VR HSV knock then momentary disconnect from tunerpro

[Mattyogi]

Hi all

I’ve been using tuner pro to try and track down a strange miss I’ve been having with my VR Senator.
For background it’s got a built 355 stroker and the tune tune is from chip torque.

When the car is cold it runs fine, no miss until everything is warmed up to operating temp.
When the miss happens it’s like a full cut out for a split second. idle then drops but comes back to normal with a blip of the throttle. It also disconnects from tuner pro momentarily when the miss happens. All the somsors also look like they drop out for that split second.
The knock retard flashes up a split second before the cut out / miss happens.

So far I’ve replaced the following as routine maintenance: coil, leads, plugs, 02 sensor.. I’ve also swapped in spare distributors, ignition modules, coolant temp sensors to rule those out.
None have made any difference for this issue.

Has anyone got ideas on what I should try next to fix this issue? Maybe knock sensor, Ecu or bad earths?

[antus]

I was going to say ignition rfi but youre across that. It sounds like the computer is crashing and restarting... i'd try replacing the ecm and check its power cables for damage/burns. Could also be the efi relay dropping out for a moment.

[VX L67 Getrag]

Could also try disconnect other modules to see if it changes thing as I know when ABS fails it causes lots of other things too.

[Charlescrown]

The VR ABS is not like the VT which yes brings down everything when it fails.

[delcowizzid]

Did you fit resistor spark plugs

[Mattyogi]

I’ll try out another Ecu and double the check relays etc. I’ll also have a crack at unplugging some of the other modules too.
I put in BPR6EF plugs and eagle 9mm leads. Also put in a Bosch MEC718 coil, dizzy is Bosch too.

I’ll post back up with results once I’ve had a chance to do some more testing.

[brindo]

Have you checked the flat connector on the ignition module? Sometimes they can have a terminal not sitting in the connector properly?

[Mattyogi]

I’ll check that out too ^^^

Is there any easy way I can check if it’s the knock sensor picking up mechanical noise one the engine is warm and oil has thinned out?

[Dylan]

Have you checked the flat connector on the ignition module? Sometimes they can have a terminal not sitting in the connector properly?

Yes they sure can, had that a few times

[antus]

Knock sensor? Well you wont loose everything including the data link like the pcm crashed/stopped or the aldl signal was drowned in noise. You'll see timing pulled and knock counts but the engine will run and the data will show it.