Speeduino install update.

[Fenderer]

Polly Grigora said:

Don't understand why the coils have been supplied from the fuel pump relay

The coils should be supplied directly from the ignition switch switched supply or from an ignition switch controlled relay, Whatever the method used, the ignition coils supply shouldn't be connected into another circuits relay

There is no reason to supply the ignition coils from a timed relay such as the fuel pump is

Well you can argue that with the hundreds of Megasquirt folk that do it this way. Either way, it's not the cause of my issues.

[Fenderer]

Quick update.

- New fuel pump installed -

- New ULN2003 installed -

- Fuel pump primes again YAY! , now getting correct voltage across relay...

Ran great for 5 mins then went horribly lean AFR, too lean for the gauge and won't idle. Unbelievably frustrating!

So etiher I'm still not getting enough fuel or maybe there's a huge air leak...

I'm not convinced I'm understanding how the PWM air valve should be working. Should it be open maintaining idle speed? But how does this affect the mixture. If there's a load of extra air from the valve and no extra fuel then surely it will run lean?

PWM duty below.

[Belle427]

Are you using the standard stepper motor?
The warm up enrichment tool in tune analyze is pretty good, have you run this?
It’s all a bit of a balancing act and takes a while to get right.

[Fenderer]

Belle427 said:

Are you using the standard stepper motor?
The warm up enrichment tool in tune analyze is pretty good, have you run this?
It’s all a bit of a balancing act and takes a while to get right.

No I junked it mainly as it was doubtful that Speeduino would be able to control it so I went with a 2 wire Bosch air valve.

But to be honest I have no idea what I'm doing with it. I can't really get my head around how Speeduino is adjusting for the increased air. There doesn't seem to be any table that maps PWM duty with additional fuel.

If I turn the valve off i,e shut it won't idle at all as the base idle speed is too low so it obviously needs some additional air even when up to coolant temp.

It feels like a fundamental lack of fuelling for some reason, but I have a brand new pump, new filter, injector duties look sensible and it's using the same VE values as when it was originally idling OK before this happened.

I don't think it's an WUE issue as it was fully up to temp and not using the curve and still not idling, running lean,

I don't really know where to go with it to be honest.

[Belle427]

I may be wrong but I don’t think there is a table, you just increase your fuel in the appropriate cells in the ve table and observe the afr.

[Fenderer]

Belle427 said:

I may be wrong but I don’t think there is a table, you just increase your fuel in the appropriate cells in the ve table and observe the afr.

OK, thanks. I'm reluctant to change anything in the table as it ran OK before. I'll just be trying to add more fuel to mask a problem elsewhere.

The big clue is something suddenly changed and made it run super lean. It's off the scale lean. The AFR gauge won't even read it. Should be easy to find but it's beaten me so far.

[Belle427]

Good luck, vac leaks are fairly easy to find.
Are you sure there wasn’t a problem with the fuel delivery side before that has now been rectified?

[ric355]

Fenderer said:

No I junked it mainly as it was doubtful that Speeduino would be able to control it so I went with a 2 wire Bosch air valve.

But to be honest I have no idea what I'm doing with it. I can't really get my head around how Speeduino is adjusting for the increased air. There doesn't seem to be any table that maps PWM duty with additional fuel.

If I turn the valve off i,e shut it won't idle at all as the base idle speed is too low so it obviously needs some additional air even when up to coolant temp.

It feels like a fundamental lack of fuelling for some reason, but I have a brand new pump, new filter, injector duties look sensible and it's using the same VE values as when it was originally idling OK before this happened.

I don't think it's an WUE issue as it was fully up to temp and not using the curve and still not idling, running lean,

I don't really know where to go with it to be honest.

If you want to e-mail me your tune, drop me a private message and I'll reply which will then get you my e-mail address.

The PWM valve needs to be set up with the correct frequency first. Info usually available online for best frequency to use. Various will work but it'll be most responsive at the correct one.

There are two ways you can run PWM idle control - either closed or open loop. Stick to open loop when first tuning as closed loop introduces some automatic variation which makes the tuning process more difficult. You need to set the open loop PWM duty table up with a curve that is based on temperature. Note that the idle position of a PWM valve at 0% duty is usually part open.

In terms of how the fuelling is adjusted, as you adjust the opening of the idle valve the position in the VE table will alter because MAP will change. This will reference a different fuelling point. Tuning the idle is iterative; the valve opening changes the VE reference (MAP) which changes the fuelling, which in turn changes the idle speed. You're looking to balance everything out. Tune the hot idle first; this is your baseline VE at 100% gamma i.e. no enrichments

Go through your tune and make sure all closed loop functions are turned off. PID fuelling being the most obvious one in the AFR/O2 menu. Set to "No Correction" but leave the sensor type at wideband.

Typically when stuff goes suddenly lean it's because some sort of enrichment has ended. Especially during warmup. So something to look at would be your warmup enrichment curve. It should end at 100%. If it doesn't, then once above whatever the final temperature point is, fuelling will revert 100% and you'll get a step change in behaviour. When enrichment ends you're back to, mostly, using your VE table by itself, so that's the thing to get right first at fully warmed up temps.

The other thing you can do is look at the Gamma Enrichment value. That tells you what fuelling is actually being applied, and there are a set of gammas that relate to each individual enrichment allowing you to pick apart where the fuelling is coming from. I've mentioned this before - learning to read the datalogs and establish the causes of things is key to getting it tuned well. Set up auto-logging in TunerStudio so you never miss an event. Also, if something happens then hit the space bar; it'll put a marker in the datalog which will then appear as a red vertical line in megalogviewer.

