Definite tach solution for a, sorry, ANY diesel engine

[R.O.R-2.0]

i believe im going to play around with my setup a bit more today..

see if i cant get a tach reading from my cluster..

i know the cluster is good..

[snakemaster]

i used the crank pickup on my 1z mtdi ,its in a gasser 2.5 t4 transporter ,but now a mtdi wired up the sencer power from pump sol, and run the wire from no 2 pin to the gas taco , and have my  aftermarket diesel taco on to the w T , to compare gass taco on idle, reads 900rpm and the W one reads 650rpm m van dose ldle low. and  gaser at 3000rpm W at 2000rpm , tryed a small capacitor in line from no 2 pin  then a bit biger one ,just the same , need some way to get the  frequency down . i am not in to  electronics things bobers, but some one may be able to shed some light on this .

[R.O.R-2.0]

you positive your diesel tach is accurate?

i would lean more towards the gasser tach being accurate...

if its raining too hard, the diesel tach is in-accurate, and thats not cool..

my old audi 5000TD, the tach would quit working whenever you hit a puddle in the road..

then the belt would dry, and the tach would come back to life..

[libbydiesel]

The crank sensor on the AHU/1Z will give four pulses per rev.  The gasser 2.5 (5-cyl) tach will be looking for 2.5 ignition pulses per rev and thus the discrepancy.  A gas 4 cyl tach is looking for 2 pulses per rev.  I've been planning on using a flip-flop to cut the crank sensor output in half in order to drive a typical 4-cyl gasser tach. 

[bbob203]

The crank sensor on the AHU/1Z will give four pulses per rev.  The gasser 2.5 (5-cyl) tach will be looking for 2.5 ignition pulses per rev and thus the discrepancy.  A gas 4 cyl tach is looking for 2 pulses per rev.  I've been planning on using a flip-flop to cut the crank sensor output in half in order to drive a typical 4-cyl gasser tach. 

whats this flip flop you are talking about?

[libbydiesel]

It's one of the most basic logic circuits.

http://en.wikipedia.org/wiki/Flip-flop_%28electronics%29

[bbob203]

After reading some of that I short circuited. lol.. What would one use to implement a flip flop circuit to do what your describing to cut the 4 pulse signal into 2?

[ORCoaster]

I've been planning on using a flip-flop to cut the crank sensor output in half in order to drive a typical 4-cyl gasser tach. 

Well it might be this type of flip flop. 

[snakemaster]

aaa some info there would this flip flop do http://www.ebay.co.uk/itm/FLIP-FLOP-D-TYPE-SMD-74LVC1G175-Part-SN74LVC1G175DBVT-/390460792223?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item5ae946dd9f

or can i buy a set up ready to go , we have maplines , and rs hear , no rado shack 

[libbydiesel]

I'm not particularly electronics savvy, but I think that would work wired correctly. 

[R.O.R-2.0]

anyone have any idea about modifying the stock mk2 tach to accept a signal from a mag pickup?