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Hi Peter,

I re-set the timing which sorted the pinking.

 

Neil,

I set the VE to 100 in the area of the table where coasting occurs. It has helped a lot. But it still wants to shunt while in 4th, 3rd gear under 30mph coasting. Also wants to shunt in 2nd gear slow corners. I'm not sure what going over 100% VE will do. Perhaps I will look a reducing the AFR is that area as well.

 

Cheers

Steve

Steve,

I dont understand. How can you set the VE? I see from Markus' table it is being used as another name for MAP, manifold absolute pressure. But they are not the same. VE , volumetric efficiency will change with MAP and rpm. On other words, for a given MAP, VE will drop at high rpm because cylinder filling doesnt keep up with MAP, and at low rpm when the inlet valve closes late and fails to trap air. For the stock TR6 engine max VE is around max torque rpm, ca 3500rpm.

I would invest in a vacuum gauge to measure MAP and an exhaust wideband ( UEGO) AFR gauge. You can then measure both while driving. Then you can tweak the mixture anywhere on the efi map without having to guess at settings.

Peter

Edited by Peter Cobbold
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If it's like the MS, VE is short for volumetric efficiency but it's a only a notional value and just a way of entering a value for fuelling and can be over 100%. If it works the same way as MS, 100% would be super-rich for small throttle openings.

 

Do you not have an O2 sensor? A wideband O2 sensor makes tuning a hell of lot quicker and easier, possibly even automatic dependent on what your ecu is capable off.

 

Nick

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Evening Peter,

My software has a VE table. MAP y axis, rpm x axis. I increased the VE values to make the mixture richer is the area where coasting occurs.

 

Steve

Steve, I see, but its a weird use of VE, aimed I think at getting an air mass flow figure to then set the fuel flow. VE even at its best would be 85% for a TR engine. I guess the table has a notional fixed AFR that resetting the VE value above 85% richens. I agree with Nick a UEGO would allow you to determine that AFR for real.

Peter

Yes set the 'VE' to make it really rich where the hunting is happening.

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Thanks for all the input. I recently fitted a fast road cam and didn't have time to get the system tuned in. I had a problem with idle and reduced the VE which helped but I guess that has added to the shunting effect.

 

Ahaa, so ye bunged ina hotter cam,

moer duration,or just lift

 

If its moer durationee, then ye need t,bung in moer fuel at lower settings

aound idle an upto 13-1400 rpms

mainly along the bottom VE line

 

10% line should be OK, butt, I bunged in moer fuel at 800-1600 on the 10% line.

As for colde starting / idle, then fuel NEEDS to be took oot

esp the cranking fuel

reason, the air movement is slower,so fuel kills it by being over richat crank speeds.

 

Also, where is yer Fuel cut off set too.

mine is set to nok fuel off above 1100rpms

At low throttles, it can jerk a wee bit if not careful wif throttles /revs

 

try disconecting it, see if this cures it

And ye may have it set wrong too,

like on for TPS and load and revs, cant ev em all, as one is fighting against the others.

Disconect the feature, and see if that helps

 

Peter, thee,s are Alpha N systems, wid a throttle pot

the fuel is given to what the figure in the box says,

there aint no MAP or vacuum in effect here, its just basic look an read tables

the image I shown was for ign, but fuel map is exactly the same layoot

but in fuel figures needed, no IGN numbers

 

fuel map figs

 

M

post-12368-0-38025000-1476561411_thumb.jpg

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Thanks for all the input. I recently fitted a fast road cam and didn't have time to get the system tuned in. I had a problem with idle and reduced the VE which helped but I guess that has added to the shunting effect.

 

Ahaa, so ye bunged ina hotter cam,

moer duration,or just lift

 

If its moer durationee, then ye need t,bung in moer fuel at lower settings

aound idle an upto 13-1400 rpms

mainly along the bottom VE line

 

10% line should be OK, butt, I bunged in moer fuel at 800-1600 on the 10% line.

As for colde starting / idle, then fuel NEEDS to be took oot

esp the cranking fuel

reason, the air movement is slower,so fuel kills it by being over richat crank speeds.

 

Also, where is yer Fuel cut off set too.

mine is set to nok fuel off above 1100rpms

At low throttles, it can jerk a wee bit if not careful wif throttles /revs

 

try disconecting it, see if this cures it

And ye may have it set wrong too,

like on for TPS and load and revs, cant ev em all, as one is fighting against the others.

Disconect the feature, and see if that helps

 

Peter, thee,s are Alpha N systems, wid a throttle pot

the fuel is given to what the figure in the box says,

there aint no MAP or vacuum in effect here, its just basic look an read tables

the image I shown was for ign, but fuel map is exactly the same layoot

but in fuel figures needed, no IGN numbers

 

fuel map figs

 

M

Markus, Thanks. Steep learning curve for me. I didnt realise there's no feedback from MAP, it runs on just rpm and TPS.. Peter

Edited by Peter Cobbold
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