Inconsistent "mark" when using timing light

[fr335tyl3r]

Hey all,

Need some advice on a problem that I have with the car at the moment. The MPI conversion is pretty much done and dusted but we are having a problem now we are trying to crank over the engine and get the base timing setup (basically the last thing that needs to be sorted).

I am running an optical distributor from a sonata (the same era that the mpi manifolds get pulled from), which has a 4+1 disc in it hooked up to my e6x ecu. The ignition is running wasted spark with 2 twin coilpacks.

We have hooked everything up, got a timing light on the first plug and my mechanic is watching the light while I crank the engine over. The e6x has the injectors off so that it won't try and actually kick over, and timing is locked at 10 degrees so we can setup the distributor angle.

The problem is such that as the engine cranks over the mark rotates around (rather than the expected where every spark lands the timing light mark in the same location). We describe this as "sporadic spark angle" as there is no real consistency with the angle while its cranking over.

Another diagnostic is that the engine speed RPM guage on the e6x is showing a fairly erratic rpm speed when it cranks over as well, jumping from 125rpm to 1888rpm and everywhere in between (those are just 2 values i can remember)...most of the time it bounces around 150-350rpm though.

To me the above 2 problems would indicate a problem with the grounding of the shielding for the trigger signals. To begin with the ground for the shield was connected at the sensor end, which would cause problems...this has since been cut so there is no longer a connection, but the problem persists. My mechanic feels that the problem is not with the shielding but is with the dizzy itself (he thinks that 4+1 will not work and I should be running 4+2).

Am I correct in thinking that 4+1 is capable of working? If so, any ideas on what the problem is and how I could diagnose it?

Another possible cause was raised when I was talking to one of the other starion guys who brought up it could be that the trigger/home signals are around the wrong way (ie, ecu is recieving 4 home signals and 1 trigger per revolution). Could this cause the problem?

Any ideas would be great...really want it running.

[mrb1]

Are all the outer slots on the Sonata distributor the same length? If not you may have to change the trigger edge.

[fr335tyl3r]

I haven't measured them accurately with a ruler or anything but from looking at them it seems like they are all the same length.

I think the trigger is currently set to falling edge, should I try changing to rising edge?

If someone knows a bit about haltech setups, I have the map available so you can have a look at the setup. I know a bit but evidently not enough about trigger setup

[Starion VR4]

Ok,yr in luck.. maybe. Just changed my sons Staz to wolf3D using the optical dissy & VR4 coils, wasted spark units, had a similar problem, the input signals were correct but the ECU couldn't enterperte them, it was just the settings in the software, I am not fimilar with haltech but I can give U our setup of the Wolf. Also U need to use the rising edge on both signal & reference. Wolf also require 1/4W 1K pull-up resisters in the signal out, the dissy works on both 12V & 5V so which ever voltage u use is ok, my engine i used 12V, on my sons I used 5V.
:beer

[jakobsladderz]

you may need pullup resistors or to enable a pullup device within the configuration software. the Sonata style distributor works as a switch to ground (quite a common setup with optical and hall effect sensors), so you need the ECU to have a resistor to 5V so that when the switch is off you get 5V, when it's on you get 0V.
You can check this side of it with a multimeter on volts setting. Whilst turning the distributor (or slowly turning the engine over with a ratchet on the crank pulley bolt) you should be able to measure the volage on the input to the ECU going between roughly 0V and 5V. if it doesn't, that could be the problem.. If it's expecting a hall effect signal and there's no pullup resistor it could be picking up heaps of noise , which would show up as random RPM levels and ignition triggers..
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Those resistors are probably in the ECU, they may need to be switched on..

[fr335tyl3r]

Pullup resistors eh? I might check with the guys at haltech to see what they think of the situation and whether they recommend putting any pullup resistors into the circuit.

Any other ideas incase what has already been said doesn't work?

[pajeroturbo]

hall effect. trigger and home edge is rising. trigger angle will be 50 if you are using your dizzy and not waste spark. spark edge will be falling and charge time is 4.0ms.

[merlin]

I can confirm that you need pull-up resistors
and
set the trigger software to rising edge.

The resistors can easily be as low as 220 ohms, if you suspect noise getting into the trigger circuit. 470 ohm is a good choice regardless.

[mrb1]

I can confirm that you need pull-up resistors
and
set the trigger software to rising edge.

The resistors can easily be as low as 220 ohms, if you suspect noise getting into the trigger circuit. 470 ohm is a good choice regardless.

Haltech's normally have "pull up" resistors built in. Jeff will have to check with Haltech.