BMW VTPS 6pin problem
#1
BMW VTPS 6pin problem
Hey guys and gals, have a problem im hoping you might be able to shed some light on. I have a megasquirt pnp, with a bmw e30 vtps conversion. When the car ignition is on and running, the vtps works correctly, the throttle position and ADC is read correctly when i change the actual throttle position. However as soon is the car is running, the throttle ADC and position in megasquirt fluctuates wildly even when the throttle is closed.
any thoughts? dont think its the tps because as i said it works correclty when the igntion is on but the car is not running. im lost....
cheers
justin
any thoughts? dont think its the tps because as i said it works correclty when the igntion is on but the car is not running. im lost....
cheers
justin
#2
Boost Pope
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My first thought is a grounding problem. When the engine is running, there's a lot of pulsating current running through some of those wires.
My second thought is that the TPS has some mechanical problem in which the engine's vibration causes movement of some internal part.
My second thought is that the TPS has some mechanical problem in which the engine's vibration causes movement of some internal part.
#8
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If you connected the Vref pin of the MS (pin 26) to the red wire at 1N, and you connected the TPS pin of the MS (pin 22) to the green/white wire at 2L, and also assuming that these wires are connected to the correct terminals at the TPS itself, then yes, you should have a steady 5v on the red wire and 0-5v on the grn/white wire.
Disconnect the TPS and test the red wire again. If it goes to +5, then you have a problem on the TPS end. If it does not, you have a problem on the MS end.
#10
Hey joe,
Info helped out thanks. Turns out for some reason i'm not getting the 5v from the ref wire from the megasquirt. I spliced in a 5 volt regulatore, took 12 volts from a nearby source and powered the tps with the 5 volt regulator. Worked a treat for the TPS ADC. have a range of 35 to 255 at wot. (the megasquirt apparently had the VTPS mod done to the board by diyautone, only thing i can think of is that over time something has gone amiss in the board? as all the other connections work fine, i.e. ground and signal wire.)
megatune picks up the TPS ADC a treat too. but now the throttle position gauge in megatune doesnt pic up throttle position (dont know how thats possible as id have thought the throttle position % was based on the tps ADC?). but having said that it appears that megatune only takes inputs from the TPS ADC not % of throttle so i think i should be fine without that. Anybody care to inform me otherwise? do i need throttle position %?
Justin
Info helped out thanks. Turns out for some reason i'm not getting the 5v from the ref wire from the megasquirt. I spliced in a 5 volt regulatore, took 12 volts from a nearby source and powered the tps with the 5 volt regulator. Worked a treat for the TPS ADC. have a range of 35 to 255 at wot. (the megasquirt apparently had the VTPS mod done to the board by diyautone, only thing i can think of is that over time something has gone amiss in the board? as all the other connections work fine, i.e. ground and signal wire.)
megatune picks up the TPS ADC a treat too. but now the throttle position gauge in megatune doesnt pic up throttle position (dont know how thats possible as id have thought the throttle position % was based on the tps ADC?). but having said that it appears that megatune only takes inputs from the TPS ADC not % of throttle so i think i should be fine without that. Anybody care to inform me otherwise? do i need throttle position %?
Justin
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Zaphod
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10-26-2018 11:00 PM