RPM failure around 7000 rpm

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Leistung Elektronik
MS/Extra Newbie
Posts: 11
Joined: Wed Mar 16, 2005 2:29 pm

RPM failure around 7000 rpm

Post by Leistung Elektronik »

Hi, i have a problem with the motor at around 7000 rpm.
I run the motor with msns-e 26h4 code, alpha-n (race cam), 36-1 wheel, lm1815 signal conditioner, 2 VB921 and edis coils (4 tower style).

The tach gets crazy and i have scoped the vb921 signal get lost of sync.

Adding resistance to the VR sensor i have rised the fault from 3000 rpm to 7000, but still there.

I appreciate some help or post from anyone that have the same problem.

Thanks
Mikymar
Fiat 1.6L Turbo @ 30 psi - MSnS Extra whit CDI
soon Ford 2.5L Turbo
subie4me
Experienced MS/Extra'er
Posts: 177
Joined: Sat Jun 19, 2004 2:20 pm
Location: southern California

Post by subie4me »

If you haven't already done it, try putting a 390 ohm resistor across the vr input to the lm1815 circuit.. I had to do this to make mine work properly.
Turbo motors I've squirted. 4cyl subarus, 6 cyl subaru with vvt&vvl, honda3.5 with vtec, aircooled vw's, toyota v8, 2.5l autocraft, turbo intercooled yamaha rhino, more to follow
Leistung Elektronik
MS/Extra Newbie
Posts: 11
Joined: Wed Mar 16, 2005 2:29 pm

Post by Leistung Elektronik »

have you the same problem?
Mikymar
Fiat 1.6L Turbo @ 30 psi - MSnS Extra whit CDI
soon Ford 2.5L Turbo
subie4me
Experienced MS/Extra'er
Posts: 177
Joined: Sat Jun 19, 2004 2:20 pm
Location: southern California

Post by subie4me »

Mine had a very noisy signal that really cleaned up by adding the resistor.. You say that ypu already put in the resistor. What value was it? If it improved some, then mayby you shiuld try lowering the resistor value some more.
Turbo motors I've squirted. 4cyl subarus, 6 cyl subaru with vvt&vvl, honda3.5 with vtec, aircooled vw's, toyota v8, 2.5l autocraft, turbo intercooled yamaha rhino, more to follow
Leistung Elektronik
MS/Extra Newbie
Posts: 11
Joined: Wed Mar 16, 2005 2:29 pm

Post by Leistung Elektronik »

VR signal have a little noise, but after the lm1815 the signal is perfect, likewise wenn the motor run at 7000 rpm and the ignition gets crazy...
The coil was not good grounded and the VB921 were to the chassis grounded. Now i will put all together with a common ground. Perhaps there was the mistake.
I will test too with the parallel input resistor.

Thanks
Mikymar
Fiat 1.6L Turbo @ 30 psi - MSnS Extra whit CDI
soon Ford 2.5L Turbo
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