mark105 Posted August 28, 2011 Share Posted August 28, 2011 so go the skyline running today. started of rich as fuckery. sorted that out to the point now where fuel is backed of that if i back it off any more it wont idle and just die. i have the throttle butterfly's closed right up against the factory stop positions and at this position it will idle at bout 1000rpm. but i have the problem of it wont stop fouling the plugs. like i can see on my wide band the cylinders stopping firing and the gauge just leaning out. soon as i crack the throttles and give it a rev it comes okish but burning of the build up is some what of an issue. timing is at about 11 deg at 1000rpm, possibly to little? im not sure. ive got tuning the fuel map side of things down but tuning the ignition is some what a bit of guess work for me at current. so im stuck at the point of do i just suffer a 1200-1500rpm idle to make this idle with out fucking plugs or am i missing something here? Quote Link to comment Share on other sites More sharing options...
mikuni Posted August 28, 2011 Share Posted August 28, 2011 So its running rich at idle, thats the issue that you need to resolve. You can do one of 3 things that I'm aware of; - give it an idle control valve controlled by the ecu - crack the throttles a little and back the fuel off - give it a slight vacuum leak and back the fuel off I did the 3rd on my Chevette because I'm simple and lazy Quote Link to comment Share on other sites More sharing options...
mark105 Posted August 29, 2011 Author Share Posted August 29, 2011 yeh im probably going to go with option 2. i have no idle control and no means to induce a vacuum leak any other way. seems i may have gone about it wrong in the fact that i should have left some air going in and tried to get something in the way of some AFR's rather than being all nah you dont need any air now lets play with AFR's oh wait your just rich all the time cause there is no air, whoops. i was more worried about making it idle slower instead of 2000rpm as map is all a bit shit still. Quote Link to comment Share on other sites More sharing options...
mikuni Posted August 29, 2011 Share Posted August 29, 2011 If you did want to use an idle control one I have a stack of simple bosch external stepper motor ICV's and you could have one of those. I personally don't think its worth worrying about right away, would be better to just get it running well enough with cracked throttles and then something to play around with later if you have a spare I/O from your squirt. On my shove the only issue it ever had was occasionally it couldn't catch the revs when they dropped fast, so would sometimes stall when coming to a stop, and obvious issues not idling when cold. Didn't bother me though, was just like driving a crappy old car still, which I liked. Quote Link to comment Share on other sites More sharing options...
kpr Posted August 29, 2011 Share Posted August 29, 2011 i just ran mine cracked open. for cold start i rig'd up a tvis solenoid to supply vac to the standard dashpot on the 20v throttles. to crack throttles open some more. and used the ecu to switch it at 50-60 deg. worked alright and will give correct fueling still, if tuning in tps vs rpm (alpha n) 11 deg at idle maybe a little low. try 15 . best idle afr wise, will usually be similar to max power afr. so start around 13:1 or so. then lean it out till it starts to idle junk. then richen it up a little Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted August 29, 2011 Share Posted August 29, 2011 L series had a timing of 8 degree stnadard i think. Fuck i like your idea of tvis solenoid. Will be adding that to my memory banks. Quote Link to comment Share on other sites More sharing options...
Spencer Posted August 29, 2011 Share Posted August 29, 2011 Yea love the solenoid on the dash-pot idea As for timing Id run more at idle, as KPR says 15deg would be sweet, shit my car probably runs about 20 deg in at idle and loves it. Quote Link to comment Share on other sites More sharing options...
DJZ Posted August 29, 2011 Share Posted August 29, 2011 How strong is your vacuum signal if you are using a map sensor? Quote Link to comment Share on other sites More sharing options...
mark105 Posted August 29, 2011 Author Share Posted August 29, 2011 yeh i tried tweaking the ignition map up to 15 today for idle but it was super unkeen on that idea so i think when i can get another set of hands out there to help me again i will reset my base timing as when i upped to 15 deg started poping out the intake. i got a 5 thou feeler gauge after dad showing me on a DCOE that it should be enough for a not to bad idle so i cracked my trumpets open by 5 thou and hello 2000rpm idle. took some fucking with to get back to operating temp but once i was there it just sat at 2000rpm at about 12 AFR. so i tried to lean it of a bit to slow it down and it just sped up to bout 2500rpm at about 13-14 AFR then if i leaned it out any more than that the engine would get to about 15 AFR and would only stay there for a split second or 2 before just leaning out till it died. then i had to go back through VE map and up everything by 5 till it would even run again. so its seeming like it needs fuck all cracked open on the throttle butterfly's to go. so im thinking i might need to back my butterfly stop back a 1/4 or 1/2 a turn and see what that does to the idle. im also going to confirm my injectors are the size i thought they were. i brought them as RB25DE Neo injectors which from the info i have found says they are 260cc injectors but if i can adjust a VE table bin by 1 and the car just leans out and dies i have a suspicion that maybe they are bigger than that meaning my adjustment of them might be jumping in far to big a value each time. im not 100% sure just a theory i thought i would eliminate from the list of things it might be. sorry i guess i should have mentioned im running entirely alpha-n. so no map sensor. Quote Link to comment Share on other sites More sharing options...
