Homer Posted May 4, 2007 Author Share Posted May 4, 2007 I'm back in the UK and ready to get this solved! I've tested the temp sensor, O2 sensor and crank sensor resistance and all are within spec (well the o2 was a little below at 1.3, but that can't be the cause). I've tested the crank position sensor at the ECU end and it was exactly the same as at the sensor. I want to test the O2 and ideally cam position sensors at the ECU, but it's not clear how to do this. The O2 sensor for example has two pins on the ECU, 48 and 71, I believe only one of these is the actual O2 sensor, but what do I do with the other end of my mulitmeter wire - would it go to earth? Same applies to the cam position sensors, they only have one pin on the ECU each. Edit - I have also removed the EMB and fields harness, just to rule out the EMB or bad wiring. As expected this didn't make any difference aside from making it a little more rich than before (if thats possible!) Quote Link to comment Share on other sites More sharing options...
bondango Posted May 4, 2007 Share Posted May 4, 2007 Darryl if you hold her to about 3.5K revs does she run any better?? Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Darryl if you hold her to about 3.5K revs does she run any better?? Hi Marty, no, it doesn't. It's still incredibly rich and chucks out clouds of black smoke. Quote Link to comment Share on other sites More sharing options...
bondango Posted May 4, 2007 Share Posted May 4, 2007 Did you try a new/different Map sensor, or check the Vac line to it? looking at that Vid, it looks similar to faulty map sensor. Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Did you try a new/different Map sensor, or check the Vac line to it? looking at that Vid, it looks similar to faulty map sensor. It does indeed look like that. All VAC pipework has been checked and replaced. The map sensor was swapped with one from a known working car by Phoenix but this didn't make any difference. The strange thing is, that it runs pretty much the same with the Map sensor disconnected! Edit to add: The signal seen at the ECU from the Map sensor is correct Quote Link to comment Share on other sites More sharing options...
tDR Posted May 4, 2007 Share Posted May 4, 2007 Did you rule out the MAP sensor signal source being inappropriately dampened? Do you have a THOR FCD (or other FCD for that matter) still in the loop somewhere? Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Did you rule out the MAP sensor signal source being inappropriately dampened? Do you have a THOR FCD (or other FCD for that matter) still in the loop somewhere? Cheers, Brian. Ah yes, thanks for the advice on that. The MAP sensor vac source was set up correctly but I had my Greddy pressure sensor on an undampened line. This is now corrected but it's not linked to this issue. The Thor FCD has been removed. Quote Link to comment Share on other sites More sharing options...
dandan Posted May 4, 2007 Share Posted May 4, 2007 Have you tried an ecu swap at all? I have a facelift (non vvti) 6speed one if you want to try it but am not in UK till sunday and I don't know if it's identical to pre facelift. Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted May 4, 2007 Share Posted May 4, 2007 Hey Mate sorry to see your having some bad problems Ok i have seen this problem before on a mr2 when i went to map it the car was running just the same as your, Badly overfuelling and would barely run every so often. I spent ages checking for vac leak and bad components just like you are and what it was is there is a spider earth which is normally underneith the inlet manifolds on toyotas. This is the ground for the ECU and the sensors in the engine bay. Now there are more but the only one i exspect you have touched around that area is this one. Basically it was not tight and had got dirty and was causing the car to run like crap. I would suggest you check all the earths round the engine bay and the ones by ecu. If you have no luck then give me a shout i have a spare 6sp ecu as you could have killed a resistor in yours when wiring emanage up as the ecu connectors are not great and you could have moved one. I also have a spare powerfc ecu available to me which i could plug in and instantly tell you where the problem is as can view all sensors and controller everything Quote Link to comment Share on other sites More sharing options...
tDR Posted May 4, 2007 Share Posted May 4, 2007 Have you checked out the Intake Air Temp sensor? (Might have been mentioned already so sorry in advance!) I've seen these cause this kind of issue on other cars. I've never had to deal with on my Supra so can't help you with the specifics... I know the USDM model has it as part of the MAF assembly but it's likely on the intake plenum somewhere on our JDMs. Also, this may be blindingly obvious but are you sure your ECU multiplug is completely secured / well seated totally flat? They can seem in and cause all kinds of issues you'd tear your hair out at because they're not firmly seated. The screw in connector is a pain as you can never really tell when it's completely in. Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
tDR Posted May 4, 2007 Share Posted May 4, 2007 Good idea on the earths Ryan, I've also experienced similar to what you describe. Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Have you tried an ecu swap at all? I have a facelift (non vvti) 6speed one if you want to try it but am not in UK till sunday and I don't know if it's identical to pre facelift. I've not tried another ECU, but this is a step I'd really like to try. Many thanks for the offer, I'll see how I get on this weekend but will be in touch Sunday/monday if I'm still having problems. Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Ok i have seen this problem before on a mr2 when i went to map it the car was running just the same as your, Badly overfuelling and would barely run every so often. I spent ages checking for vac leak and bad components just like you are and what it was is there is a spider earth which is normally underneith the inlet manifolds on toyotas. This is the ground for the ECU and the sensors in the engine bay. Now there are more but the only one i exspect you have touched around that area is this one. Basically it was not tight and had got dirty and was causing the car to run like crap. I would suggest you check all the earths round the engine bay and the ones by ecu. If you have no luck then give me a shout i have a spare 6sp ecu as you could have killed a resistor in yours when wiring emanage up as the ecu connectors are not great and you could have moved one. I also have a spare powerfc ecu available to me which i could plug in and instantly tell you where the problem is as can view all sensors and controller everything This earth point has been mentioned before. If its the same one I'm thinking of its wired to the Inlet runners, not the inlet manifold itself. I did not touch this during the build, but I'm not ruling it out! It's a nightmare to get to (have to remove the inlet manifold) but I might wire that direct to the battery negative just to make sure. Thanks again for the offer, after our chat on ECU's the other night it sounds like the powerfc can do a lot more than my current setup. Again, i'll see how things this weekend with the rest of the tests, if it's not solved I'll be in touch! Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Have you checked out the Intake Air Temp sensor? (Might have been mentioned already so sorry in advance!) I've seen these cause this kind of issue on other cars. I've never had to deal with on my Supra so can't help you with the specifics... I know the USDM model has it as part of the MAF assembly but it's likely on the intake plenum somewhere on our JDMs. Also, this may be blindingly obvious but are you sure your ECU multiplug is completely secured / well seated totally flat? They can seem in and cause all kinds of issues you'd tear your hair out at because they're not firmly seated. The screw in connector is a pain as you can never really tell when it's completely in. Cheers, Brian. I was having a read of the Toyota service manual eariler (CJ's ones which are USDM based). It mentioned the air intake temp sensor as part of the troubleshooting but I don't think the JDM model has one. It's fitting in the airbox on the US models, but isnt there on the JDM ones. Regarding the plug, I am certain this is secure, I've removed and refitted it several times (as has Matt Harwood) and it fits great. The EMB sees all the right signals from the various sensors so at least appears to be okay. Quote Link to comment Share on other sites More sharing options...
