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. Presumably I need to set the 2 config items in Megatune to P259, channel 5?
etc...
A Lambda table has also been created, but obviously won't do anything until the wideband sensor is installed.
Cranking and CLT warmup settings are pretty much OK as the default. They can only sensibly be tuned by experiment anyway...
No idea what to do with acceleration enrichment right now. I guess it's something that you can worry about when you have a running car.
Sanity check:
I've been through everything I can think of now, so time for a sanity check before I do some damage... I've written up all I can remember doing last night but something is bound to have been forgotten.
What else do I need to do/check before I can fire the car up to see if it will run?
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...
BTW, Feel free to join the IRC chat, see ChatViaIrc page
Progress so far
Well, the car now runs. It still won't idle because I've not got the stepper to work properly. This should just be a case of time and searching the wiki...
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 to trace the 2 all black wires I needed to reconnect as they were mixed in with grounds and all sorts.
Now the LCD rev display is showing half the RPM again. I've not changed that bit of the config (as far as I know), so I'm a bit confused there...
The car doesn't run all that well. There's a slight misfire above 3000 RPM (must be fuel related, as VEMS isn't controlling spark), and the temperature readings still aren't right. Looks like it's back to Easytherm for an evening...
Can anyone point me in the direction of help regarding acceleration enrichment?
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