Well this has been going on for a while now with trying to get my PFC to work on my car that worked immediately on another and another standard PFC also wouldn't work on m ine.
So its believed to be the car.
To cut along story short, the car won't rev past 1800rpm. I believe the car is running so rich the car stops igniting the mix past that point. It used to rev to around 2500 but since I've re-done all my earths all over the car and put in a few new earth straps its dropped.
On a positive, the standard ECU is running sweeter than ever and I've taken another 200rpm off my idle. The car walked the emissions test on its MOT a month or so ago so there is nothing fundamentally wrong.
After satisfying myself that the MAF, plugs, coil, leads, ignition amplifier, TPS, water temp and most of the loom are okay I looked towards the injectors.
I've put a scope on the earth of the injectors at the ECU and watched the pulse on the standard ECU at the PFC. At first I could see at idle the PFC was putting in 3ms of fuel when the standard ECU was about 2ms. When I acclerate gently, this value on the PFC goes to 4ms whilst on standard it changes very little. So the car is running rich (the black spark plugs and petrol exhaust fumes also hint at this :roll: )
The resistor pack gives all the correct readings when tested and has no dynamic parts so I believe this to be fine too.
Today I swapped the injectors for the 700cc's I have and changed their settings to some off here. The same thing happened, as soon as you acclerate, the engine stutters. When I watch the signal, Cylinders 1 and 2 respond normally but the signal from 3 loses its (trigger) signal on the scope so I can't tell what it is doing at the point of misfiring. On the other injectors, the pulse just extends on the scope past 5ms point and continues to inject as much fuel as it thinks is needed. Past a point though the engine just bangs and pops which isn't suprising when it has nearly 200% the fuel it really needs going into the cylinder.
I've hooked up my timing light to the leads to get a visual indication of what they were doing but on cylinder 3 again the light goes out when the misfire happens. Is this because it stops firing or the fact they're covered in petrol?
The only other bit of evidence is when I first fitted the PFC and some new iridium plugs, it didn't go well for a few minutes so I took them out and put them to the side to this day. 3 are fine, 1 is brown. This is why I thought injector 3 might have a problem but swapping them has made no difference.
That's a brief summary of the background as I could go on forever with all my findings but these are my next two leads that I can't test until a week today because I'm away on work.
1. Here is a good link on how to test injectors amongst other things if you browse around the site: http://www.picotech.com/auto/articles/electronic-fuel-injection.html
If you look at the voltage saturated scope I'm getting a similar pulse but the signal drops to 0.6V on the PFC rather than 0.5V on standard ECU. Does this matter? Do I need to Earth bond at the ECU as well as on the manifold?
2. My Lambda sensor is reading 0.2V (lean) that means either I've killed it over the weekend or there is a fault with how it talks to the PFC? I will need to check the lamda on the old ECU again to make sure but it would explain why the car keeps chucking in too much fuel. It thinks its running lean so is always throwing in too much fuel, the car never gets an opportunity to run stoich. How can a Lambda not communicate with the PFC? Like I say, I'll have to check this out. I notice the Lambda uses a different Earth that I have already cleaned etc but I will double check.
The whole thing is a little bit chiken and egg, and the more you test, the more the plugs get covered in petrol and carbon so the less well it works. At the start of the weekend I bought some more plugs as the last ones got so bad the PFC couldn't start and would barely run at all. Because of the injector pulse widths, I believe any sparking problems are down to the overfueling first though and any spark failure is a secondary affect.
If there are any generous R owners in the North West, I wouldn't mind swapping the PFC with a standard ECU in my car and vice versa to prove again what RC had already done and double check the PFC ECU is still working.
Aside from that, I'll keep plugging away when I get back from work but would appreciate any ideas.
....and yes, that e-manage option is looking very tempting.
Cheers,
Jim
So its believed to be the car.
To cut along story short, the car won't rev past 1800rpm. I believe the car is running so rich the car stops igniting the mix past that point. It used to rev to around 2500 but since I've re-done all my earths all over the car and put in a few new earth straps its dropped.
On a positive, the standard ECU is running sweeter than ever and I've taken another 200rpm off my idle. The car walked the emissions test on its MOT a month or so ago so there is nothing fundamentally wrong.
After satisfying myself that the MAF, plugs, coil, leads, ignition amplifier, TPS, water temp and most of the loom are okay I looked towards the injectors.
I've put a scope on the earth of the injectors at the ECU and watched the pulse on the standard ECU at the PFC. At first I could see at idle the PFC was putting in 3ms of fuel when the standard ECU was about 2ms. When I acclerate gently, this value on the PFC goes to 4ms whilst on standard it changes very little. So the car is running rich (the black spark plugs and petrol exhaust fumes also hint at this :roll: )
The resistor pack gives all the correct readings when tested and has no dynamic parts so I believe this to be fine too.
Today I swapped the injectors for the 700cc's I have and changed their settings to some off here. The same thing happened, as soon as you acclerate, the engine stutters. When I watch the signal, Cylinders 1 and 2 respond normally but the signal from 3 loses its (trigger) signal on the scope so I can't tell what it is doing at the point of misfiring. On the other injectors, the pulse just extends on the scope past 5ms point and continues to inject as much fuel as it thinks is needed. Past a point though the engine just bangs and pops which isn't suprising when it has nearly 200% the fuel it really needs going into the cylinder.
I've hooked up my timing light to the leads to get a visual indication of what they were doing but on cylinder 3 again the light goes out when the misfire happens. Is this because it stops firing or the fact they're covered in petrol?
The only other bit of evidence is when I first fitted the PFC and some new iridium plugs, it didn't go well for a few minutes so I took them out and put them to the side to this day. 3 are fine, 1 is brown. This is why I thought injector 3 might have a problem but swapping them has made no difference.
That's a brief summary of the background as I could go on forever with all my findings but these are my next two leads that I can't test until a week today because I'm away on work.
1. Here is a good link on how to test injectors amongst other things if you browse around the site: http://www.picotech.com/auto/articles/electronic-fuel-injection.html
If you look at the voltage saturated scope I'm getting a similar pulse but the signal drops to 0.6V on the PFC rather than 0.5V on standard ECU. Does this matter? Do I need to Earth bond at the ECU as well as on the manifold?
2. My Lambda sensor is reading 0.2V (lean) that means either I've killed it over the weekend or there is a fault with how it talks to the PFC? I will need to check the lamda on the old ECU again to make sure but it would explain why the car keeps chucking in too much fuel. It thinks its running lean so is always throwing in too much fuel, the car never gets an opportunity to run stoich. How can a Lambda not communicate with the PFC? Like I say, I'll have to check this out. I notice the Lambda uses a different Earth that I have already cleaned etc but I will double check.
The whole thing is a little bit chiken and egg, and the more you test, the more the plugs get covered in petrol and carbon so the less well it works. At the start of the weekend I bought some more plugs as the last ones got so bad the PFC couldn't start and would barely run at all. Because of the injector pulse widths, I believe any sparking problems are down to the overfueling first though and any spark failure is a secondary affect.
If there are any generous R owners in the North West, I wouldn't mind swapping the PFC with a standard ECU in my car and vice versa to prove again what RC had already done and double check the PFC ECU is still working.
Aside from that, I'll keep plugging away when I get back from work but would appreciate any ideas.
....and yes, that e-manage option is looking very tempting.
Cheers,
Jim
but I will keep you informed and say how I get on.