Quote:
Originally Posted by john.wigley
Hi Adam, Is this a recent phenomenon? If so, might it not be a fault as such, but due to the high ambient temperatures coupled with the load or drag on the transmission when you engage D or R? Most of the automatics that we have owned over the last 30 years have exhibited similar behaviour to a greater or lesser extent.
Regards, John.
|
This has given me an idea for the RB John,
There is always a little drag when the shifter moves from P/N to D/R/2/1 just due to the fluid flywheel never providing zero torque - this manifests itself as creep, which all autos do and is actually quite useful in traffic. When this happens there is of course a slight drop in engine speed because there is no computer (ECU or whatever) to correct it - the RB is entirely an analogue machine.
Now here is my idea to counteract this: the anti-dieseling solenoid isn't really needed so I could reverse its action so it actuates when the shifter is in D/R/2/1, but is isolated in P/N. If I adjusted the tick-over so it was set at 850RPM with the anti-dieseling valve closed, then took a feed from the starter immobiliser (open only in P/N) to a 5 pin relay wired as NC between pins 30 and 87a to the anti-dieseling solenoid, then it would only open in D/R/2/1 - raising the engine speed by a few hundred RPM in those gears only.
What do you think? Would this work? I'll see if there are any comments telling my it won't work - and if not perhaps I'll experiment on the RB with the B21a motor fitted before I transplant the B230 engine.
:-)
PS. I've just spotted a flaw in my logic about using the starter immobiliser - I don't think it wouldn't be energised unless one was operating the starter (I have not checked the wiring diagram, but I think it would be wired in series with the starter switch and solenoid). The problem isn't insurmountable - I could fit a microswitch somewhere to replicate the action of the starter immobiliser.