Basic Tuning help required

[gingerwinky]

YOU GUYS ARE AWESOME!

used one of the blanks on the trumpet base to use as a MAP feed, drilled and tapped a hole into a plug, fitted a brass air piece then an air hose between the fitting and the computer and blow me I get the figure I'm searching for, in the immortal words of tommy cooper ' Just like that'

a snapshot of the readings I'm now getting on my computer are:-

revs 740-840

temp 76 deg

pulse width 1.9

duty cycle 2.2

MAP 34

MAT 20

air fuel ratio 28 the needle is hard over to the right and the gauge is in red

ign adv 19.9

a big step forward. judging by the air fuel ratio reading the lambda sensor is stuffed and also some readings I took using a multimeter the other week suggest the same.

marc, I have built this landy as a general runaround so don't intend him going near deep water, I have a megajolted series/90 hybrid for that but thanks for the heads up on the rope seal. the engine came in bits and it wasn't until I started to assemble it that I realised it was an early block, only paid £15 for it!!!

again, a big thankyou for the help

andy

[FridgeFreezer]

A couple of things to check with the lambda sensor:

- Wiring polarity: usually the BLACK wire is "signal" and GREY is "ground" but not always - worth a check with a voltmeter.

- Clogged up: Running massively rich for as long as you have can clog the sensor, it may clear after a good run, or you can remove it & heat it with a blowlamp to burn off deposits - get the tip just cherry red, no hotter, and you can watch the sensor voltage come up on a voltmeter.

- Is it a universal Zirconia type sensor (0-1v) and not a Titania type (resistance) as fitted to RRC & Disco?

[gingerwinky]

Hi Nige,

Thanks for the reply, the sensor is one that you supplied when I bought the kit from you some years ago and I have the sensor wired up as you have suggested

Andy

[FridgeFreezer]

Who's Nige?

[dirtyninety]

ANDY

FridgeFreezer is John, electronics and megasquirt Guru

HybridFromHell is Nige -- from megasquirtv8

[FridgeFreezer]

Let me fix that for you:

FridgeFreezer is John, some bloke off the internet electronics and megasquirt Guru

HybridFromHell is Nige -- from megasquirtv8

[Hybrid_From_Hell]

Oink

[gingerwinky]

I keep saying this but....you guys are great

having put some heat on the lambda sensor the cheeky little chap works a treat.

the readings I am getting now are:-

at 73 degrees

revs 800-ish

pulse width 1.9

duty cycle 2.1

MAP 30

MAT 21

Air/Fuel ratio 13

Ign Adv 19

I have checked the engine for TDC, when no.1 cylinder is at TDC the crank pulley timing pointer reads TDC too.

With the engine idling at 800-ish and at 73 degrees temp the computer reads 19 degrees advance and the crank pulley reads the same.

The spark table reads:-

Trigger Angle 0

Trigger Angle Addition 0

Cranking Advance Angle -10

Hold Injection 0

Spark Output Inverted Yes

Experimental Oddfire No

Fixed Angle -10

Trim Angle 8

Now, the engine and the computer are reading the same for ignition advance but nowhere near 8 degrees for an average v8, is this where I play around with the fixed angle and trim angle figures?

I removed the PWM to fault diagnose, should I refit it?

As always, thanks for reading this and any advice will be greatly appreciated

Andy

[FridgeFreezer]

Remember that trim angle does not affect fixed angle, it only affects (offsets) the ignition table values. I set the bottom corner of the ignition table (or the whole table) to a fixed value and then move the trim angle until the timing light agrees with the value in the table, then re-load the ignition map... which of course you remember to save a copy of before setting it all to a fixed number

[gingerwinky]

So, just had a look at my spark table and it says that at 800 rpm and 30 kPa the ignition advance is 11

The Idle Advance Settings read:-

Idle Advance -8

TPS Threshold 26

CLT Threshold -18.3

Wait Time 3

What I am struggling with is the amount of tuning information out there and some of it contradicts each other, can someone suggest a definitive document to use please and preferably one with big letters and pictures.

Again, thanks for any advice

Andy

[Bowie69]

Tuning what?

[gingerwinky]

the megasquirt programme

[Bowie69]

Umm?

Fuel, spark, VE, warm up, idle, AE....?

[FridgeFreezer]

What Bowie asked - each thing (fuel, spark, warmup, idle) can be an entire subject on their own. As an example, the code in the GM ECU for the LS engine that stabilises the idle when you turn the air-conditioning on has more lines of code than the entire Megasquirt code!

I'd be inclined to read posts by Nigel on this forum as it's most likely to be relevant to your setup.

First off, have you actually got your trim angle set correctly now?

This is what I was proposing to do to get the trim dialled in, set the whole table to 10deg and adjust trim angle until that's what really happens:

[Quagmire]

From your post it sounds like you have ms2 or ms3? Dont think ms1 has specific a specific idle advance dialogue.

[gingerwinky]

yet again, thank you for your input, you guys are AMAZING!!!

so, as suggested by fridge I changed the spark map settings as he said (saving the original map first) then messed around with the trim angle values.

I am now running 0 degrees of trim but both the computer and the engine are showing 10 degrees of advance and wouldn't you know it he's developed a misfire but I know which plug is tits.

do I now reload the original map and then take him for a spin?

Andy