Traka2015 Posted August 23, 2015 Share Posted August 23, 2015 Got my lovely new megasquirt kit nigel (great bit of kit ) All installed on my 3.5 v8 but wont start on petrol fires straight up on lpg blos carb I have no negative pulse going to injectors and injector led doesnt flash on ecu I have live feed to injectors and fuel disconnected ecu and momenterally ground injector pins (32,33,34,35) to earth and you can here injectors click attempt to start and it runs briefly Checked tps calibration with nigel incase flood control was activating swoped vr sensor wiring round no spark and wont run on lpg and no rpm recorded on megatune after a sleepless nite last nite remembered that I had joined injector wires together before splitting into four for each bank so pins 32&33were briged bank a and pins 34&35 bridged bank b sorted that this morning and continuity checked with injectors unplugged no continuity so good there but still no injector pulse / led could i have damaged ecu by pins being bridged ? Checked pip signal on oscilloscope got a good 0v 12v square wave at ecu checked all wiring through again everything works as it should bar injector pulse only other possibility I thought of was my megatune looks different to nigels and had a bit of a do with itself when i first connted it to ecu could i have wiped program or something the other two leds are working as they should d15 comes on on cold start and d16 flashes when throttle is buried attached a pic of my megatune on petrol cranking no start if it gives anyone a clue what ive done wrong any help greatly appreciated Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted August 23, 2015 Author Share Posted August 23, 2015 Quote Link to comment Share on other sites More sharing options...
mickeyw Posted August 23, 2015 Share Posted August 23, 2015 Sounds like the fuel pump may be cutting out after initial start. I'm not familiar with the MS software, so I don't know how the ECU and fuel pump are connected. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted August 23, 2015 Share Posted August 23, 2015 - When you crank it, do you get an RPM reading on the display? - Does the squirt LED flash? - Does the fuel pump run - ignoring the initial 2 second priming pulse when you power it up, does it run when you crank it over? Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted August 24, 2015 Share Posted August 24, 2015 Do you have the resistor pack still in, I'm sure you need it with the 3.5 injectors? Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted August 24, 2015 Author Share Posted August 24, 2015 Fuel pump is running while cranking rpm showing around 200 when cranking everything is there to make it run if you short injectors to earth they click and it attempts to start on leftover fuel got no negative pulse coming out of Ecu injector pins and led not flashing on ecu Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted August 24, 2015 Author Share Posted August 24, 2015 It never had resistor pack for injectors mine is one of the last 3.5 s came with hotwire and ran two catalytic converters from new all injectors were reconditioned last year too Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted August 24, 2015 Share Posted August 24, 2015 Slightly concerned by the 950000% injector duty cycle claimed in your screenshot have you changed any settings? As you are a man with an oscilloscope, any chance you could pop the top off the MS and scope 8-pin IC U4 pins 2 & 4 (injector driver IN) and 5 & 7 (driver OUT), you should have 5v logic pulses going IN and the same or bigger coming out when the ECU is getting RPM. Schematics: http://www.megamanual.com/ms2/pcb.htm Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted August 24, 2015 Author Share Posted August 24, 2015 Not changed any settings but laptop had s do when first plugged in and said something bad could happen can't remember what exactly so injector outputs bridged not a problem then Im away this week but will get oscilloscope on it Monday night and see what i get Thanks Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted August 31, 2015 Author Share Posted August 31, 2015 Just had oscilloscope on it got +5volt -5volt pulses across pins 2&4 and nearly 6volt +- pulses across pins 5and 7 Where do i go next ? Thanks Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted September 12, 2015 Author Share Posted September 12, 2015 Update still not running on petrol been through schematics and injector pins are bridged inside ecu so that wasn't the cause Got it up to temperature running on lpg wue led goes out and rpms drop to around 900 led for throtle blinks when you hit throtle Noticed today that led for injectors lights when warm but ive still nothing coming out of injector pins on megasquirt is it software related and has this 990000% duty cycle got anything to do with it ? Quote Link to comment Share on other sites More sharing options...