Steve Posted May 4, 2007 Share Posted May 4, 2007 I am still no closer with mine Darryl, so will be watching this thread for any ideas. I have changed the ECU that didnt make a difference. Mine just seems to be intermittent, but is overfuelling most of the time, just not as bad as yours. Good Luck Quote Link to comment Share on other sites More sharing options...
Steve Posted May 4, 2007 Share Posted May 4, 2007 I was having a read of the Toyota service manual eariler (CJ's ones which are USDM based). It mentioned the air intake temp sensor as part of the troubleshooting but I don't think the JDM model has one. It's fitting in the airbox on the US models, but isnt there on the JDM ones. Regarding the plug, I am certain this is secure, I've removed and refitted it several times (as has Matt Harwood) and it fits great. The EMB sees all the right signals from the various sensors so at least appears to be okay. The Air Intake Temp sensor is in the Plenum, just in front of the MAP sensor on a J Spec Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Mine just seems to be intermittent, but is overfuelling most of the time, just not as bad as yours. Thanks mate. Is yours intermittant as in one day its fine, next it overfuels? In your conversations with Ian did he detemine that the injector durations were higher than expected? This seems to be the cause of the issues I have, just wonder if they are rleated... Quote Link to comment Share on other sites More sharing options...
Steve Posted May 4, 2007 Share Posted May 4, 2007 Thanks mate. Is yours intermittant as in one day its fine, next it overfuels? In your conversations with Ian did he detemine that the injector durations were higher than expected? This seems to be the cause of the issues I have, just wonder if they are rleated... Yeah the Emanage sees the injector durations coming in then obviously the fudged signal going out. The durations from the ECU are higher than what they were when it was mapped (by 1.2ms ish i think). When i say intermittent i mean on one test run it goes fine, then next run it overfuels. No real pattern to it. But most of the time it overfuels. Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 The Air Intake Temp sensor is in the Plenum, just in front of the MAP sensor on a J Spec Ah yes, I know the one, I'll test it tomorrow. BTW Quote Link to comment Share on other sites More sharing options...
Steve Posted May 4, 2007 Share Posted May 4, 2007 Its 48 and a earth from memory. 71 is the heater i believe. Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Its 48 and a earth from memory. 71 is the heater i believe. How do I measure the resistance the ECU is seeing? There are two wires on the sensor itself so I just measure across the two to get the resistance. How do I do this at the ECU end - there is only one wire? Quote Link to comment Share on other sites More sharing options...
Steve Posted May 4, 2007 Share Posted May 4, 2007 How do I measure the resistance the ECU is seeing? There are two wires on the sensor itself so I just measure across the two to get the resistance. How do I do this at the ECU end - there is only one wire? Its is definitely Pin 48. So hold one lead of your meter on pin 48 and the other on a Earth Screw (ground). That should work. Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted May 4, 2007 Share Posted May 4, 2007 well let me know how you get on and if still no good after weekend i will pop over but might have to be week night or sunday as saturdays and fridays im busy till july with mapping and work Quote Link to comment Share on other sites More sharing options...
Homer Posted May 4, 2007 Author Share Posted May 4, 2007 Its is definitely Pin 48. So hold one lead of your meter on pin 48 and the other on a Earth Screw (ground). That should work. Ah, thanks mate well let me know how you get on and if still no good after weekend i will pop over but might have to be week night or sunday as saturdays and fridays im busy till july with mapping and work Cheers Ryan, I'll def. be in touch. I work from home so am here most of the time. I'm happy to pay for your time & costs if you make the journey over. In the mean time, does anyone think it's worth reinstalling the stock injectors? This should at least rule out the injectors as the cause, but it's not some I do lightly as I find it real time consuming (8 hrs each time) changing them! Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted May 4, 2007 Share Posted May 4, 2007 Did you have the injectors flowed and cleaned before use at a well known company? Quote Link to comment Share on other sites More sharing options...
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