MS-II show wrong rpm

[floods]

Hello all,

Today is my first try with my new MegaSquirt (V 3 board MS-II), the system work perfectly of the stimulator, but when i put it on the car the engine d'ont start and the RPM on Megatune show me approximately 2500 ~ 3000 RPM when i try to start the engine, that really a wrong value and i don't understand why ? i think the right value is about 200 ~ 250 RPM (stater speed).

The Megasquirt is installed to a V6 PRV engine 2.8 liters (a 90° V6) 2849 CC all other sensor work perfectly (IAT, ECT, TPS...... all ok, just the RPM), i use the (CKP) crankshaft position sensor (VR Circuit) this sensor is on the flywheel of the engine, i have try to invert the wire and adjust the R56 and R52, but i have all time the same problem.

I use the direct coil control circuit, and i have leave the original distributor.

The fuel line is ok (injector work and fuel go in the engine), same for the spark, i have spark on the sark plug, i don't know if i have it on the good time but i have spark.

On the first try the engine has try to run a little, but they don't start, i think this is because the RPM value is wrong.

I have check the crankshaft position sensor and they are ok, must have ~ 200 ohm (that ok).

Can someone help me ?

I have a week to make run this car, hope that will be ok

Thanks a lot.

[floods]

I just check the crankshaft position sensor voltage, i have ~ 0.7 Volt AC when engine cranking, it is ok for Megasquirt ?

Thanks

[floods]

Hi again

I have try to put a 10 Kohm resistor to the crankshaft position sensor wire, but i have exactly the same problem, this don't change anything.

It is possible that the original RPM gauge from the car do this problem ? because i think it use the same sensor, right ?

I have try again to put the Megasquirt on the stimulator and all is ok with it, this problem is only when i put it on the car.

The RPM gauge on Mega Tune is relatively stable, (don't jump and don't drop-outs) then i think that not a noise problem.

Hope really that anyone can help me

Thanks

[grippo]

If the rpm doesn't drop to 0 then please do not change resistor or change the VR sensor circuit. Such a large difference in rpm is due to a data configuration problem. For example if you told the ECU you have a regular distributor setup but you ran a toothed wheel, then it would think each tooth was 120 deg apart when actually they are only a few deg apart, so it will tell you the rpm is very high when actually it is not. Review your settings and be sure they match what you have in the engine. If you can't figure it out, post your msq file.

[floods]

Thanks for your reply.

Your right, i have make test today, it is better but i don't know exactly wath i must put in the ignition setting, today i have counted the number of teeth of the crank wheel, i have 60 teeth and 3 missing teeth (more long theet), i have have make a schema of the teeth (i have put in in line not in circle) here the link : http://www.evolussem.net/images/crank_wheel.jpg
If i count the missing teeth i have 63 teeth that right ? (i am not sure how the Megasquirt need that i count the missing teeth).

In my case i don't exactly understand what value i must put in Trigger Wheel Teeth, Missing Teeth, Skip Teeth and Delay Teeth.

My idea is that i must put 63 in Trigger Wheel Teeth, 3 in Missing Teeth, and 21 in Skip Teeth because (2*63)/6=21.
I think it is only right if i make a good interpretation of the number of teeth (i mean how i must count the missing teeth).

I am right ?

Let me know

Thanks a lot

[Matt Cramer]

Ok, if this is an even fire PRV engine, try setting 21 teeth and 21 skip teeth. Sounds crazy, but it's worked on Jeeps that use this wheel.

[floods]

Ok, if this is an even fire PRV engine, try setting 21 teeth and 21 skip teeth. Sounds crazy, but it's worked on Jeeps that use this wheel.

Ok thanks for your reply.
I will try that tomorrow and let you know.

Thanks again