another Alfa Romeo conversion

[blownvp]

if it seems to be adding steps on accel check your tps signal is stable and you havnt got a tps voltage low code it will use a map signal for tps .

[Holden202T]

i agree screw in the throttle stop till IAC steps drop to about 20 steps at warm idle

[festy]

I adjusted it to idle at about 22 steps, and dropped the IAC throttle crack numbers down a bit and it's much better now, thanks guys

[Holden202T]

yeah as a general rule i try to aim for 15-20 steps at warm idle, if you find the engine stalls a bit you can always screw the throttle a bit more and drop the steps .... you just really need to make sure theres not zero steps cause that then means if the idle is too high the computer can't lower it with the IAC solenoid.

[festy]

I had to make a new exhaust after ripping the old one off on a bump and then driving over it - the new one is 2.25" side exit with an 18" hotdog, and sounds so much better than the old box muffler

The wideband still hasn't arrived, so I've been trying to get a decent KINJFLOW sorted. According to the spreadsheet, the magic number should be 0.086 (500cc cylinders, 24lb injectors) but it fouls the plugs within a few minutes, and the exhaust is smokey at idle.
With a bit of trial and error, 0.065 seems to be in the right ballpark - but that seems a long way off the spreasheet numbers?
I'm not sure what fuel pressure the spreadsheet uses for it's calculations, but I'm only running 2.5 bar...

I went for a quick drive after pulling a bunch of timing to be triple-safe, but forgot I'd left the rev limiter set at 3000 rpm

Shortly after that I lost oil pressure, so limped back to the shed. I'm hoping it's something simple

[antus]

The spreadsheet doesnt assume pressure, it assumes flow. The rating for the injector will be in the form of xxx cc/min at yyy bar of pressure from the manufacturer. 2.5 bar is low, that would be by the inj rate was so far out.

[VX L67 Getrag]

Oh No loss of oil pressure, I assume you pushed it without oil pressure?

Could be nasty if it was running dry!

[festy]

ok, thanks antus - that makes a little more sense.
I'll double check the injector and FPR specs, I might have it wrong.

vx: I didn't push it when the oil pressure dropped - I was already slowly heading back watching the gauges because the temp was getting towards an uncomfortable level (looks like this water pump is RS as well) and noticed the oil pressure drop to 0. It was still showing a bit of pressure with a few revs, but none at idle.
It hasn't lost any oil, and made decent pressure once it had been sitting for a few hours - so I might stick a mechanical gauge on it to rule out sender/gauge issues before pulling the engine

[Holden202T]

the kinjflow calculator is not perfect and holdens tunes were never what the calculator worked out, there was always a fudge factor in it.

to be honestly you really need to get the WB in there and tune the WOT area, you want to aim for the highest point in the 95/100kpa columns to be about 90, if its getting up toward 100 then you can adjust the kinjflow to get it too about 90, then you also need to adjust the rest of the VE table to suit the percentage change in kinjflow.

at the end of the day the best number is the one that gives you about 90 at max and nothing at zero

[festy]

The 12p XDF only shows 2 decimal places for injector displacement, so my setting of .086 was actually .09something
I changed my xdf to 4 dp, and that appears to give much finer granularity.
Out of interest, what's a "normal" fuel pressure, if 2.5 bar is considered low?

A bit of googling showed plenty of discussions on the alfa oil pressure senders going bad and reading 0 at idle when hot, so I'll swap another sender in and see what happens.
I've ordered a new water pump from the UK, it was about $100 cheaper than getting it locally (if SA is still local...) so will be waiting a while for it to arive.
I wired up a CEL today, and spent ages playing with a resistor making it flash out morse code, heaps of fun
I got most of the wiring tidied up and mounted the ECU, fuse panel, relays etc - not much really achieved today really but I'm a slow worker