gday,

been a while since ive been on here but anyway.

i think im experiencing a problem with my dizzy.
im using it as a Crank Angle Sensor to my Microtech Mtx-8 but it seems to be giving mixed signals and its resulting in erratic timing.

Its pretty much all over the shop at the moment and its making the car difficult to start and keep running, and its miss firing all the time.

The dizzy is a stock Fj20et item. Is there anything that needs to be done to get it to work better, or any way to test/have it setup correctly?


cheers,

blayne

make sure the signal cables from the dizzy are nowhere near any of your spark leads. The cable should be a shielded type also, wrapping them in aluminium foil sometimes helps.

thanks damo,

ill check that it is clear of the leads.
i know for a fact it is shielded with a woven metal sheath that surrounds the 4 wires, and that is covered witha plastic tube.

is it ok to have the dizzy wiring harness running with the rest of the microtech harness?

cheers,
blayne

Yeah, the main things to avoid is obviously running them near the spark leads, and if you have CDI ignition, you need to keep them away from the power wires running to the coils from the CDI unit.

Have you done any mods to the dizzy, like changed the trigger disc or anything ?

nah i havnt done anything to the dizzy, as far as i know its standard fj20et dizzy, thats what i bought it as anyway.

its isnt anywhere near the spark plug leads or the wiring harness going to them, it is running with the rest of the power wires to the injectors etc, could this be a problem?

cheers,
blayne

I don't think the injector wires could interfere with the signal, but it may be worth a try.
Have you put the timing light on your car to confirm that the timing is out ? And it may also be woth pulling the dizzy out and removing the top plate to look for dirt or crap inside, that will screw the signal to the opical sensor.

i will try pulling the dizzy apart and cleaning what i can.
ive got a snap-on timing light and ive tested the fj with that.
it seems to be idling at around 15degrees advanced and as the revs increase it climbs to around 40degrees advanced.

is this right? the car is going to get tuned on monday so i guess it will get sorted out then but id rather give the tuner a better platform to tune from.

the engine wil not come onto boost or rev above about 3 grand, turbo is a big T04 though, what could it be?

cheers,
blayne

Most aftermarket ECU's struggle with the FJ dizzy with it's 360:4 trigger wheels.
The late model S12 dizzy's are a significant improvement.
I had some new 4:1 trigger wheels cut that fit inside the stock FJ dizzy. The ECU I was using at the time was much happier with that.

I eventually went to the electromotive 60 tooth wheel mounted behind the crank pulley, and threw the dizzy away.

Hey Tim, where did you get the electomotive sensor for the FJ, and was a much trouble to fit ?
And how does your ecu detect no1 TDC (sync)? Don't you need a cam trigger for that, or at least use the dizzy for no1 TDC signal (sync)?

I run an autronic SM4, which means I have changed the trigger disc to suit. I think that most aftermarket ecu's would work better with this trigger disc, rather than the stock unit.

hey tim,

do you think its neccessary to change the trigger disk?
the car is going to the dyno on monday so im not sure what to do now?

do you have any of the triiger disks you had cut left?

No!
Microtechs interpret the signal from Nissan optical 360 degree Cas's just fine and dont require any funky timing disks or mods.
I have Microtechs running on both my FJ20 et and my wifes Pulsar turbo ET which use the identical dizzy mounted CAS's.

M8, its going (in a fashion) leave it alone and just get it to your tuner.

L8tr
E

Is this a new install, or have you had the car running until one day it just decided not to run anymore ?

Guys, yes, if you can get the late model dizzy (s12), the aftermarket ECU's seem fine.
The wheels I had cut were for the early dizzy.
The elctromotive wheel requires a bit of fabrication to mount behind the crank pulley. it has a missing tooth to detect tdc. You will need to check with your ECU maker to see if it can use this type of signal
I run two coils in wasted spark config, and no dizzy at all.
I was getting a fair bit of scatter in the spark timing before I went crank trigger.

Ben runs the late model dizzy for a trigger, but 4 separate coils for the spark. He's left the late model winged rotor arm in the dizzy and found it removes all the scatter.

gday,

change of plans, car is going to the tuner on wedensday morning so we will see what happens with it.

i changed the plugs to bp7es and had the injectors flowed and cleaned.
i rewired the dizzy and made it separate from the main harness so there is no chance of interferance.

everything has been checked and double checked. got all new silicon vacuum lines aswell, so everything seems to be spot on.

i will be starting the car tommorow and let you all know how the changes i made affect it.

cheers
blayne

is there a difference between the fj20 turbo and non turbo distributors.

if so how do you tell the difference?

