VR Oil Pump and Timing Chain.

[vlad01]

I normally do replace the bolt, you can get them pretty cheap from ZZP but the shipping from the US isn't viable for a small order like that. Going by the feel of the bolt when it tightens, I don't think its torque to yield, I was replacing them as a precaution but I think it should be fine. The workshop manual mentions nothing about replacing them, so it should be fine. ZZP also list the torque + angle specs on their site for the bolts listed there which is a bit more accurate and consistent than just torque alone.


Yes, toss that magnet in the bin. They are known to occasionally come apart and wreak havoc in there, more so in a performance application/use. With an 808 ECU it's not needed anyway, the manual VR didn't run them either, so it was only the auto VR that used them with the 424 PCM, and of course the later ecotec V6 since they were sequential injection. The Buick at least in Aus didn't run sequential, VR auto ran a bank injection mode which was pretty useless, nothing of real world benefit over the normal batch injection.

[Stag76]

All back together and running a lot quieter than before.
Thanks again for all your help.

[vlad01]

Nice one!

[Stag76]

I'm changing the Oil Pressure Switch for an after-market one that communicates with a
combination Gauge/Light.
I'm runing the fuel pump via a relay switched by ECU Pin A1, Green/White, with a permanent
switch ground.
Will the engine run without this signal, or will I have to bridge some pins on the plug?

[immortality]

The fuel pump is wired through the oil pressure switch via the 2 way relay. The ECU only primes the fuel pump when you first turn the ignition on, then when the engine turns over and builds enough oil pressure it powers the fuel pump. This is a safety feature, if the engine stops than the fuel pump also stops which is desirable in the case of a accident. I'd suggest using a brass T piece so you can wire in your external oil pressure gauge as well as using the factory oil pressure switch.

[vlad01]

Pretty sure its only for limp mode for when the ECU is in limp and can't switch the fuel pump, like an analogue fail safe sort of deal. So yes, you can do away with the factory switch, limp mode is practically useless anyway due to how bad it runs.

[immortality]

Pretty sure its only for limp mode for when the ECU is in limp and can't switch the fuel pump, like an analogue fail safe sort of deal. So yes, you can do away with the factory switch, limp mode is practically useless anyway due to how bad it runs.

Simple test, unplug the oil pressure switch and start the engine and see if it will continue to run.

[vlad01]

It does, I've run a mechanical oil gauge to check the pressure and nothing else connected. Ran like normal. The switch is also why limp mode won't fire straight away for some time after cranking continuously, takes time for the pressure to build enough to switch at cranking speed, usually anywhere from 5 sec to a good half min depending how long since the engine last ran.