kpr Posted August 29, 2011 Share Posted August 29, 2011 kinda skimmed over some of that. but sounds like you may have too much advance.try reset base timing as you said. it should idle all good on 15 deg (total advance) much less and will start to heat up. too much idle advance and little air, can make it do what you describe. will want to stall out easy. Quote Link to comment Share on other sites More sharing options...
mark105 Posted August 29, 2011 Author Share Posted August 29, 2011 hum ok thanks for that. i will revisit my base timing and see where that gets me. Quote Link to comment Share on other sites More sharing options...
mark105 Posted September 3, 2011 Author Share Posted September 3, 2011 seems my modded dizzy is to blame, i had the timing set right but it looks as though some cross firing is occurring which is why its seeming it is heaps advance. so have made some more mods and hopefully this fixes the problem. Quote Link to comment Share on other sites More sharing options...
keltik Posted September 3, 2011 Share Posted September 3, 2011 Do you run a throttle position sensor? If you do, is it still registering closed throttle when you have them cracked for idle. If it wasnt calibrated right and tripping the throttle open parameter (instead of using the idle maps) then i can imagine having these kinds of problems. Quote Link to comment Share on other sites More sharing options...
kpr Posted September 3, 2011 Share Posted September 3, 2011 hes running alpha n (tps vs rpm) so none of those issues should exist. unless he is inducing a vac leak to rase the idle, which would lean it out Quote Link to comment Share on other sites More sharing options...
keltik Posted September 4, 2011 Share Posted September 4, 2011 But even with TPS vs RPM (which is what i also run) there has to be a cutoff point set where idle control takes over. On my Link its 0.8% TP and RPM<1600. Or does this thing not run an idle cotrol solenoid or seperate idle trim tables? Admittedly i dont know shit about ITBs. Quote Link to comment Share on other sites More sharing options...
kpr Posted September 4, 2011 Share Posted September 4, 2011 doesn't sound like he is running anything no. i'd be ditching all the fancy stuff to start with, if he was. start with a simple setup both tune and mechanically. get it running nice, and add to it if required. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted September 4, 2011 Share Posted September 4, 2011 Nah, no idle control, no idle bleed holes or anything like that. Idle is solely controlled by how far open the throttles are open. The problem is that even the slightest movement makes a noticeable difference in airflow, but without enough movement of the TPS to register a change in throttle position. I guess that's what you get with 6 x 45mm throttles though. We have got it running a lot better now though, disabling the bloody wide band correction helped a lot as the engine was often misfiring and fucking up the A/F readings, which it then tried to correct.. In any case it still doesn't want to idle below 1100 or so. I'm thinking a better ignition system may help, so Mark needs to wack on the MSD he has to see what happens. Quote Link to comment Share on other sites More sharing options...
kpr Posted September 4, 2011 Share Posted September 4, 2011 hmm yeh make sure all the corrections are off. post a screen cap of your fuel table. sorry if i missed it, but what ecu are you running? megasquirt? Quote Link to comment Share on other sites More sharing options...
mark105 Posted September 4, 2011 Author Share Posted September 4, 2011 yeh as yowzer said it is running alot better now. my dizzy wasnt helping but that problem is now all solved, pretty much on with the tuning now. some adjusting of the fuel tables was required to put better resolution into the idle area so it was actually tunable. unfortunately with the MS1 i only get a 12x12 table which although is ok with how sensitive this thing is at idle it would be nicer with some slightly bigger tables. idle is still proving some what difficult to get right due to how bloody sensitive it is with anything to do with it. but im at a point where if my radiator had not sprung a random leak and the car was back together i could start road tuning now. and yes it is a MS1 chip with a V3.0 board. Quote Link to comment Share on other sites More sharing options...
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