It could be the WUR, what's important for good cold running is the pressure difference between hot and cold. If the cold mixture was marginal on the weak side then messing with the WUR will bugger the cold running. You need a gauge to test the WUR prssure difference. What you need is at least 2 bar difference between cold and hot running. Ideally the control pressure should be about 1.5 bar cold and go up to 3.5 bar hot. That way if the mixture is correct hot then the cold running mixture should be about right. Does that make sense?
I see good to know, i never new that!, some good stuff here, also i noticed that if the injectors are tiered (in my case) everything was set up fine, or so i thought, but it was all set up to compensate for the injectors, if you get me, once the good injectors were in the C0 originally set at 2% was suddenly at 7%. Also all kjet's are marginally different, so to set the wur up spot on you need somewhere like stealth to hook up on the machine to see what settings work best for that particular car! I got lucky doing mine i think although i still have not had it RR'd though
i can easily set the hot pressure to be right, and confirm its good enough by using the wideband tester trouble is ...all 3 of my wur give differant cold readings , none appear to be correct kev.. the kangerooing is just like a carb car when the choke is pushed in...i very much feel its too weak
have you tested the pressures from cold? ie. they rise steadily? indicating the wur is healthy. Like I said you will have to adjust each wur accordingly. You really need to know if they work as in rise from cold to warm as setting the warm is no good if the wur is fecked. On another note pigbladder, what is this wideband tester you're referring to??? Is it one of them things that go in the exhaust?? How much do they cost?? I might invest in one. Also like kev said, disconnect things one at a time to see if it cures it. But I wouldn't do anything until you know the wur works from the pressure gauge.
all 3 wur start low and rise steadily...all 3 of them start at differant pressures, funnily enough most of them seem to be too low pressure, so they should be overly rich?? i use a innovate lm-1 that i got from ebay.com , its got a widband probe which looks just like a regular o2 sensor..you can mount em in your downpipe or use a tailpipe attachment...you get a digital display that you can watch while driving , or press a button and record graphs n stuff
they should start off between 1 and 1.4bar when the air temperature is at 10 degrees. and rise over a few minutes steadily up to 3.45/3.75 bar at fully warm
there's 14psi in a bar!! so between 14 and about 19 at cold. you need 0-100 psi gauges ideally! to check the warm up process!!
just re-read. I thought your gauges were 10-20psi. That may be your problem?? the one that is at 10psi to begin with??
yeah thats what im thinking...ive put yet another one on, 16 psi cold, but 40 odd warm?? ive tweaked it to 48 warm now and will check it in the morning thing is 10 psi should be uber rich...black smoke and chugging etc
according to who?? tweak it to 48psi at warm and then test in the morning. have you got 5 bar system pressure??? if all is well then use your wideband thingy to tweak the mixture. then you can rule out the wur and fuel pressures. By the way the after 10mins of turning engine off the control pressure should not drop below 27psi, further 10mins ghouldn't drop below 23psi
erm according to ben watson fuel inj book.....16 psi at 50 deg f (+- 3 psi) and lower pressure means richer doesnt it? i got 76 system pressure...book says 68-78 pressure stays good after switch off...its down to 0 next morning and primes to 30psi
50deg f is 10 deg c. so more or less same figures i quoted 16(+-3) 13-19psi. doubt 10psi would make black smoke though. system pressure looks strong too!! Mine was 74 if i remeber correctly
Just for you information when mine was running lean from cold (micture adjustment fault) the revs would bounce up and down betwwen 700 and 1100 rpm until warm
all i can think of if another wur doesnt help , is maybe shiming the system pressure to sit at maybe 68 to see how it changes things i think the wur must be calibrated to that car at the factory...and if you use a working 2nd hand or new one its not calibrated finley enough...the 10 psi system pressure variation must allow for cold wur pressure to be 10psi out in worst case kev...so what fixed yours then?
have you tried disconnecting the cold start vale wiring?? although the valve may be working for first 10 seconds etc. is it really cold enough to actually need it?? what I'm saying is this could be making the mixture too rich if the sender for it is telling the csv to come on when it doesn't really need to.
i have tried it without in the past, all it did was make for hard starting in cold weather..to be fair yesterday it only squirted for a fraction anyway, the car starts on the button
What fixed mine, was new merc injectors and i set the wur, as per my FAQ's I then set the mixture to 2% as per usuall, and she has been perfect ever since apart form trouble starting, but i have been told the WUR mod does cause hard starts. It may be the TTS needs replacing about 30 fron VW i think, may try that when i get paid! Just for the hell of it i disconnected the 2 pin plug from diagraphm saucer thing this morning and it made no difference, maybe because it was not that cold??
maybe the saucer thing isn't working??? mine isn't connected on my mk1 16v conversion so I wouldn't know.
Don't know mate, i'll test it late, oops sorry getting of track here a bit! Any more news Pigbladder?
