V8 Freak Posted November 1, 2011 Share Posted November 1, 2011 I did some reading last night on some of the MS forums and it was way above my level of comprehension.... So, back in here to discuss with those who can take long words, understand what's going on and translate into short words for the likes of me.... The situation..... I went playing in Wales over the weekend with other forum members. Having a great time, but my truck likes to "bunny-hop" and will not just settle and effectively crawl along unless on a nice climb. I'm happy with it's road performance and on the run home from Wales (Even with some loud pedal moments) I got 18.43 MPG.... Question / discussion part 1 So, rather than try and have everything in one map, I was wondering about a map for off-road and then back to normal for pottering around on tarmac. I'm sure MS (Not sure which hardware / version) can handle using 2 maps, but what can you change on the fly using this method? Is it only spark map or fuel map or can I have totally different closed loop settings as well for example ? (or do I really require a totally different map loaded each time I want a change usage to get totally different settings?) Question / discussion part 2 Crawling.... (Not the sort while trying to placate SWMBO when caught spending money on the 110....) How can I get the engine to not react to stalls as violently and just plod like wot a diseasel does ? I'm sick of worrying about wrecking props and gears by banging back and forth as the engine revs change and just want a map that will effectively hold it pretty steady so I can choose Low range and crawl through lanes.... I'm happy to forgoe anything that we would regocnise as economy (Even compared to the 18MPG) and even limit revs to 3k max and spread the table out more for the lower rev usage... (i.e almost tell MS what I want in the 12x12 table rather than let it extrapolate) Do I go for more advance? Flat / virtually no advance from tickover to 2k? What builds in more torque? Happy to build a second map to play and tune in low ratio, so suggestions most welcome. Neil Quote Link to comment Share on other sites More sharing options...
Dave W Posted November 1, 2011 Share Posted November 1, 2011 Regarding the map switchover, it can be used to change both fuelling and ignition but you can't change ego settings etc... You shouldn't need to use two maps to achieve what you want. EGO isn't the best way to get good economy (quite the opposite in fact) and below 1500 RPM it has a tendency to cause "surging", particularly noticeable in low box. I'd concentrate on getting a decent mix in all areas of the map between idle and 1500 rpm with the EGO switched off. use a slight increase in advance at the bottom end of the idle rpm (at around 600) to help avert stalling. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 1, 2011 Share Posted November 1, 2011 I'm no expert but you can, as Dave says, slope the fuel & ignition maps at the bottom (stall) corner to stabilise idle & help crawling. The PWM idle valve makes a difference too. EGO should not be active below 1500rpm as it's not useful and leads to hunting. You may also want to change the accel settings, I found mine when TPS-based was activating accel as the truck bounced over every pebble in the road, reducing the low end of accel sensitivity stopped that. You can also switch to MAPDOT instead of throttle position change, which may or may not help (I've never played much with it and can't even remember which I set mine to Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted November 1, 2011 Author Share Posted November 1, 2011 Ok.. EGO off under 1500 already but will look at acceleration settings. Will look at idle valve settings as I have a copy of the Bosch in there at present and closure values differ a lot to typical Bosch as posted on this forum. (25 on Bosch and 32 on mine etc.) Have Bosch valve spare so will change this weekend and use suggested settings from the board. Thanks for the suggestion of the extra advance Dave. I remember a discussion somewhere on here talking about that valley look in the timing map to help with stalls.. Maybe a bit of general playing this weekend to see how stable I can get it below 1500 crawling around the farm. When you say there are other ways to get improved economy, can you explain a little more please? I know this is potentially introducing yet another thread of discussion, but I'm keen to learn.... Any more ideas / things to try? Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted November 2, 2011 Share Posted November 2, 2011 You can try and make an engine smoother by retarding the timing and richening the mixture around your crawling areas. Have a nice slope on it too as FF suggests. You can also play around with the closed loop idle valve settings to allow it to correct the drop in revs more rapidly. Be aware, that correcting too fast will result in instability (again...bunny hopping....) Quote Link to comment Share on other sites More sharing options...
bobtail84 Posted November 2, 2011 Share Posted November 2, 2011 Ok..... If and this is a big if.. you have AE set about right and both fuel and spark maps give you a crisp ish exel and pull you can play with the PWM settings. This has taken me quite a while to get right but BBC posted some good setting and I worked from those mind you Cpt Birds eye was still an able seaman back then so you might have to look in the 1st doz or so pages of HFH's "How to" thread but it's there. If I'm on a hill or just need a "diesel" pull with out a hand break start I just lift the clutch and let the revs build on the PWM valve then off of the foot brake and away we go. Jeff Quote Link to comment Share on other sites More sharing options...
zoltan Posted November 3, 2011 Share Posted November 3, 2011 What is your normal hot idle speed? Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted November 4, 2011 Author Share Posted November 4, 2011 Normal hot idle is 850 RPM Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted November 5, 2011 Author Share Posted November 5, 2011 Well I looked at other 4.6 spark maps and decided mine was in need of a change. More advance as suggested in the lower rev ranges and I changed my PWM valve for a genuine Bosch one. I did the map changes first then took a drive with Tunerstudio working it's magic. Then when nice and warm, I set about the PWM valve. While ticking over I checked to see if the recommended 25% was it's closed position. To my surporise it was higher than my old one which was 32%. Looking into the valve, it actually closes at 45%!! So knowing it's closed point, it was duly installed and tested.... New advance and BBC's PWM settings seem to have done the trick. I was able to amble round the farm this afternoon in low ratio without very much hopping or rocking back and forth on the running gear. Not much to climd or decend rund here, but it felt a lot better. More playing soon to see if I can improve it further. Tanks for the comments and suggestions above. Looks like your combined knowledge and help has found the solution once again. Neil Quote Link to comment Share on other sites More sharing options...
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