Nope
L8tr
E

There are heaps of differences in the electronics inside the early and late FJ20 dizzies. As Tim says, the later model ones are much more reliable, the earlier model ones are prone to playing up, especially when the engine and/or ambient temperature is hot. Both Tim and I found the 4 and 1 wheel fixes most triggering problems you get with aftermarket ECUs. Thanks Tim !

BTW, if you simply can't get your dizzy to work properly, it can be faulty. Under these circumstances I have found a good way to go is to put the guts of a late model dizzy into the FJ dizzy housing - try one from a SR18 engine (pulsar), which bolts right in, or some early 90's mitsubishis which have a 4 and 1 CAS, the guts of which also can be made to fit the FJ20 dizzy housing without too many problems.

Or just buy a new CAS from petroject or any other EFI parts suppliers.
About 160 bucks all in last time i bought one about 6 months ago.
They are still used in a range of current Nissan vehicles.
Cant see the point in funky dizzy guts alterations when the factory sees fit to use the exact same CAS to this day.
Takes all of about 20 minutes from bonnet up to bonnet down to install.
L8tr
E

Hey E,

Can you give a bit more of an explanation on the petroject CAS, do you remove dissy from motor to install it & do you have a part no. for it.

Regards
Brett

Hi M8
Ummmmm I dont have a number but its the same CAS as a Pulsar Turbo ET (e15et) and quite a few other Nissans (Pathfinder V6 is another I think)
Petroject will know what your after if you mention the E15et CAS.
There are 2 types for the e15et, one that screws in from inside the dizzy and the other more common type that is screwed into the dizzy from underneath the base of the dizzy.
You need the kind that screws in from underneath the dizzy. Electrically the same but just attach into the dizzy differently as mentioned above.

Just remove the dizzy (note its position and where the rotor is pointing after you pull it and clamp the dizzy gently in a vice with soft jaws.
Remove the rotor button.
Put some grinding paste onto a good, fresh Phillips screwdriver and remove the screw from down inside the dizzy shaft. You'll have to stop the shaft from spinning so gently clamp the drive gear for this.
The grinding paste is to stop the Phillips screwdriver from slipping and graunching out the head of the screw. That screw is usually quite tight and if you bugger that Phillips screw head you'll have a real devil of a time removing it at all if you chew it out and that will ruin your day big time.

The rest comes apart easily and is pretty self explainatory altho the rotor button shaft bit may require a little persuasion to come off.
Just note the order and orientation of the drive washer and any shims above or below the timing disk and which way is actually UP on the timing disk. If ur not confident, mark the bits with a texta to make sure.
The disk can be replaced upside down and all will go to **** when you try to run it.

Once all the rotating clobber is out, turn the dizzy body upside down, pull the wiring harness plug out and remove the three screws that retain the CAS and the CAS will fall out.

After you re-install the CAS and the other bits, make very certain that the timing disk is not touching the CAS itself.
Just rotate the shaft with your ear right up against the dizzy so you can hear it.
There is bugger all clearance between the "electric eyes" of the CAS and the disk itself and I have had a disk that was scrubbing on the CAS which makes fine metal shavings and can clog the timing disk slots and electric eyes of the CAS and cause misfiring and timing scattering.
If this is the case, you can either shim the timing disk up or down or carefully file the threaded inserts equally in the CAS to lower it in the body of the dizzy.

Voila. Assuming no clearance issues with the timing disk then the whole job including R & R'ing the dizzy will take you about 20 minutes.

Happy Cas'ing
L8tr
E

Great to hear the latest CAS from E15/etc still fit. However some aftermarket ECUs will just not read the 360 slot chopper wheels as well as the factory ECU. If your problem persists after replacing the CAS with a new one, and all your wiring is correct and well shielded, you must assume that the chopper wheel is a potential culprit and thus just get a 4 and 1 wheel for FJ20 from Ray Hall turbocharging and stick it in. Autronics appear to have more problems than most ECUs when time comes to reading the 360 slot wheels, so the discs are available from them off the shelf.

good luck all