Thoughts on driving ECU programmed for VVT with non-VVT engine V8 WRX?

[Guest]

Hi,

I had an engine transplant done, on a 2003 NZ New V8 WRX the new engine that I put in was a early 2003 one which did not have AVSC (Variable Valve Timing), however the ECU that came with it will not work as the alarm is not programmed to work with it, I am getting this fixed at Subaru next week, but am driving the car at the moment with the later 2003 ECU which I have had scanned and is telling me it is not receiving the cam signals. Car seems to drive nice enough, but I plan to take it down to bluff on the weekend from Dunedin,

My question will I be doing damage to it driving it, I dont plan to push it, but obviously will be getting driven a bit harder than around town for overtaking and what not.

The ECU ive been told will go into default mode as it is not getting the signals, but unsure if that means it will be running a higher fuel mix, or not.

Also what are your thoughts on what I should do with the guy I brought the engine off, he said it was an 2004 engine in the Trademe auction and prior emails, if it had been an 2004 I would not have had any off these problems as my ECU would have been fine to run with it, as Subaru made AVSC standard on all Subarus in late 2003 for emission reasons. As its costing me close to an extra $400 to sort the ECU issue

Cheers and thanks for your help.

[Wiretap]

You've got both ECUs don't you?

Where are you in Auckland? I can modify the tune on the AVCS-equipped ECU for you to drive a non-AVCS engine

[Guest]

Yep got both, bugger im in Dunedin, I got told by the guys at Turbo777 in Dunedin on Princes Street that its a real challenge to change the ECU as it would have to have all the fuel ignition programming tuned and that they had no idea how to turn off signal telling it the cams were missing, cheers

[Wiretap]

What you can do then, since they're all nupties down there. is either find someone with an OpenPort or buy one from www.tactrix.com . Use that to pull the ROM image from both ECUs and send them to me. There may be someone down your way who can help you but I'm afraid I don't know who.

[Stoffa]

it would probably throw codes for the AVCS (VVT) if there was no signal going to the solenoids.

but it would probably hold the timing at the minium setting as a safety feature, so if I understand how the system correctly, in my opinion it shouldn't cause damage, you'd just be down on power.

[MercuryFree]

Iirc, the avcs uses a different table(s?) in the Ecu when activated, so it's probably not going to do any damage. It's probably making less power as a result though

Edit: OK, what he said ^^^ essentially

[Wiretap]

 MercuryFree said:

Iirc, the avcs uses a different table(s?) in the Ecu when activated, so it's probably not going to do any damage. It's probably making less power as a result though

Edit: OK, what he said ^^^ essentially

Nope, The AVCS does not cause a table change. AVLS does, but on non-AVLS engines the only thing that causes a table switch is if you have a tonne of knock.

Unless it has thrown a CEL, the ECU is ignoring the fact there is no AVCS. Because you didn't have exhaust-AVCS this should be okay, but you will as they said be down on power.

I personally would still recommend fixing it.

Worth noting that I can do this another way but you'd need to send me both ECUs which would mean your car was out of action for 1-2wks.

[Stoffa]

 Wiretap']

[quote name='MercuryFree said:

Iirc, the avcs uses a different table(s?) in the Ecu when activated, so it's probably not going to do any damage. It's probably making less power as a result though

Edit: OK, what he said ^^^ essentially

/quote]

Nope, The AVCS does not cause a table change. AVLS does, but on non-AVLS engines the only thing that causes a table switch is if you have a tonne of knock.

Unless it has thrown a CEL, the ECU is ignoring the fact there is no AVCS. Because you didn't have exhaust-AVCS this should be okay, but you will as they said be down on power.

I personally would still recommend fixing it.

+100000 would just turn a nice car into a lemon

[mattapo]

mmmm, the whole alarm thing is just a pin in different position iirc, if you swap the wires round you should be good to go with the correct ecu