Ls1 conversion wiring help needed

[Jayme]

sorry mate.. not a clue. never used a circuit like that, it could be a problem with the value of capacitor you are using? all I can think of is to put a scope on it and see what the waveform looks like.

[vp304]

dammm hopefully vl400 can help me out

[delcowizzid]

i would set the 4 top values in that list to the correct calculated values i think they are all inputs if they dont all suit each other it could do all sorts of weird shit if its confused as hell and nothing matching.

[Holden202T]

im just wondering, you say the signal goes from the gearbox sensor to the cluster then from there into the converter box then to the ecm ..... are you referring to the cluster output goes to the converter box ?

if that is the case im wondering if it would work better with the speed sensor getting Tee'd into 1. cluster and 2. into the converter box without going into the cluster ..... so effectively its getting a direct signal.

I know the clusters divide the signal by 5 and spit out that to the ecm maybe that part of it is causing the issues and the raw signal from the speedo sensor might be a better option.

I am no electronic expert though so I might be way off the mark too ..... I have only ever had two non standard speedo setups, 1. T700 in a Torana, speedo signal went to a VDO electronic speedo and calibrated to suit, but it took the direct signal with no mods, and the 2. is same T700 sensor on a trimatic which feeds straight into the ecm with no other connections.

[vp304]

Yeh I thought maybe the cluster is causing the signal to go a little funny
If my El chepo obd2 shows the vehicle speed I can prob chop the signal and get it before it goes to the cluster and send it straight to the converter box.

[VL400]

Def try going from the sender to the PCM direct, along with checking the settings such as 17 pulses per rev if that is used for the input.

The capacitor trick leaves the wave as a square shape, it just goes negative. The PCM does not care about the shape just that it has a zero crossing, or signal that goes high (12V) to low (some negative volts) or low to high passing through zero volts along the way. If your signal has very short duration high levels (you would need a scope or multimeter that can measure duty cycle to know this) then it does not go very far negative. This might be your problem as the divide by 5 circuit in the dash will make the signal spend a fair bit of time at 0 volts.

Although this trick has worked for me in the past on a few conversions, maybe it was just lucky?

[vp304]

Thanks Vl 400 I will skip the signal going to the speedo and send it straight to the converter box from the side of the gearbox and let you's know how I go

[vp304]

Maybe what your saying sounds right vl400 as I knoticed down low the ls1 ecu speedo (in mates efi live) shows 0 kph till you get till about 40 50kph on the dash cluster

[vp304]

Ok tapped of the signal wire before it goes to cluster.
Fired up the car
at 30kph on the cluster
ls1 ecu is seeing 200kph lol

May get my mate to adjust the ppk value on the ls1 ecu and see how i go

Vl400 you think the vehicle pulses per revolution should be changed from 17 ?

[Holden202T]

yeah that's because the cluster divides the signal by 5

if you divide 200 / 5 that's 40 ... so pretty close to what your seeing! 6250 is the stock setting for that sensor without going to the dash (assuming 3.08 diff and 215/65/15 tyre)