Hi everyone
I'm after recommendations for a suitable Link ECU for the following problem.
I have a jaguar xjs v12 1988. Last year I bought an EFi kit from Mobeck based in Sweden (www.mobek.com) to upgrade from my old factory EFi system. The kit included a Maxxecu Street with distributorless conversion. The kit included injectors, leads, coil pack, trigger wheel, idle control valve etc...
Overall the kit works fine except I'm not happy with how the idle works, as it seems a little off, never working exactly how I want it to, with fluctuations that don't reflect the settings. However the car drives 1000 times better than with the old EFi system, so I didn't make to much of this.
However, I live in a hot country (Pakistan) and so I decided to swap out the visco fan with a high powered Mercedes unit (600W). Originally we bypassed the PWM controller of the fan, so it would work using one of the custom outputs as a FAN controller, with a simple trigger at a particular temperature, in this case 86C. However the fan would then come on at full speed, with a noticeable load blip on the car. The fan would quickly cool the car down and turn completely off, however then the car would quickly heat up and again and then fan would constantly be flipping between on and off. Although this works fine, I'm a little worried that this constant high load on the car will stress the alternator and electronics.
To this end I thought about using the fan's PWM controller so we could precisely control the fan speed. So there isn't the instant load hit on the car when the fan suddenly turns on at full speed and it just seems a more elegant solution. There is an option in the Maxxecu tuner to set the fan output to a PWM output, so thinking this would easily solve the problem we tried this. However in this mode the fan would work erratically, either full speed or rapidly cycling between on and off. We confirmed the frequency of the Mercedes fan, which is 10Hz, and also the duty cycle of operation, 10% off to 90% full speed. We even tested the fan in an actual Mercedes car and measured the frequency and duty cycle and they were spot on. When we measure the output from the Maxxecu, neither the Frequency nor the Duty Cycle is steady. In fact the duty cycle fluctuates widely. Interestingly, when we then checked the output for the idle control valve, that also wasn't steady! Maybe this explains the inconsistent idle! I contacted Maxxecu but their reply was that at a low frequency of 10Hz, there would be some fluctuations. I explained that when the duty cycle is set to 10%, it is fluctuating between 40% and 90%, which I regard as more than 'some' fluctuation. However just to check I set the frequency to 100Hz and still the duty cycle was all over the place. I think either the Maxxecu cannot handle PWM outputs or there is a fault in my particular ECU. Either-way, I'm not happy with their half hearted responses so have decided to find an alternative ECU.
So basically I need an ECU that can drive 12 cylinders (wasted spark acceptable) but also create steady PWM output. Sorry for the long message just wanted to explain my problem.
Thank you all.
Warm regards
