please only answer if you KNOW for sure, not what your mate at the pub says on a k jet 16v does the idle c/o ajustment have any effect over non idle engine speed driving? anyone got the proper test for the 5th inj enricment when cold... ive been through all the pressures and mixtures and still have it kangerooing when driving away from a cold start
I know you probably have tried this, but have you swapped over the ISV module? I had the same thing on mine and this was causing it! As for the C0 effect on non idle, i don't know, do you want the test for the 5th injector to see if it is working or not on cold starts? if so i got a pdf haynes manual I can send you (7mb) with the test for this!
The idle CO adjustment can make a difference to the normal runningas it sets the starting point for the control plunger movement. The simplest way to check the cold start injector is to pull it out the manifold and block the hole, then start the car and see how long it sprays for. On a cold engine it should spray anywhere from 1 - 8 seconds depending on the temperature. If the car still kangaroos after 8 seconds of running it's most likely not the thermo-time switch. Have you set up the airflow sensor plate hight correctly? Have you checked the vaccum valve down by the airbox?
ive tried several isv and controlers tried another spaceship thing near airbox plate is set correctly i understand the 5th inj should spray under cold acceleration? i wonder if it should be spraying as i put my foot down to move away on a cold start...need to test that function, it starts on the button
no it shouldnt be spraying when you put your foot down. it only sprays as golden said for the first 1-10 seconds then thats it finished with till you start from cold again. sounds like your vacuum flap in the airbox is out.
gareth, it looks right and stealth also checked it! id be willng to play arnd with it, but i dont know what affect lowering otr raising it would have ive got system pressure at 76 psi and warm wur is at 49 psi, the a/f ratio is spot on under acceleration ...the car seems happy to idle at almost any mixture, i might try setting a touch higher
is 76psi = 5bar?? my 16v mk1 is quite jumpy and I just gave up on it as it was causing more hassle than it was worth. I get about 29mpg on average and it's very fast. that'll do for me lol
Gareth much as I hate to disagree with you after you've just agreed with me, the cold start injector does indeed spray when the engine is cold under acceleration. The vacuum switch by the airbox runs the cold start injector for a fraction of second when it detects low manifold vacuum under acceleration. To test the vacuum switch put an ohm meter across the terminals on the vacuum unit and rev the engine, the meter should go from ifinity to some kind of resistance reading showing that its changing resistance with vacuum.
golden the vac switc checks out ok...do you recon if i give it a blip with the inj a jam jar ..should it spray when cold
Pigbladder, a bloke down the pub told me... I agree with Golden, if I remember correctly the 5th injector not only fires during cranking the starter (dependant on thermotime conditions) but also during acceleration when the engine is still in it's cold start/warmup cycle, ie. when the WUR is altering the control pressure during warmup for a few minutes or whatever it is. I could be wrong though as I've been thinking about carbs too much lately and forgot about k-jet...!
I totally agree here and you would notice if this wasn't working. I had some issues with cold starting and pulling away. Without the little vacum diaphram connected the car felt like it was being held back as if the mixture was out. I fixed the vacum pipe and it made the world of difference to cold driving.
the vacuum pipe on the WUR reduces the control pressure at low manifold vacuum (when you put your foot down). This happens hot or cold, it's a form of acceleration enrichment. This is why people suggest fitting the 16V WUR to early K Jet 8V's as it has the same effect as fitting one of those god awful Power Boost Valves.
Golden I never knew that about the cold start working under acceleration, however..... How does the cold start valve know when you are accelerating?? I thought it only has two wires connected to it, from the thermotime switch and the thermotime switch. I understand about the WUR and accelerating, just never knew about the cold start valve doing it.
Gareth I can't remember the exact wiring but the cold start injector is used for cold load enrichment. Pigbladder, do you still have the by-pass valve fitted and working?
I thought the 5th injector was switch bearth via the TTS, so only to wires, one power and one switched earth! When i had my kangarooing probs, unplugging the eletrical connection on the bypass cured it also, but it was the module in my case!
Might as well add this here than start another thread. I've got a weird fault on my car, hoping it's an air leak which will be cured by the new engine build (manifold gaskets etc etc) Starts on the button, runs at fast idle when cold, but after a minute or two of running it will hunt on idle and on light throttle down the road it will jerk if not on the throttle, sounds/feels mixture related to me. Once the engine is warm it idles ok, bit lumpy but then I've got a non standard inlet cam, and drives fine with no part/light throttle jerking. Some good tests mentioned in the thread so far, will try them when it's back together if it's not just an air leak..
gvk, sounds like you need a fuel gauge on yours...i can make mine hunt on warm up by fiddling with the pressure
