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The 1.5A current rating of the 4427 is only an 'instantaneous rating' its only intended to provide the initial charge for the gate capacitance on a MOSFET for a period of nano-seconds, the continuous current rating is something like 200mA, I don't remember if they have over-temperature protection bu...

Most OEM ignition chips that I've seen have been protected, for between 350V to 450V. Perhaps larger coils instead of CDI pencils have a higher kick back. Yes usually around 400V to 450V clamping for an Ignition IGBT, that sets the maximum voltage that can be seen in the high tension side. I've not...

The 4427 may not have enough current drive - its is a Mosfet pre-driver, is there any specific reason why you are not using a MOSFET? You should probably have a current limiting resistor in the base as well to protect the driver from over-current. What are your resistor values? do you have the switc...

Most (all?) of the larger Powertrain processors have configurable pins on the microcontroller which allows functions to be moved around but how do you add signal conditioning and protection? the requirements for input and output and for analogue and digital are different.

mobyfab wrote:it really looks like nothing more than a workaround to get stuff done with limited cpu power

No there is no shortage of CPU power, OEM code is very efficient and scheduling the second event is trivial.

Ultimately it is about a more consistent fuel delivery, a 1us error on a 10ms pulse has far more effect then a 1us error on a 20ms pulse. OEM ECUs are far more complex than an aftermarket and its all aimed at extracting the most exact fuelling, aftermarket ECUs are greatly simplified, there are very...

Most aftermarket EFIs add the enrichment it to the primary pulse but that means extending the primary pulse which is what you want to avoid, particularly if you have stock hardware. They still have to do the maths, the reported injector PW is the sum of the two, you need to access the proprietary da...

This one is from a later model with a 16-bit ECU with a TPU running custom Denso code:



Technically is doesn't switch to batch injection but instead it adds a second pulse a short period after the main pulse.

With this strategy you have longer injector pulses at low load, any jitter in timing is reduced because its a percentage of the pulse length . At higher loads its less important because economy and emissions are less of an issue. As well as the timing issue as soon as the injector opens the pressure...

One smaller injector with two pulses is the same as one larger injector with one long pulse put you can get better accuracy under lighter loads such as at idle because any jitter on the injector pulse has less effect. On the MPI Suzukis the second pulse gives an injector strategy like batch injectio...

All the ECUs that I have worked on use this method, the second pulse adds the high load enrichment. Shorter pulses allow smaller injectors which give better fuelling under low loads. The fuel pressure is more stable as well, although that is partially offset by smaller, cheaper fuel rails, some Suzu...

mobyfab wrote:I need it for the knock sensor (sampling at 115kHz), but in this case the GBWP is more than sufficient indeed.

What is the bandwidth of the ADC?

Temperature sensors and Vbatt under even remotely normal conditions should not get close to the rails. The only "normal" sensors where I could see us getting close would be TPS, MAP and wideband EGO. So far I have not seen any evidence that getting close to the rails is an issue with stan...

rail-to-rail isn't usually needed because most sensors won't go that close to the rails, anything near to rail is generally flagged as short-circuit or open-circuit. For digital inputs you should really be using comparators, those are usually open-collector so the output can be pulled up whatever vo...

Problems with the LM1815 are usually down to poor PCB layout, insufficient decoupling or too much current into the inputs.

You need to study the circuitry as well, problems with VR sensor interfaces are usually down to poor PCB layout, insufficient decoupling or just putting too much current into the inputs. I've seen some terrible analysis of theses chips, including one that was done on a breadboard! What speed were th...

nighthunter wrote: By the way do not try to use LM1815 for VRs.

Why not? they were used in many ECUs.

Which ECU do you have? the early JDM models were different to the UK models though I believe that the connector pin-out is very similar.

Hi yes I found the online store, but the shipping is very expensive and then I believe it will need tax and duty paying for imports. Im wondering if I can get 10 made up by a UK based PCB firm and supply them via this website. I will looking it. You'd need to pay VAT at 20% plus a handling charge w...

I'm fairly confident Bosch actually gets ST to make their ICs too. Bosch have their own fab. I've used Ignition IGBTs with cheap comparator circuits to monitor current on a couple ECUs but mostly the igniters have been built into the coils. The integrated drivers will work OK, the semiconductor man...

kb1gtt wrote: I'm kind of dream of little boxes that you connect to the analog input sensor or digital outputs all connected with a digital bus, perhaps CAN or optical.

The SENT protocol is designed for interfacing sensors to ECUs.

On the 24x external crank, when I was digging in code, seemed like it was only used below 2000rpm for better resolution, then the ecu would switch to internal 7x crank. Gm was pretty funny about that. I could dig around to find the signal pattern for the 24x, but I may not use it if it can't go all...

I have a PCB, the CJ125 and the micro board, can I get the firmware please?

I've done some C++ development, mostly Borland but I've done a little MS Visual C++, its what I intend to use for future projects. I've dabbled with JSON for HTML and Android. I've used TunerPro for diagnostics and live tuning previously. I'd be interested in seeing how well EMStudio compares.

Is there any documentation on how to write a plug in?

gm ecu 40 pids/s is only so fast That's pretty quick for 'OBD2' if you follow the specification then something like 8.5 PIDs/sec is the maximum, I've done tests with a BT ELM and I was getting 4 PIDs/sec - its quite useless for any kind of tuning. RusEFI has a CANBus link that could run at 1Mb; 11-...

It would be preferable to inject 1&4 and 2&3 to keep fuelling identical between cylinders, it may not make any difference but it could mean that there is uneven fuelling - it will depend on the cam timing. I would hope that its a mistake on the wiring diagram. The OEM ECUs that I have worked...

DaWaN wrote: The throttle position sensor has two wipers if I am not mistaken: this is to accurately measure throttle position in low engine loads.

Is that not a TPS wiper and an idle switch?

http://rusefi.com/forum/download/file.php?id=2378 There are some bad solder joints there - the solder hasn't flowed through the conductors so the wire is only soldered on the outside edges, you may just need to reflow those joints. I would think that the problem was caused by the wires not being pr...

Has the trace fractured at the pad? it is a thin trace and it is not thickened before it joins to reduce stress.