Hi all, a Corrado 16V which I look after is experiencing some major idling problems, it ticks over very erratically ranging from about 500rpm up to around 900, but it sounds like its going to stall. Its experienced fuel pump failure, and was driven for a while running pretty lean (now fixed), and has more recently suffered some overheating problems (also now fixed with new water pump). Mechanical injection is a bit of a mystery to me, so can any one advise me as to what might be causing the idle problem? Many thanks, Jaundice
There's an enrichment gizmo on the side of the metering head - try unplugging it and see what it does. If it's a 2.0 16v it's KE Jet though, and should be possible to scan it for fault codes I think. VAGCOM cables under the gear lever gaiter, if you want to check first.
I had it on vag com a while ago and couldn't get any response from anything off it, not even the ABS. Sorry to sound thick, what does the enrichment thing look like?
It's an electrical multiplug on the side of the metering head. Inner wing side, IIRC, although I haven't looked at one recently.
While I'm asking about this engine, can anyone tell me at what temperature the fan should come on, and if it should have 2 speeds or just one. It currently only runs at one speed and doesn't come on until it gets to 110C. TIA
Yep its a 3 pin fan, its not coming on at the lower speed setting, any clues as to the possible cause RJ?
if it works on high then it could be the sensor, the fan or the low speed wiring. to start with disconnect the 3 pin plug at the sensor and bridge the red wire to the red/white, then the red/black. fan should run on slow and fast. if it does, its the sensor. if not, jump the fan pins direct from the battery, if it works its the wiring, if not its the fan. oh actually look at the sensor too, some of the 2 speed ones are the same shape as 3 speed but with a pin missing
right then, the fan issue is the sensor (thanks RJ ) it will be changed as soon as i can get one :-) Thanks also to Mike, unplugging the enrichment thingy caused the idle to go up to 1100RPM, plugging it back in bought the revs back down to about 1000, and ticking over beautifully :-) What does that mean? I dunno if it went back to being crap when she drove it home, i will no doubt find out later.
Well the idle went back to being rough again next time she drove it, what does this mean? Does she need a new metering head ?
With regards to talking to the 9A ECU using VAG-COM / VCDS, I've just worked out exactly why a USB / VAG-COM adapter I have doesn't work, and easily modified it so that it does work. It's probably the reason why so many VAG-COM adapters are unreliable with the 9A ECU. If you want, you could buy the same adapter I have off eBay, wang it over to me, and I could change the resistor for you. Or tell you which to change if you want to do it. It's useful being able to use VAG-COM with the engine ECU I think, as it's a convenient way to see the status of all ECU inputs, and also I believe that entering Basic Settings - 04 puts the ECU into diagnostic mode (specifically, turns off digital idle control) which is what you're supposed to do to set up ignition timing. I'm sat in the wife's Corrado right now having just modified it and it has gone from almost being impossible to connect (and only working for a few seconds when it actually does) to just working perfectly. For the sake of interest, here's a fault code it has just given me:
trev do the measuring blocks work in vag com? if so you can check the value for the ecu temp sensor and tps if it has one, lambda may be worth a look too
Aye - you can do "Basic Settings" which is the equivalent of 1551 setting "04" and also "measurement blocks" which is the 1551 "08" function. VCDS comes with a label file 8A0-907-404.lbl which tells you about the nine readings you see in Basic Settings, but when you go into Measurement Blocks you see another set of information, and I don't have the labels for those at the moment. In Basic Settings you see the coolant ADC reading (decreases with temperature) and the throttle switches are represented by a couple of bits in one of the values. Today's plan is to work though b3_25_cis.pdf and do all of the tests it describes, because with VCDS you can do all of the 1551 functions it calls for. Will take screenshots and stuff - actually I'll post up a Fred about it.
Ok I finally got round to changing the fan switch tonight and the fan is fine now, it comes on at both speeds as it should now, but it still idles like a sack of crap. Unplugging the enrichment thingy makes the idle jump to 1500rpm then when you plug it in, the revs drop to about 1100 but stay steady. Any ideas how to fix it? Can I replace the enrichment thingy or is it new metering head?
