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Discussion Starter #41
Sorry, what I meant was, if you have so much fuel in the engine that it's coming out of the intake manifold at the head, it's probably going past the piston rings into the oil and watering it down. Making the oil less lubricating.

But, if fuel is coming out of the intake manifold, that means there is a gap at the head to manifold flange and you have a vacuum leak. Vacuum leaks after the throttle body on these MAP engines will make the ECU confused to how much air is coming in vs fuel. But that would mean lean running, not rich. O2 sensor compensating? Dumping in more fuel. I'm not sure.
Ah I see thanks for the help I will get back to you tomorrow
 

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Discussion Starter #42
Sorry, what I meant was, if you have so much fuel in the engine that it's coming out of the intake manifold at the head, it's probably going past the piston rings into the oil and watering it down. Making the oil less lubricating.

But, if fuel is coming out of the intake manifold, that means there is a gap at the head to manifold flange and you have a vacuum leak. Vacuum leaks after the throttle body on these MAP engines will make the ECU confused to how much air is coming in vs fuel. But that would mean lean running, not rich. O2 sensor compensating? Dumping in more fuel. I'm not sure.
I used a multimeter on my map sensor and my signal wire showed 3.4 volts without any vaccum on the sensor, then used a vacuum pump and the voltage did drop. The signal wire should have 5 volts at atmospheric pressure if I'm not mistaken. Am I correct about this?
I will post a video of it running soon
 

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2-2.6v at atmosphere
1-1.6v with vacuum
3-3.6v low boost
4-4.6 high boost

If the pressure sensor is delivering 3.4v to the ecu, the ecu would be supplying WAAAY to much fuel. You may have just found yer problem.
 

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Discussion Starter #44
2-2.6v at atmosphere
1-1.6v with vacuum
3-3.6v low boost
4-4.6 high boost

If the pressure sensor is delivering 3.4v to the ecu, the ecu would be supplying WAAAY to much fuel. You may have just found yer problem.
Because i dont have patience, if I were to go to a junk yard and pull a map sensor off of a camry with the same connector would that work? Or are they made engine specific
 

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Because i dont have patience, if I were to go to a junk yard and pull a map sensor off of a camry with the same connector would that work? Or are they made engine specific
You'd need one that can read boost. Camry MAP sensors can't really do this.
 

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Because i dont have patience, if I were to go to a junk yard and pull a map sensor off of a camry with the same connector would that work? Or are they made engine specific
There is a chance if you could find one from a turbo vehicle that it would work. AFAIK these are generally 5v not 12v but there may be exceptions. Just make sure to cut the harness and take the connector plug.

Best solution is of course to replace but I get lacking patience. If you have access to an electronics supply and feel like making your own FCD you can use it to control the voltage the ECU see's from the sensor. Not a long term fix but you may be able to get it running enough to work out any other kinks while you wait for the part. Then once yer up and going it will be useful if you are tryna push boost limits.

here is the link. http://toymr2.tripod.com/fcd.html
it may be harder to track down the old radio shack items but most electronics stores should be able to cross reference.
 

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Discussion Starter #48
There is a chance if you could find one from a turbo vehicle that it would work. AFAIK these are generally 5v not 12v but there may be exceptions. Just make sure to cut the harness and take the connector plug.

Best solution is of course to replace but I get lacking patience. If you have access to an electronics supply and feel like making your own FCD you can use it to control the voltage the ECU see's from the sensor. Not a long term fix but you may be able to get it running enough to work out any other kinks while you wait for the part. Then once yer up and going it will be useful if you are tryna push boost limits.

here is the link. http://toymr2.tripod.com/fcd.html
it may be harder to track down the old radio shack items but most electronics stores should be able to cross reference.
I just decided to order a new one, but I followed that wire back to the ecu connections and found that the same signal wire from the map sensor was supplying 11.5v to the ecu? Is that correct? I could have also checked the wrong wire
 

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No. It should only be getting 5v.
5v power comes from VC pin#2 on plug B and goes to the:
PIM(B-11) - map sensor
VTA(B-23) - throttle position
THW(B-14) coolant temp
THA(B-22) air intake temp
THAM(D-10) intake manifold temp

EDIT: read this after post and realized these pins are the return signal, from VC you should have a B/R wire that splits to each sensor and supplies power. IDK if your wire color will match as you had the harness made but it should be easy to check what is connected to VC and what isn't This list is the entire 5v system and should be isolated and only connect from sensors to ECU, nothing more. (hopefully less confusing)

the grounds from those sensors then tie together and go to #18 on plug B (E2) (not tied to any other ground, should not have continuity with chassis or engine grounds)

sensor may be fine, may be blown from over voltage. its just clamping as much as it can with being supplied over 2x the voltage. make sure you have this wired correctly. I don't imagine that sensor is cheap and if you don't need it...... or if you do and hook it into 12v again the results arent gonna be good.

Keep at it Meng. You're making progress and learning as you go. It can be frustrating at times especially with needing to wait for parts but the reward at the end will be worth it. Few other things in life make me as happy as driving my '2. You'll get there too =D
 

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Discussion Starter #51
No. It should only be getting 5v.
5v power comes from VC pin#2 on plug B and goes to the:
PIM(B-11) - map sensor
VTA(B-23) - throttle position
THW(B-14) coolant temp
THA(B-22) air intake temp
THAM(D-10) intake manifold temp

EDIT: read this after post and realized these pins are the return signal, from VC you should have a B/R wire that splits to each sensor and supplies power. IDK if your wire color will match as you had the harness made but it should be easy to check what is connected to VC and what isn't This list is the entire 5v system and should be isolated and only connect from sensors to ECU, nothing more. (hopefully less confusing)

the grounds from those sensors then tie together and go to #18 on plug B (E2) (not tied to any other ground, should not have continuity with chassis or engine grounds)

sensor may be fine, may be blown from over voltage. its just clamping as much as it can with being supplied over 2x the voltage. make sure you have this wired correctly. I don't imagine that sensor is cheap and if you don't need it...... or if you do and hook it into 12v again the results arent gonna be good.

Keep at it Meng. You're making progress and learning as you go. It can be frustrating at times especially with needing to wait for parts but the reward at the end will be worth it. Few other things in life make me as happy as driving my '2. You'll get there too =D
Ok so your saying that my intake temperature (manifold) should be in pin (d-10) so if I were to test continuity from the signal wire from the sensor to plug d-10 I should hear a beep from my multimeter
 

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Ok so your saying that my intake temperature (manifold) should be in pin (d-10) so if I were to test continuity from the signal wire from the sensor to plug d-10 I should hear a beep from my multimeter
Yes. according to the diagram I have it should be a green wire from the ecu that originally went to a junction and then became a Black-Orange wire. I dont have the junction on mine, the wire just has those different colors with a splice where the junction would be.
 

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Discussion Starter #53
Yes. according to the diagram I have it should be a green wire from the ecu that originally went to a junction and then became a Black-Orange wire. I dont have the junction on mine, the wire just has those different colors with a splice where the junction would be.
Ok so I tested all of the other wires the map, throttle position and coolant temp sensor. They all are where they should be. Not the intake manifold temp sensor, I checked pin B-10 and got nothing I also checked all of the other pins and got nothing as well. Does ignition have to be on for these 2 wire sensors? And im not sure what other temp sensor you mean, the one for the n/a airbox?
 

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Ok so I tested all of the other wires the map, throttle position and coolant temp sensor. They all are where they should be. Not the intake manifold temp sensor, I checked pin B-10 and got nothing I also checked all of the other pins and got nothing as well. Does ignition have to be on for these 2 wire sensors? And im not sure what other temp sensor you mean, the one for the n/a airbox?
ignition doesnt have to be on for continuity between D-10 and pin 2 on sensor (you said B-10 so double check)
the other temp sensor is the one for the air box. ive also heard it referred to as the AIT (air intake temp) or simply intake temp...(I don't think the ECU cares about this one much but its good to have.) it should have a brown wire tied to B-18 and Red/Blue wire to B-22
 

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Discussion Starter #55
ignition doesnt have to be on for continuity between D-10 and pin 2 on sensor (you said B-10 so double check)
the other temp sensor is the one for the air box. ive also heard it referred to as the AIT (air intake temp) or simply intake temp...(I don't think the ECU cares about this one much but its good to have.) it should have a brown wire tied to B-18 and Red/Blue wire to B-22
Ah yes I was looking in B-10 I did find it in D-10 so all of that's fine.... dang it!
 

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Discussion Starter #56
ignition doesnt have to be on for continuity between D-10 and pin 2 on sensor (you said B-10 so double check)
the other temp sensor is the one for the air box. ive also heard it referred to as the AIT (air intake temp) or simply intake temp...(I don't think the ECU cares about this one much but its good to have.) it should have a brown wire tied to B-18 and Red/Blue wire to B-22
Just checked the voltage at the map sensor and at pin 11, both showing around 11-12v now... how would this even happen?
 

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The ECU has 5V at Pin 11 Plug g (PIM) and Pin 2 Plug g VC. Everything else connected to the earthing of the MAP sensor and others is all 5V too.

I may have missed it but are you getting another MAP sensor to test or replace the current one?
 

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Discussion Starter #58
The ECU has 5V at Pin 11 Plug g (PIM) and Pin 2 Plug g VC. Everything else connected to the earthing of the MAP sensor and others is all 5V too.

I may have missed it but are you getting another MAP sensor to test or replace the current one?
I did order a new map sensor from prime but they have taken a really long time to ship my parts recently, not very helpful with my car either. But they're a big company so cant expect too much. But all of this is pretty confusing a couple days ago I had 3.4v at the map and now 11ish? I cant make much sense of it
 

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Do you have the PDF's with the wiring diagrams and pin outs downloaded? I don't remember where I found them but if you need them I can send them to you.
Somehow the 12v system is tied into these sensors and you need to find and eliminate that source.
The VC(5volt positive) sends power from the ecu (B-2) out to the TPS and the MAP. Those two then should have another connection to a brown wire that also connects to the other sensors (THA,THAM, THW) and then goes to E2 (B-18) the third wire from the TPS and MAP sensors go back to the ECU and the other sensors connect to the ecu. Make sure no other wires are tied in and make sure the brown grown wires only tie into the ECU. There are other brown ground wires that are easy to confuse or that may be tied in.

I think the difference in reading was that you were originally reading the output and this time you are reading voltage input. I would start at the VC and follow it to make sure that it only connects to the TPS and MAP, if there is nothing extra tied in there, trace all the brown grounds for the 5v system and make sure they are only tied into E2.
after that you should only have the lines from the sensors the the actual inputs on the ECU, but you may have to go through each to make sure they didnt get shorted/tied into a 12v line.
 
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