Fuel Settings
Wiring
Injector wiring was completed & tested last night. It looks better than the factory wiring!
Also took the time to hoover out the soil and powdered grot from engine. (Best not to ask...) It looks a whole lot cleaner now.
[Picture!]
Config
I think that's it for the electrical bits, so it's time to make a config!
VE Table
My VE table estimate using the estimator from the Megasquirt website:
[need to add table - it's not with me here.]
If anything, it's a little optimistic - which is no bad thing for a 1st attempt as it only means too much fuel.
Injector size & timing parameters
I have estimated the size of Rover v8 injectors at around 210 cc/min. I have used just over middle-of-the-road values for opening times based on stuff found in the wiki [add link!!]
Does anyone have more accurate info? They aren't flow matched from the factory and are quite old, so given the tolerances for them reported on Piston Heads it'll do for now. (I plan to change the injectors shortly anyway - and when I do, they will be flow matched and tested.)
[add config section for injector parameters here]
Any comments would be appreciated
Injector firing order
I will be running banks of 2 injectors (so there are 4 banks) until I get the cam trigger working (this can't be done until my coils arrive).
- Is the correct way of doing this to repeat the group of 4 items in the h[0] table?
- A: i would configure them sequential anyway (drive one injector at a time) instead of banked. On the 4 and 6cyl engines i've tuned that has worked the best. Also when you have wired this way you are free to change to low-z injectors any time, also configure them banked if you really want to//Emil
- Agreed that sequential is best. I just can't have it yet as I have no cam sync signal at the moment (only have crank trigger), so can't tell which phase the engine is in.
- Or are you saying this doesn't actually matter and it'll fire the 2 injectors anyway if it can't find the camsync?
- Yep this works fine without camsync, just set up alternate injector 7...0 and fill in the injector table with all outputs, 0x01 to 0x80
- That saves a load of bother! Thanks! I think you mean outputs 0x01 to 0x80 though?
- Yep this works fine without camsync, just set up alternate injector 7...0 and fill in the injector table with all outputs, 0x01 to 0x80
- Low-Z injectors seem expensive and quite rare to me (only seem to be used on Japanese cars). I'll be sticking with high Z ones as they're easy to get.
- I was lost in the small but high powered 4 cyl turbo world, where we usually get aftermarket injectors (500CC/min and up), and good large injectors are always low-z, sorry for that.
- That's for my other car to deal with! (Modified Impreza STi RA with 550cc/min low-z injectors...) The Griffith will survive with 400cc/min high impedance still can be fuelled to >350 bhp.
- I was lost in the small but high powered 4 cyl turbo world, where we usually get aftermarket injectors (500CC/min and up), and good large injectors are always low-z, sorry for that.
- A: i would configure them sequential anyway (drive one injector at a time) instead of banked. On the 4 and 6cyl engines i've tuned that has worked the best. Also when you have wired this way you are free to change to low-z injectors any time, also configure them banked if you really want to//Emil
Fuel pump
Fuel pump relay has been connected. I'm using EC36 pin15 - P259 channel 5. I'm using 3.5 seconds for initial prime and it continues for a second after the engine stops. Unscientifically measured from the previous ECU.
etc...
A Lambda table has also been created, but obviously won't do anything until the wideband sensor is installed. Bought some bosses for the exhaust and lambda should go in this weekend.
Cranking and CLT warmup settings
It was cold last night (around freezing) so I took the chance to sort out cold start. A lot of fiddling later and it's acceptable, but not brilliant.
[ADD CONFIG ITEMS]
Acceleration enrichment
No idea what to do with acceleration enrichment right now. Can anyone point me in the direction of help regarding acceleration enrichment?
- Dont worry about this,first try to get running the car through the whole RPM range.You must have a basic VE table first,Than you can play with the numbers (on a warm engine),and see when is it best.You floor the throttle,with the same speed for 4-5 times ,and see what happens on the WBo2.Im currently using 0.2s accel time.I tried different numbers in the rate / value fields,and a linearly increasing (from bottom to top) is what im currently using.oh yes ,and use TPS based accel enrichment!
[ADD CONFIG ITEMS]
Idle Air Control
The idle stepped does something, but I'm not confinced it's right. I connected the 4 wires from the stepper to the A,B,C & D channels (on the EC18 connector) going clockwise round the motor looking at it from the connector end. What do I need to set the step sequence as?
Things I'd like some help with:
Idle afterstart RPM (added value?) - Is this simply adding (say 100) to the idle speed when the car is first started?
Idle afterstart duration (s) - the duration to do the above for?
IAC afterstart (steps per 160 rpm) - don't understand what this is getting at.
Max steps to extend - total number of steps the motor can do??
IAC step sequence - Don't know about this. There was a page about it, but I've lost the link.
stepper speed (ms) - How long the motor waits before another step?
iac_conf RAW - no idea! something to do with raw hex config?
Idle PID tables - don't get this at all.
See the IAC section of: MembersPage/MarcellGal/EngineSwap/AirFeed
Progress so far
Well, the car now runs, and it has taken me to work. Short 6 mile trip. Initial results are good. The fans come on when they should, the engine warms up at a sensible speed, hot start is excelent, the engine is reasonably smooth in operation, but could be better!
Bad points are:
- The coolant and intake temperatures are still a few degrees wrong (better than before, but still wrong)
- The VE map is not at all refined
- Idle settings aren't right yet - all help appreciated
- Acceleration enrichment is not right - again, all help appreciated.
- Cold start isn't very good yet. (Limited testing oppertunities)
I removed the old engine wiring loom. This might be considered rash. Indeed it was, because it stopped the fuel pump and starter working! Even though they weren't supposed to be connected to that part of the loom!! It seems TVR re-used part of the Rangerover loom, including where the rangerover immobiliser plugged in. (This was bypassed for the TVR immobiliser) It took 3 hours in the cold and dark evening to trace the 2 all black wires I needed to reconnect as they were mixed in with grounds and all sorts.
I suppose the moral here is don't do anything like this if you need the car the next day!!
note
Keep in mind that the lambda table is always used in fuel calculations, but indeed _also_ for supplying the ego controller with target lambda values, be sure to fill it with sane values.
Thanks!
The reference table you created with VE estimator from Megasquirt site might be VE * Lambda, while ours is pure VE, it can be needed to divide the table you created by the lambda table you put to get an accurate estimate, however during the tuning session it is easily fixed.
It's definitely pure VE. I did check that. But it's going to need tuning anyway...
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