Discussion and questions related to the course EFI Tuning Fundamentals
Today i finally completed the fuel system consisting of Bosch pump 044 in tank with 2 x Bosch 044 pumps in surge tank feeding 5 ID 1300x injectors (5 cylinder engine). The setup includes Fuel pressure regulator.
Being over eager to get the engine running i didn't change any fuel parameters thus the result was a no start condition, wet plugs and seems cylinders were flooded. (bore wash). I did manage to get it running for a short while (after some adjustments)however it was very rough and unsustainable. My question thus is what is a suitable minimum injector pw, injector main adjuster scaler pw. cold prime pw/cranking pw, injector dead time for ID1300x to get the engine started without fowling spark plugs.
This engine was running for 5 months on stock injectors without any issues.
My aim was to upgrade fuel system and then get it on a dyno for proper tuning.
Hope you guys can help.
You haven't mentioned what ECU you're tuning, however all of the relevant information for ID injectors is on their website. For an aftermarket ECU use the Slope & Offset vs Pressure data for your differential fuel pressure. They also have plug n play data for GM, Ford and a few other OE ECUs.
If you have an ECU with cranking enrichment that is pulse width based then the best starting point is by making a percentage correction to the tables based on the relative injector sizes. For example if you double the injector size then you'd halve the pulse width in these tables. That will get you close. Minimum pulse width for the ID1300 is listed at 0.125 ms
Hi Andre. Thanks for the response. The ECU in question is branded as 034 Stage IIC previously supplied by 034 Motorsport. I have installed the stock injectors and settings just to get the engine running again, everything is back to normal. I also done some refreshing on the course material and determined the flow rates are five times that of the stock injectors. Thus I have calculated the main PW scaler should be around 4.8ms to flow the same volume of fuel as the stock injector at a PW of 24ms. As you mentioned the cranking PW needs reduction as well, thus I will keep this in mind when eventually install the ID1300x2. Thanks for the help.