Loss of connection MGF 1999 MEMS1,9

Hei I have now used the Pscan for the second time, on the same problem. Crank no start, with a sudden stop on the road. I have crank shaft fault in the Pscan but RPM does puls as I crank the car. Pscan falles out during turing og engine, and does want to reconnect to the PC I must be doing somthing not correct, please give advise. I have fuel and 3 bar on fuel rail I have clikking on the fuel injektors I have spark on the pluggs If it was the camshaft sensor will I then have injektors and spark this is a car with rotor not cam sensor. MEMS1,9
Does the Coil or crankshaft sensor give the RPM in the car as this is moving.

You have apparently reliable sparks and injection signals and repeated crank sensor errors. I think that speaks for itself. I think I would consider the crank sensor to be suspect and replace it.

Thanks for the feed back I have measured the volt in to the crank sensor now to 0,4 volt I believed it should be around 1,5volt. I can not get to the sensor to measure the Ohm of the sensor but the spark plug are wet. I pulled out all the plugs put on jumper cables to an extra battery and crank the engine. I got connection with the crank sensor and 201 RPM om Pscan. Put plugs but after I have no RPM or connection to the crank sensor.

I assume it did come back due to the the engine rev speed, Still the sensor or el cables does any one know the Voltage out from the MEMS to the crank sensor?

0,4volt I believe is very low. I will start getting the sensor out if the low voltage is correct may be best just to change the sensor.

pscan dropping out during engine cranking is known problem that I am working on.
It varies with the car, and is less likely to happen if you have a strong battery.
I also made an experimental cable to feed in 12V to the pscan box from an alternative power source (it worked quite well from a DeWalt 12V power tool battery) and that also seems to work.
On my vehicles it doesn't happen, but then I have a habit of fitting the biggest battery that will physically fit in my cars (for example the Rover 25 1.6 K-series has a diesel battery in it).

pscan.uk wrote:

but then I have a habit of fitting the biggest battery that will physically fit in my cars.

I do the same, I see no point in piddley wimpy little toy batteries, like most OEM offerings (they're chosen on price not performance)
And if I can relocate a minor component to allow an even bigger battery to be fitted then so be it!

It depends on how much use I make of the car. A plaything doesn't get used in Winter and intermittent use will kill a battery in three years anyway so I wouldn't bother but a daily is different. I choose the battery based on the charging capacity of the alternator. As an aside, when I was a starship captain*, one of the colleagues asked if anybody had jump leads to start his Subaru Justy. I had. He then asked if my battery would be big enough. I lifted the bonnet to show a battery fully twice the size of the Justy's powerplant. "Think so, don't you?"


*CX driver.

Hi do you have a photo or DWG of the modification you have done to bring in a stable12vDC supply to the pscan.

Hi please note that I found out that fuse 12 supplies the Pscan thru the OBD. I pulled the fuse and supplied a wire lead from a different car battery to the fuse out toward the OBD contact and ground from the battery to the car chassis. Now as this battri had no voltage drop during cranking of the engine the Psan worked fine. Only thing is that you are then not measuring out battery voltage dure testing as it is reading the stand alone battery.

Happy MGF user wrote:

Only thing is that you are then not measuring out battery voltage dure testing as it is reading the stand alone battery.

Do you mean if you look at battery voltage in live data from the engine ECU? That's what the ECU says that the battery voltage is, not the voltage supplying pscan.

OK I am corrected, that is good info. I will connect up and measure the volt then I can se if (how mush voltage drop) I have on the wiring to the ECU.