Started by stuclark · 27 Oct 2009 · 11 posts · 1,425 views
Hi Mark,
I go past Guildford all the time, so I'll drop you an email next time I'm going to be in the area.
My IAC valve is just a bit sticky, but is working ok other than that. It's been diagnosed by slight initial hunting when returning to idle; or sometimes mis-setting the idle speed. A "reboot" always cures the problem as it resets the valve position, so I don't think there's anything major there...
... but, taking that into account, it's still running rich most of the time...
Thanks for that, I think we're talking about the same bits of kit and connectors. What's "odd" is that the UK / Europe wiring diagram shows the existence of the "EFI diagnostic plug" but it plainly doesn't exist on my CSK in the same location (normal location) as on my friend's '93 model. (incidentally, the ECU on his, which I think is the same part no. as mine, IS able to read and reset the fault codes using the NAS code reader)
The reason for reading the codes on my part is / was mostly for interest only. I know I have a sticky idle valve, and had a faulty temperature sender (now changed) so merely wanted to see if these had flagged up in the ECU and reset the faults if they had. Having done similar things on the '93 model, it made a significant difference to the vehicle's performance, so I hoped the same might be true of mine.
The only outstanding "fault" I have is that the car is still running somewhat rich. However, there's still a few things I can check (plugs, disti, rotor arm etc).
Mark, that's what I thought...
The white (5 pin) connector is indeed there, plugged into the male / female equivalent, with one wire (1 pin) shorted between plug and socket. (no other connectors on the trailing connector)
I've been told (and indeed proved on a '93 model) that this connector is the "serial link" and can be used to reset / clear fault codes on the ECU. It's identical to the one fitted to a friend's '93, except that his has 2 pins shorted on the trailing end of the plug.
The diagnostic port I'm referring to isn't this one - it's another 4 pin, black, rectangular connector which on the '93 model (and according to the '90 wiring diagram) comes off the same bit of ECU loom under the drivers seat.
I've a feeling that as the RRC wasn't being sold in the US in 1990, the port isn't on the vehicle even though the wiring diagram says it should be. (there was an optional "customer fault code reader" available for US customers which plugs into this port and allows the lamen to read the ECU fault codes. There's a corresponding clip on the underseat bodywork on a '93 model to accommodate it's fixing)
Edit: I'll get / take photos of the connectors I'm referring to if it helps to describe what I'm on about.
Yep, ABS stuff is under the passenger seat.
The connector I'm talking about should definitely be part of the engine ECU loom, next to the tune resistor (which *IS* in the correct place under the drivers seat)
... I'm guessing it just doesn't exist on the CSK :(
That's the full Rovacom connector.
Some / all RRs from 1990 onwards(especially US market ones) had a secondary connector "for the owner" to be able to check the codes. From the wiring diagrams in the workshop manual, it seems the CSK should also have this connector, but I can't find it in the correct place on the wiring loom on my car :(
...so who here has played the diagnostics game with their engine ECU?
On "other" RRs of the same age, there's a diagnostic port (socket) built into the ECU loom, which you can plug a gizmo into and read (and subsequently reset) the fault codes out of your ECU. However, on my CSK, I haven't been able to find the diagnostic port - the ECU loom doesn't look anything like the same under the seat.
Does anyone know if this port even exists on the CSK? The chap who I've borrowed the diagnostic reader from isn't sure...