Edited by ric355 on Saturday 28th May 09:56

[Fenderer]

Yeah it must be the same issue I was having before I fitted the new pump. I'm going to check the voltage at the pump terminals while running and see if that looks OK. The MAP sensor readings look OK on the logs which is pointing away from there being a vacuum leak.

[Belle427]

Warm up enrichment for me was a tough one.
Most people said to taper out of it by 70 degrees but my car didn't like this.
Extending it further is fine but if running on a cooler day I found temps low enough to drop back into it.
Never really got this 100%.

[Fenderer]

OK, I have a solid 13.5v on the terminals while the pump is running, so it's not a wiring or relay issue. No vacuum leaks... It fires but if you look at the log it just gets leaner and leaner as it warms up.

[Fenderer]

ric355 said:

Fenderer said:

No I junked it mainly as it was doubtful that Speeduino would be able to control it so I went with a 2 wire Bosch air valve.

But to be honest I have no idea what I'm doing with it. I can't really get my head around how Speeduino is adjusting for the increased air. There doesn't seem to be any table that maps PWM duty with additional fuel.

If I turn the valve off i,e shut it won't idle at all as the base idle speed is too low so it obviously needs some additional air even when up to coolant temp.

It feels like a fundamental lack of fuelling for some reason, but I have a brand new pump, new filter, injector duties look sensible and it's using the same VE values as when it was originally idling OK before this happened.

I don't think it's an WUE issue as it was fully up to temp and not using the curve and still not idling, running lean,

I don't really know where to go with it to be honest.

If you want to e-mail me your tune, drop me a private message and I'll reply which will then get you my e-mail address.

The PWM valve needs to be set up with the correct frequency first. Info usually available online for best frequency to use. Various will work but it'll be most responsive at the correct one.

There are two ways you can run PWM idle control - either closed or open loop. Stick to open loop when first tuning as closed loop introduces some automatic variation which makes the tuning process more difficult. You need to set the open loop PWM duty table up with a curve that is based on temperature. Note that the idle position of a PWM valve at 0% duty is usually part open.

In terms of how the fuelling is adjusted, as you adjust the opening of the idle valve the position in the VE table will alter because MAP will change. This will reference a different fuelling point. Tuning the idle is iterative; the valve opening changes the VE reference (MAP) which changes the fuelling, which in turn changes the idle speed. You're looking to balance everything out. Tune the hot idle first; this is your baseline VE at 100% gamma i.e. no enrichments

Go through your tune and make sure all closed loop functions are turned off. PID fuelling being the most obvious one in the AFR/O2 menu. Set to "No Correction" but leave the sensor type at wideband.

Typically when stuff goes suddenly lean it's because some sort of enrichment has ended. Especially during warmup. So something to look at would be your warmup enrichment curve. It should end at 100%. If it doesn't, then once above whatever the final temperature point is, fuelling will revert 100% and you'll get a step change in behaviour. When enrichment ends you're back to, mostly, using your VE table by itself, so that's the thing to get right first at fully warmed up temps.

The other thing you can do is look at the Gamma Enrichment value. That tells you what fuelling is actually being applied, and there are a set of gammas that relate to each individual enrichment allowing you to pick apart where the fuelling is coming from. I've mentioned this before - learning to read the datalogs and establish the causes of things is key to getting it tuned well. Set up auto-logging in TunerStudio so you never miss an event. Also, if something happens then hit the space bar; it'll put a marker in the datalog which will then appear as a red vertical line in megalogviewer.

Edited by ric355 on Saturday 28th May 09:56

Thanks Ric355. Great tips here. Will send a message shortly.

[F1natic]

Great info Ric, I would add that having the injector deadtime characterised accurately will also help create the most accurate VE table when all enrichments are off.

[Polly Grigora]

Fenderer said:

Polly Grigora said:

Don't understand why the coils have been supplied from the fuel pump relay

The coils should be supplied directly from the ignition switch switched supply or from an ignition switch controlled relay, Whatever the method used, the ignition coils supply shouldn't be connected into another circuits relay

There is no reason to supply the ignition coils from a timed relay such as the fuel pump is

Well you can argue that with the hundreds of Megasquirt folk that do it this way. Either way, it's not the cause of my issues.

Argue? It's open to debate though. Have never wired ignition coils to a timed fuel pump relay and never witnessed it being done by others of which there are many

I doubt very much that hundreds of people wired their vehicles to the above diagram, if they did they have got it wrong

The relaying method shown in the diagram has also reduced the load on the ignition switched circuits when the ignition is turned from on to off. The above understandably allows current to flow from the alternator diode trio D+, through the warning light and onwards down to earth through the ignition relay coils which in turn keep a supply on the fuel pump and ignition coils causing engine run-on

This is the best part of it

Whoever designed the above circuit came up with a rediculous idea for preventing engine run-on

There has been a diode added in series with the alternator warning light to alternator D+ cable which does prevent engine run-on but also greatly reduces the functionality of the alternator warning light circuit

The above diode should never have been added

Are there really hundreds of vehicles wired as above? Surely not

This leads me to believe that there wasn't much thought put into the design of the circuit and explains the use of a timed fuel pump relay to supply the ignition coils

Below is a method for keeping full alternator warning light functionality while also preventing engine run-on, it didn't take much thought

Anyway, hope you get sorted

[Fenderer]

It's an awfully long time since I posted anything on this but just wanted to post an update to say my Speeduino install is finally up and running and performing really well.

I've still got some tuning to do but the car is already loads better than it ever ran on the 14CUX ECU and the distributor/ coil setup. It starts perfectly, idles cleanly and is much more throttle responsive and generally better to drive.

It's been a massive learning curve and very rewarding. Thanks to ric355 on here, who helped iron out many of the teething problems along the way.