91 NA MS2 -- 2U and 2V weird voltage
07-02-2018, 10:38 AM
#22
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i was assuming the measurements were happening without the injectors in place, measuring at the connectors themselves.
Last edited by Braineack; 07-02-2018 at 10:57 AM.
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07-02-2018, 10:40 AM
#23
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This is the only way I know of for the MS to control the FP on an early NA without chassis harness modifications. If there are no harness modifications, and the MS isn't configured to control the FP via 1C, and the AFM has been removed, You're gunna have a bad time.
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07-02-2018, 11:04 AM
#25
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i wire FP to 2O and if you remove the AFM, you simply jump the 2O pin to the FPR pin in the AFM connector to connect the MS to FPR directly.
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07-06-2018, 03:56 AM
#29
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Hello again,
I was away travelling for work, so thank you both for the very informative discussion.
I think my block of texts and a bit unreadable formatting of the said blocks were a bit confusing
To clarify : 2u and 2v voltage to the ground is measure with the injectors (at least one injector but measured in both scenarios anyhow). With the injectors unplugged, I read zero voltage in the working bank but same voltage in the problem bank
I also checked injector wiring (from 2u and 2v to plugs and ground) without ecu and without power, no short to ground, very similar resistance values. I measured red/white wires too but they are all fine, consistent with other 12v sources on the car.
At this point I am trying to get the local specialist to change u7 mosfet and will try again to see if that solved the issue. Hopefully it is a bit clear now.
Regarding fuel pump, STSIGN is removed. I will check 1C for the pump, when I put ms in the car again.
I was away travelling for work, so thank you both for the very informative discussion.
I think my block of texts and a bit unreadable formatting of the said blocks were a bit confusing
To clarify : 2u and 2v voltage to the ground is measure with the injectors (at least one injector but measured in both scenarios anyhow). With the injectors unplugged, I read zero voltage in the working bank but same voltage in the problem bank
1- Most obvious observation, (that was very noob of me to not do the first time because I was measuring voltage across terminals with all inj unplugged - not to the ground.)
Anyhow: Yellow/black - both injectors unplugged, KOEO-, still has the same -1v battery voltage to the ground. ---- I mean battery voltage value minus one volts (i.e. 10v etc.) basically, there is voltage despite no resistors.
Yellow wire, good bank, does not read any voltage when both injectors are unplugged . (which I think is the correct behavior)
Only one injector of each bank plugged: firing bank reads same as battery (I was boosting the battery last time) - shitty bank reads -1v battery.
--Basically, without any resistors on the line, it still reads voltage to the ground.
Anyhow: Yellow/black - both injectors unplugged, KOEO-, still has the same -1v battery voltage to the ground. ---- I mean battery voltage value minus one volts (i.e. 10v etc.) basically, there is voltage despite no resistors.
Yellow wire, good bank, does not read any voltage when both injectors are unplugged . (which I think is the correct behavior)
Only one injector of each bank plugged: firing bank reads same as battery (I was boosting the battery last time) - shitty bank reads -1v battery.
--Basically, without any resistors on the line, it still reads voltage to the ground.
At this point I am trying to get the local specialist to change u7 mosfet and will try again to see if that solved the issue. Hopefully it is a bit clear now.
Regarding fuel pump, STSIGN is removed. I will check 1C for the pump, when I put ms in the car again.
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07-09-2018, 08:19 AM
#32
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yeah, and just see if you still read voltage on the injector ground side.
if you then plug in the MS and do the same test exactly the same, and you do read voltage on the ground side, at least we know we've narrowed it down to being a problem with the MS (which we probably already know at this point).
Next step would be opening the case and getting good pictures inside the top and bottom of the board and the microsquit module.
if you then plug in the MS and do the same test exactly the same, and you do read voltage on the ground side, at least we know we've narrowed it down to being a problem with the MS (which we probably already know at this point).
Next step would be opening the case and getting good pictures inside the top and bottom of the board and the microsquit module.
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07-25-2018, 03:41 AM
#33
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Ok guys, first of all thanks to both of you for your support. We have a resolution (at least regarding this problem 
)
Edit never mind the spoiler. The car was flooded with fuel completely! Injectors are being removed and sent for testing but it is probably ms :( oh well.
)- Firstly, tested with ecu removed, battery connected, key on, both injector ground side reads the same battery voltage to the ground. There is no difference between them with ecu removed
- I managed to reach the guy and very thankful to him. When trying to remove the mosfet, it actually fell apart, despite not showing any visible signs of heat damage. He replaced the mosfet with a "similar" one. He mentioned that reaction times may be different but since this is injection, not ignition, should not be critical.
- ECU showed same voltage symptoms on the bench with 12v power supply and resistors on the ground side (broken mosfet - U7 - was drawing voltage when the working side did not)
- Replaced the mosfet, got exact same behavior on the bench.
- Put the ECU on the car, did output and led tests, injectors were firing properly. Checked from my last year's log that my duty cycle did not exceed 49%, just to make sure that mosfet is not overworking. Started the car, voila !
Spoiler
Last edited by evotr; 07-27-2018 at 05:57 AM.
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07-28-2018, 09:46 AM
#34
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Hello again,
Just to get closure on the issue: I checked at the shop, now the voltage problem have switched over to the working bank. But instead of 1v below positive wire, it showed 5+ volts. Furthermore, when you check the trigger wire without the injecotrs connected, this bank now shows some milivolts. Funny enough, new mosfet acts exactly as it should.
Regardless: Injector got stuck open, flooded, bent rods (as far as we know for the moment). Funny enough, all the cylinders are flooded. And even by checking with a stick, 2 and 4 are 2-3 mm lower than 1 at their TDC. Anyhow, decided to hibernate the car while sorting new parts since opening up everything is pointless at this point, as I cannot get anything from US within a month minimum and then some.
Thanks all for your inputs. I will not open the engine until I get some new rods, new injectors (probably the ev14 pnp kit) and be sure that MS is sorted out. At that point, if the pistons are f*ed up, than go for lower comp pistons.
Ps. I "felt" that I should have gotten both mosfets changed but anyhow, the guy was also a hobbyist so can't blame anyone but myself. After a lot of abuse with emanage and 200+ crank hp with good fuel for 20.000 km's, I managed to kill the engine in the most unexpected way
Any advice on setup, MS etc. is welcome at this point. Maybe I will open a build topic at some point.
Just to get closure on the issue: I checked at the shop, now the voltage problem have switched over to the working bank. But instead of 1v below positive wire, it showed 5+ volts. Furthermore, when you check the trigger wire without the injecotrs connected, this bank now shows some milivolts. Funny enough, new mosfet acts exactly as it should.
Regardless: Injector got stuck open, flooded, bent rods (as far as we know for the moment). Funny enough, all the cylinders are flooded. And even by checking with a stick, 2 and 4 are 2-3 mm lower than 1 at their TDC. Anyhow, decided to hibernate the car while sorting new parts since opening up everything is pointless at this point, as I cannot get anything from US within a month minimum and then some.
Thanks all for your inputs. I will not open the engine until I get some new rods, new injectors (probably the ev14 pnp kit) and be sure that MS is sorted out. At that point, if the pistons are f*ed up, than go for lower comp pistons.
Ps. I "felt" that I should have gotten both mosfets changed but anyhow, the guy was also a hobbyist so can't blame anyone but myself. After a lot of abuse with emanage and 200+ crank hp with good fuel for 20.000 km's, I managed to kill the engine in the most unexpected way
Any advice on setup, MS etc. is welcome at this point. Maybe I will open a build topic at some point.
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