can anyone tell me what part controls the start up revs on a 16v ive asked this before, but my 16v revs to around 2k on initial start up, it then settles to a normal idle dont preach to me about basic set up etc, ive had this car 11years and its always done, it still p1sses me off and i want to sort it....over the years its had nearly every part of the inj swaped/replaced
I have had 2 valvers. My previous one did exactly as you describe. My current one doesn't. As you say, I used the same basic setup on both cars and again on the previous car changed many parts to try and cure the reving, without success. At first I thought it might be the ISV circuits but tested all the sensors to no avail. It has just occured to me that I never tried starting the car from cold with the red wire disconnected - thus disabling the ISV - to see if it still reved up. Have you tried that? Over time I decided that a possibility was that fuel pressure was dropping over night allowing a big surge of fuel due to no control pressure but where would the air come from with a closed throttle? As I struggled with this problem myself without a cure I too would like to know the answer to this question. Edited by: stevef
Mine does the opposite fires up but really struggles to run at about 300 rpm, then by magic after 10-20 secs it revs normal! - only when cold - perfect even after 5 mins of driving! It has started normally after fiddlting with the sensors side of the wiring, so i am guessing (like i said in the PM, that i may have a dodgy wire inside the black sheath)
It's got to be the ISV opening right up at initial start up, my old car used to do it too,can't see the problem with it personally, well other than the death rattle from the crank as it fires up Nothing else it can be. Going to be controlled by the ISV box,surely. Mine's surging when it's cold at the moment - bounces from 1000-1500 until it's warmed up, I'm going to smash it with a hammer if it keeps messing about Need to have a good look at it to sort it,fixed the thermo time switch wiring thinking that would help it,but no Either got an airleak or it's something to do with the ISV/box/senders etc I think[:^(] Edited by: GVK
yeah its just the death rattle that annoys me thing is ive tried several new/used isv's and another isv controler im sure it should rev a little..say 1300-1400 but not as high as mine does
As I say my old 'vvo' 16v used to rev to 2k on start up, I just used to arm the ancient fuel only immobilliser so it wouldn't start,crank it over to get oil pressure then disarm it and start it up so it didn't do the crank rattle
Well I won`t preach about setting it up, but while I was f**king around with mine last year it didn`t rev to start with, then did, then didn`t (if that makes sense? ), I seem to instigate the fault and then tune it out again somehow? Has to be the ISV opening/sucking a load of air in as Gary says, but why?..
kev...the instant it fires it shoots round to 2000 revs or more and then gently settles to idle..id say 10sec keith/gvk it could well be the isv is open too much, but something other than the isv or controller is causing it
Yep same as mine, but the opposite if you see! I have tried several isv's all the same! Ok, i juts disconnected the red/black (ISV) sensor lead - It fired up but idled around 200rpm with the battery light on (alt not getting turned enough) Then re-connected and disconnected the blue/white (ecu/ign-module)and it fired up fine and idl;ed a lttle lower than normal - around 900rpm, but was steady even after 5 re-starts. so maybe try that and see if it works for you? I will leave it over night disconnected and see how it goes in the morning btw what does the ecu/ign module control, i thought it was the cold start but the thermotime switch does that doesn't it?
One of the temp sensors on the head is for the isv controller which compensates for cold starting (CSI) by opening the ISV more to get the car going. Could be a duff sender?
yep,worth swapping a couple over,prolly already tried that though have you tried another cold start valve and thermotime switch? neil.
may be worth checking electrical connection on the wur...MAd a big diff on my 8v syncro when i built that.
right then, blue/white sensor disconnected, started up the same (crap)! Drove to work and it made no difference being disconnected - what does this mean? Don't think this will help you steve, sorry!
Mine also revs high when started, but drops to 1kRPM. After that it starts to get lower and lower, and some times it dies. For the first 20secs maybe, if I press the pedal, the RPM will drop for 1sec, and raise after that. So if I'm not carefull the car will die... After that, all great!
Gary - Mine used to do that and it was either air leaks, hole in the exhaust or badly adjusted warm up regulator that caused it. Go for air leaks first and have a look at that grey overrun cut off thingy as that's where most of my problems were. If you hook up a fuel pressure gauge you can watch the control pressure altering from a cold start and listen to the revs surging to see if it's a WUR problem but unlikely if it starts and runs alright generally. Also worth checking wiring to those three temp senders and WUR in my experience. Pigbladder - it's got to be the ISV and WUR hasn't it that sets the revs too high from a cold start? Mine flicks up to about 1500rpm and then drops over a few seconds which I think is the correct behaviour?
stu....over the years its had loads of isv's and wur's none of affected it at all i had that prob last year..remeber?? i tweaked the fuel pressure all over the place and nothing changed seems to rev harder on these cooler mornings
Just a thought but don't the saucer shaped thing on the airbox increase the fuel on cold starts? maybe it's that!