need4speed Posted September 12, 2015 Share Posted September 12, 2015 I can't comment on the tuning as mine isn't even bloody running yet, but John did say he was concerned about your duty cycle. And trust me, when it comes to MS if he's concerned, you should be too... Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 12, 2015 Share Posted September 12, 2015 Slightly concerned by the 950000% injector duty cycle claimed in your screenshot have you changed any settings? As you are a man with an oscilloscope, any chance you could pop the top off the MS and scope 8-pin IC U4 pins 2 & 4 (injector driver IN) and 5 & 7 (driver OUT), you should have 5v logic pulses going IN and the same or bigger coming out when the ECU is getting RPM. Schematics: http://www.megamanual.com/ms2/pcb.htm Also with Fridge and Phil, I am currently betting on your required fuel being completely wrong, probably 0, to get that kind of duty cycle... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 14, 2015 Share Posted September 14, 2015 Been away on holiday... Had a PM from Traka but it's probably easiest to continue everything in one thread: Ive had oscilloscope on pins 2&4 got -5 to +volts pulses across pins and -6 to +6 volts pulse across pins 5&7 with it cranking where would you suggest i go next ? Now, this sounds like the scope is set up for AC or somesuch as it should be 0 to 5V pulses from the CPU going in and I don't believe the CPU would be working it it was managing -5v Regardless, I don't think your ECU is faulty, especially as it's been to Nige for modification & therefore will have been tested on a stim so it's time to check the obvious stuff. You said there was some warning on your laptop about something, that suggests to me you might not have configured MegaTune for your ECU - you need to set it for the version of code you're running which is MS'n'S-Extra 029v - from the file menu, select "Configurator": Then for your car you must tell it the code version you are using or you will get incorrect settings - MegaTune will be looking in the wrong place and setting values in the wrong way in the ECU, this can REALLY screw things up if it's wrong: Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted September 16, 2015 Author Share Posted September 16, 2015 Thanks for your help now running on petrol and lpg Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 16, 2015 Share Posted September 16, 2015 Glad to hear it but what was the problem? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 16, 2015 Share Posted September 16, 2015 Yep ^^^^ So others can learn... Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted September 16, 2015 Author Share Posted September 16, 2015 Changed settings as you said there is no option for029v there is a 029c went for that still says theres a critical error it runs and ive got working guages won't let me download or burn to ecu On mates rolling road now on tuner studio ms working a dream Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 16, 2015 Share Posted September 16, 2015 Can you clarify if you're using MegaTune or TunerStudio? Sounds like you've still not 100% sorted it. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 16, 2015 Share Posted September 16, 2015 Sounds like an old version of MT, without 029v software. Tunerstudio has obviously picked it all up OK now Quote Link to comment Share on other sites More sharing options...
Traka2015 Posted September 17, 2015 Author Share Posted September 17, 2015 We're getting there spent 7 hours trying to communicate with it Bought the full version of tuner studio £44 worth every penny was communicating in minutes still got a flat spot when cold and hunting but will sort that once we get it running right at operating temp Anybody know what A.F.R I shoud be running im not after out and out performance its just a laning and pay and play toy Also anybody got any ignition tables for lpg Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 18, 2015 Share Posted September 18, 2015 There's no one "correct" AFR, have you read through some of the sticky/tech threads on setting up & tuning? Also, unless you have a wideband sensor you should totally disregard any AFR gauge in the software, narrowband sensors can't tell you that. Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted September 18, 2015 Share Posted September 18, 2015 I use a wide band and aim for 14.7. I'm not good enough to tune off a narrow band and mine died after a dunking anyway The wide band controller does have a simulated narrow band output that you could feed into the megasquirt so you could have a go with the auto tune in tuner studio but I've never tried it. As mines an auto and idles higher in park than drive, at the idle point in drive on the fuel table I found setting the map a little rich helped with it picking up. I also found it was hunting a little at idle so I set the 4 squares on the fuel and spark table where it idles the same. Don't know if any of that is 'correct' but it helped me Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 18, 2015 Share Posted September 18, 2015 I'm a muppet at tuning but you want to run richer than 14.7:1 at high load, basically to avoid melting a piston (that's the very, very short version) and Rover 8's like to idle quite rich too. There's plenty of example target AFR maps cropped up in the various threads on this forum that should give a few pointers. Quote Link to comment Share on other sites More sharing options...
Rangie46 Posted September 18, 2015 Share Posted September 18, 2015 search for a thread by bowie called target afr tables with a wideband lc1, I use his afr table at the bottom of his thread myself so a big thank you to bowie, I run at 13.5.1 at idle as I find if I go leaner it starts hunting don't know if that's right or wrong as I'm still learning and reading about all this tuning Quote Link to comment Share on other sites More sharing options...
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