anyone know what would cause the timing to be moving about when checking with a strobe? Electric/sensor fault or possibly the belt on slightly wrong as it was just recently changed. Not my car btw.

Firstly, where are you taking the timing gun trigger from? The black wire loop by the PTU harness is not a good point for many guns.

Could be a number of things. As Andrew mentions, pick up point for timing light, could be beginnings of a faulty CAS, could be an under tensioned timing belt.

 

What's the idle like? Stable or fluctuating?

The idle seemed stable although a little high.

 

The gun I use is a one that JeffTT recommended on here many years back and its always worked perfectly. I use it with the pickup open and on top of coil pack 1

what year car ? For cars with 16 bit ECU's this is normal and you need to lock the timing with conzult, before you can accurately measure it.

Thanks all,

It's a 92 car so will have the older ecu.

 

Lemon, out of interest, how do you lock the timing in conzult?

anyone know what would cause the timing to be moving about when checking with a strobe? Electric/sensor fault or possibly the belt on slightly wrong as it was just recently changed. Not my car btw.

 

Ok, so to claify, whilst viewing the timing via the timing light you see the timing jump about ? so there are very little things to cause this,

 

1 ) The hard idle switch on the tps, if this is a bad connection at the plug, or is marginally positioned it may click on/off and this will raise the timing ( thinks throttle is been opened )and reduce again if the setting or connection is intermittent. cleaning the connector and / or resetting the tps will cure this, you can view the tps open / close signal on ConZult to see if it is pulsing on /off when not using the throttle and that is the problem

 

2) The cas unit optical unit is failing, this will often also cause retarded ignition / poor power when accelerating, hold the throttle at around 1500 rpm whilst watching the timing light it should be stable, now rev up with a quick blip on the throttle, the timing should advance, if its sporadic or retards the cas unit is at fault.

 

A few tests should make it clear where the fault lies.

 

Also, I would like to know how to lock the ignition on 16 bit ecu via the ConZult.....interested.

 

Jeff

Ok, so to claify, whilst viewing the timing via the timing light you see the timing jump about ?

 

Yes mate. And thanks for the other info. I suspect the failing CAS to be honest, but I'll double check the hard idle switch too.

> Also, I would like to know how to lock the ignition on 16 bit ecu via the ConZult.....interested.

 

Timing should be locked as soon as you change the timing in the "MAIN SIGNALS" window

Best is change timing by a couple of degrees and try to make the engine run smooth if possible, to avoid stalling