SP3 dead stop, fans running, no link

[cycomick]

Hey Guys,

Finally got the scout up and running again today and starting tuning with the supercharger fitted...

Just thought i'd quickly ask your opinion on the cause of the following... Only had a chance to do some basic checks and have to go out now.

Idling in the driveway today, with the gauge screen running - the engine just shutdown and the link to the laptop disappeared - as though it was being switched off at the key.
Engine fan is now continously switched on with ignition on. Engine cranks as normal.

Only had time to perform a few checks:

Fuel pump energises as normal
Good Fuel Pressure
Sparking ok with spark tester fitted to lead
Laptop will no longer linking with ECU
FAN1 continously switched on with ignition on.

like I said have to go out now, have not checked injector pulse yet, but likely not working as not even a hint of a fire-up.

Fan ON and no link to ECU with laptop has me worried!

If anybody has some clues, id be very grateful...

[cycomick]

Ok so got home, did some more checking around... looks like a corrupt sram.

I pulled the ECM and fitted my original N03 SRAM and it linked with the laptop and fired immediatley.

What would have caused this? I see from some other posts that in can and does happen from time to time due to timing lights, bad wiring etc...

At the time, the car had been sitting in the hot sun for about 4 hours, the laptop was running off mains power... I went into one of the idle setting areas and bang... shutdown, corrupt sram.

One thing about my setup is the 1.8:1 gilmer drive alternator drive ratio drops the voltage at idle with fans running to 11.6 volts.
It's never been an issue in that it causes flat batteries or anything.... Once you're driving all is good. An auto-elec friend of my said this is quite normal with many vehicles, but could this harm the ECM?

Any ideas? I don't want this to happen on the side of Hume Highway on a 35 degree day!!!!

Cheers

[stormtrooper]

Not to sure about this but going by what you just said the problem I see is that atm there are a couple of variables, laptop power, battery power, alternator charge rate at idle, that all could be part of the problem on their own or even combined. I personally think you need to get the idle charge rate up if your going to allow the engine to idle for extended periods of time while tuning.

Were you watching the gauge screen? did anything look abnormal? were you recording?

I remember Derek said once that he has seen problems occur if the laptop is connected and suddenly shuts down.

[cycomick]

Not to sure about this but going by what you just said the problem I see is that atm there are a couple of variables, laptop power, battery power, alternator charge rate at idle, that all could be part of the problem on their own or even combined. I personally think you need to get the idle charge rate up if your going to allow the engine to idle for extended periods of time while tuning.

Were you watching the gauge screen? did anything look abnormal? were you recording?

I remember Derek said once that he has seen problems occur if the laptop is connected and suddenly shuts down.

Hey Stormtrooper.. Thanks for the reply.

Hmm, you raise some good points…. I know my laptop power was low at the time also… Charge light was blinking orange…. But I had it connected to mains (house) power charging at the time.

I remember that it was the exact moment I changed the idle speed variable with the RTLink button selected (dragging the bar upward) that the engine shutdown and ECM>PC connection was lost.

Perhaps low laptop power is the answer, (I hope!) as I have been running the gilmer gears at 1.8:1 for a while now with a VN commodore 85 amp alternator – and not had any issues.

Maybe the laptop battery has finally given up the ghost…. It’s a Derek sourced laptop and has been great, but I knew the old girl wasn’t going to last forever….

[stormtrooper]

Maybe the laptop battery has finally given up the ghost…. It’s a Derek sourced laptop and has been great, but I knew the old girl wasn’t going to last forever….

I had a similar, but not as bad, issue with my laptop as well. I ended up getting a new battery for it, the price was a killer but I had no other option at the time. I found with mine the power connector wasn't always connected either and if the laptop went into sleep mode then everything would just stop. I never had a corruption occur though so I suppose I should count myself lucky.

[DerekBell]

My guess would be the laptop was trying to read/write to the SRAM at the time of the crash, causing information to get lost, making the SRAM corrupt.

It could have been the laptop turning stuff off automatically to save power etc.

My issue stalled the motor, but as I wasn't editing at the time I didn't end up with a corruption, it was caused by the Laptop going into sleep mode..

You won't find too many issues with the idle power exept the ECU will adjust idle speed, fuel mixture etc for different voltages, as the voltage effects the way the injectors fire, and the quality of the spark given off by the ignition system.. As long as the voltage is constant at idle etc (not ranging) you won't have any issues, it is fairly common to have a voltage drop under idle in certain conditions anyway (headlights on etc), it is if it wavers etc it causes issues..

[cycomick]

Hey Derek, Stormtrooper...

Thanks very much guys, that could explain a few things. I def believe it was the laptop causing the issue as it was riiiiiiight when I was changing a value in real time....
I have since ordered a new laptop battery, eprom programmer and a UV chip eraser... Under $100.00 for the lot.... Delivered!

Cheers

Mick

[Hooter]

Hey Mick, I doubt that the battery killed the sram, although any thing is possible.
Its usually some sort of electrical spike.
Let us know what eprom burner you got and if it works out alright.
It may be worth while starting a post with some of these bargain tools that everyone needs
I bought (and recommend) a cheap $13 chinese UV erazor about a year ago to see how good it was and it is still working fine
It cost $35 including delivery on ebay.
I bought a Wilhelm programmer, but I cant get it to program srams
I got in touch with seller and he wasnt sure about it, and said try different speeds, but no go, whereas a friend has one and his is fine.

[BLOWN-VP]

i had a similar issue a while ago.v6 commodore all electrics in top condition.it was a very hot day when my sram corrupted.just wondering it it is something temperature related .cheers darren

[cycomick]

Hey Gents,

Have not had a chance to use the EPROM programmer or UV eraser yet.
Though It's linking up with the PC fine and seems like it will run on Win98 no probs.

Happy to do a write-up if I get them working properley. They were very cheap.

Don't know if i'll ever know what caused the SRAM issue.
It was a super hot day at the time, but like I said it was at the exact moment of making a parameter change in RT that it occured.
Whatever it was, i'm sure low laptop voltage, battery voltage and burning hot sun beating down on a convertible are less than ideal circumstances.

And to be honest, I'm still not overly confident having 11.6 volts at idle with everything running, despite 3 different auto elecs telling me it's normal.

Cheers

[stormtrooper]

And to be honest, I'm still not overly confident having 11.6 volts at idle with everything running, despite 3 different auto elecs telling me it's normal.

It isn't normal, not from what I have seen. I'd be trying to boost it to at least 12.5-13v at idle and 14.4 at about 1800 rpm.

[cycomick]

Sorting the charge rate issue at the moment with a VT 5.0 Bosch Alternator, they have a very high charge rate from low rpm.

I have the EPROM burner working great now with some help from a friend. It's a Willem PCB50.
There are specific settings in the software made for DS1230Y SRAM that allow you to electrically erase, read and write files quite easily.

I'll post a new topic with a full rundown of it's operation, cost etc in the coming days.

Cheers