm hot should be cycling from 150 to 850mv (millivolts) .15 to .85 volts and back in 100 milliseconds or less black wire in the bundle of 4 to the front 02 sensor use T pin to connect |
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| Memphis metro | Sep 14 2010, 09:37 PM Post #14 |
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We have never heard what the symptom was! He was just asking about how to test it. LOL |
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| mwebb | Sep 14 2010, 10:09 PM Post #15 |
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FOG
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that s true .... but what ever it is bitch slapping the ECM by interrupting supply is not going to improve it |
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