Questions...

[CherryVimto]

Hopefully someone who is more wise than me can answer these questions as my own research has not led me to the answers...

Is the crank sensor magnetic/hall or inductive ?

Is the idle control valve PWM (pulse width modulated) or stepper or on/off ?

How may times do the injectors pulse per engine cycle ?

Is the VCT solenoid PWM? If so, is it open or closed loop PWM ?

Thanks

 

[yippeekiay]

Crankshaft Position (CKP) Sensor
The crankshaft position sensor is an inductive pulse generator which scans 36-1 cast protrusions on the flywheel. Minus one means that one of the cast protrusions is missing and this gap is located at 90° before top dead centre. This gap is used by the powertrain control module as a reference for crankshaft position. The crankshaft position sensor sends an alternating voltage signal to the powertrain control module where it is converted and becomes the digital, profile ignition pick-up (PIP) signal.

Answer:- Inductive?

Idle Air Control (IAC) Valve
The idle air control valve is an electronically controlled solenoid valve which allows a flow of air to bypass the throttle plate. Engine speed can, therefore, be maintained irrespective of engine load. The idle air control valve is controlled by grounding pulses from the powertrain control module, the length of which determines the position of the valve.

Answer:- Pulse?

The two quotes above were copied from HERE FOR EXAMPLE but are also referenced later on with different measuring methods which is likely for different engine. All say the same relevant answer to the question you asked - I think :lol:

Fuel Injectors
The fuel injectors are activated sequentially by the powertrain control module which modifies fuelling by adjusting fuel injector opening times according to engine operating conditions.
HERE

Answer:- ??? - there may be info somewhere in that site manual but it's huge, so I could of missed it easily & couldn't find an efficient search.

The same goes for the VCT solenoid - it is referenced many times but couldn't find any specs or descriptions like the ones above. k:

I take no resposibility for any of this information - I just read this sh!t (for over an hour because I was bored) & then pasted it in here :lol:

 

[CherryVimto]

Thanks Yip, I had a feeling you would reply!

All info bookmarked, thank you. I certainly didn't expect anyone to spend hours reading random stuff just to answer!

I've also been able to find a little more information, some of it I found while looking for something else.

So, to compile all this together:

- Crank sensor is variable reluctance or 'VR'.
- Idle valve seems to be PWM.
- Injectors I assume pulses once but remain open longer depending on engine load etc.
- VCT I assume would be PWM. There is reference on the web saying that 'VVT' runs in open loop.. assuming Fords VCT is/works the same as VVT..

 

[yippeekiay]

I was bored - don't make a habit of it :lol:

 

[grogee]

I may be wrong but I suspect the FRP map fires injectors (a tiny amount) on the exhaust stroke, then the spark plug fires with the exhaust valve open to generate the overrun crackle. All this only under certain conditions eg throttle off, revs above a certain amount, engine up to temp.

I was thinking this because unless I'm wrong the Puma operates on 'lost spark' eg two plugs fire at once but only one is used for combustion.

Would be interested to hear from someone who knows more than me...

 

[CherryVimto]

Hi Grogee

'Lost spark' is referred to as 'wasted spark' and as you correctly state, 2 spark plugs fire at the same time.

Yes, the FRP map (which I run) does indeed do something to the fuelling to create a pop/crackle. More of a pop with my exhaust.
I can't 100% confirm what conditions need to be met for this pop/crackle to happen. I have always seen that it is more obvious when the exhaust (manifold?) is hot, therefore igniting the fuel that is injected while the exhaust valves are open. I say this because it will pop/crackle quicker in warmer weather than it does if the weather is cold(er).
I can confirm (on my car at least) that it isn't necessarily dependant on engine speed but is certainly dependant on throttle useage. I can easily drive along at any speed/revs and 'blip' the accelerator to make it pop/crackle. It is certainly more obvious within the higher rev range as anything up towards 6k will make it pop/crackle like crazy!

*I only assume that the injected fuel ignites when it hits the hot exhaust. I may be incorrect, I just stated that as any easy way to explain how my car behaves...

 

[grogee]

Thanks Cherry. Must admit I'm not sure what does the 'combusting' on the overrun - whether it's spark plug or nice hot manifold. Either sounds plausible.

 

[CherryVimto]

Thanks Cherry. Must admit I'm not sure what does the 'combusting' on the overrun - whether it's spark plug or nice hot manifold. Either sounds plausible.

I only assume it's the hot manifold because the exhaust valve would have to be open for the pop/crackle to exit the exhaust... and if the exhaust valve is open, the piston would be on an 'up' stroke. I doubt there would be combustion in a cylinder if the piston is travelling up at the same time.... just my theory! k: