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Discussion Starter #1
1991 5.0 Lx convertible . KOEO codes im getting are 22, 85, 51. I know that 22 is the BAP(map), but i need help testing it to see if its the wiring or the sensor. 51 , ECT sensor has open circuit. When i look at the ect sensor it only have two wires going into it which none are a ground. Please Help Me,
 

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Unless you have a meter that reads hertz, there is no real way to test the MAP/BP sensor. If you insure that the sensor is getting the proper reference voltage and ground, then its likely the sensor is bad. Make sure no vacuum is hooked to it as well.

ECT code is an open circuit code. With the sensor connector unplugged. Test the connector with a meter. One wire will have 5v, the other is ground. If you test to a body ground, and there is no 5v on the green wire then, the green wire is the issue, if there is 5v, then its likely the ground wire to the sensor.
 

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now that you have retreived codes and recorded them, clear codes and rerun on demand test, address the on demand codes first, then road test and reck codes if any others return address them as continuous codes. ect is a thermistor 1 wire is reference voltage 5.0 volts, other wire is signal return to PCM. test for 5.0 volts. use dvom to measure if you have 5 volts then ck for continuity on other wire to pcm connector. pulling the connector off with key on will set this code, so clear code and reck for hard code before testing the circuits to save time. MAP sensor has a slightly different test procedure so get a manual and test the system per manual, if it is a hard code. repost with drivability symptoms i.e. CEL, surging, stumble etc.
 

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Discussion Starter #4
I ran the codes 2 weeks ago on sunday. I was getting a maf low voltage as well as the same codes as i just posted above, it also failed the running test. On saturday, i took apart and cleaned with Sea-foam intake cleaner the throttle body, EGR, IAC, and replaced all the gaskets to them. I also cleaned the MAF with electronic cleaner. Yesterday after i ran the codes again. I got KOEO 22, 81, 51. The CM codes were 22, 51. There was only two CM codes. I didn't drive it for 50 miles between the time i put it all back together and before i ran the codes the next day. Also, yesterday it actually passed the running test. My car is completely stock, a/t, with 68,000 original miles. I dont know how the upkeep on it was , im pretty damn sure the spark plugs are the originals. It isnt cranking as long as it was 2 weeks ago, but it still seems a little sluggish and gas MPG is bad. I drive to and from work everyday. I got over 5 volts when i tested the ECT Sensor. From the back side of the connector for it .
 

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Discussion Starter #5
Thanks for the info too, slowly but surely i think im getting more confident that i wont have to pay somebody to fix this .
 

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Discussion Starter #6
If the BAP (MAP) is bad can I just get a map sensor and leave the vacuum off it? It does it have to be a bark sensor.
 

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Discussion Starter #8
those both are gonna make it run like **** right?? the gas mpg is way bad . Im gonna test the map sensor voltage and ground hopefully tonight ... If it ends up being bad, where is the best(least expensive preferably) place to order or buy one, Junkyard?? . I live in LA so i would assume theres gotta be some parts or used parts place down here . Thanks
 

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Discussion Starter #9
Ok , well i finally got some time tonight to test the wiring on the two sensors. The ECT gets a little less than 5 volts when grounded to to the ground from the back of the connector. Tested the ground with positive battery end, works as well. Now to MAP (BAP), from vacuum line nipple on MAP sensor, the wires i have are Brown/White, Green/Black, white/red orange? (Orange?). I have 5 volts from the black/white to the orange/white
. From the black/white to neg battery i have 5.03 volts. From the green/black to positive battery i have 12.?? volts. I can't find a good wiring diagram that shows my color wires and the connector. Hopefully, somebody on here can help me out. As for in the morning I'm going to pick one up from someone for a good price. I don't know about getting into to testing with hertz (a little too much for me ). Appreciate all the info thus far . Thanks
 

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Wire colors aren't important. On the MAP sensor connector. The first and third terminals are the power and ground. If you have 5v, there, then its likely the sensor is bad.

As for the ECT code, take the connector, off and install a paper clip across the terminals. Run codes, it should throw a 21 or 61 now. If so, the ECT sensor is bad.
 

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Discussion Starter #11
Well I went and got bought the ECT, and MAP sensors used for $30 from a mechanic i met on craigslist. I changed the MAP when i left Downtown LA and CEL was still on. But the car ran tremendously better(Way responsive) When i got back home i changed the ECT, and started it. NO MORE CEL at all. Tomorrow I'm going to have my buddy use his snap on OBD1 and run the codes on it just to make sure.
 

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Discussion Starter #12
Now I'm getting the CEL intermittently when driving . I hope it comes up with some thing when i run the codes tomorrow. Anyone have any general ideas?? Just curious as to what it could be now that wasn't a problem before.
 

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CEL sounds like EGR or Smog codes, you'll probably have to get the memory codes for that.

Do a search for base idle reset. See if that fixes your ideal. But you need to fix any codes first.
 
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