Injector Dead Time Voltage Correction

[@morphius2003]

Thank you for this video. I had the same idea, and did not know if it would work. Now i know it does. One more cheked box on my long list.🎉

[@westleyhurtgen4275]

This is definitely the most helpful video I've found on this subject. Any idea how one would go about getting this working with a factory engine harness in?

[@ryan_layne]

Glad you found it helpful… I would imagine you can do the exact same thing. Theres a power pin on the ecu and the injector harness can be bypassed

[@Juan-uh2gt]

Hey man, this is absolutely what i needed and actually am about to try this today. So i appreciate the video. I was curious if you could tell me what you connected your negative side to. I assume chassis ground but wanted to make sure before i messed something up.

[@ryan_layne]

Chassis ground but make sure your voltage drop is neglegible between chassis ground and ecu, and chassis ground and injectors. Otherwise they readings and correction will be incorrect.

[@MohawkMasters]

You wouldn't happen to know the injector characteristics settings for a 510cc 4g63t injector would you? I'm also using tunerstudio and also a speeduino board UA4C it's my first time setting a project car up and I'm all new to this.

[@ryan_layne]

I don't, sorry, but as demonstrated it is quite easy to intrinsically arrive at the correct values for these numbers. I am of the opinion that this is even better than knowing the theoretical characteristics of injectors. Unless the factory tests your specific injectors at your specific fuel pressure, etc, it will almost certainly be slightly wrong to use their numbers. If you instead use this method to determine your dead time, you will arrive at the precise correct number you need for consistent running on your car.

[@teadrinkingilluminati9173]

Great video but how do i measure deadtime at a set voltage?

[@ryan_layne]

@@teadrinkingilluminati9173 There are numerous methodologies, including getting a spec sheet from the manufacturer, which a google search will pull up. But the easiest way is to set engine to a fixed rpm, maybe 1500, and then change the number of squirts per cycle and adjust the dead time until the AFR does not change. So if normally you do 2 squirt per cycle then changing to 3 or 4 squirts should make no difference to AFR. But if it does, you know the dead time is wrong and throwing off the injector pulsewidth calculation. Adjust dead time while running until the AFR is stable at a couple different squirt counts.

[@tonyvtech25]

I HAVE A CONFUSION. THE INJECTORS I HAVE NOW THE DATA SAY OFFSET IS .055ms . DO I NEED TO ADD OR SUBTRACT THAT FROM THE CURRENT NUMBERS OR I NEED TO CHANGE THE CURRENT 1.280ms @ 14v WITH THIS .055ms. AND THEN INTERPOLATE OR SMOOTH THE TABLE AND START FROM THERE ?

[@ryan_layne]

@@tonyvtech25 Dead time is not the same as dead time voltage correction. If your injectors come with data specifying the dead time and voltage then set the base dead time to that value, then run through the procedure in the video to calculate correction. Set the table to have 0 correction at the voltage specified in the data. So for example if thats 0.055ms at 14v, then set your correction at 14v to 0 and then make everything in the correction table match the afr which shows at 14v. Then fix the rest of your tune fuel tables because those will now be wrong.

[@tonyvtech25]

@@ryan_layne THANK YOU

[@e34boat88]

so both ecu and injectors needs the voltage from rhe variable controller?

[@ryan_layne]

Yes, the ECU needs to see the injector voltage changing and apply its dead time adjustment curve.

[@ericw1617]

How did you get the voltage to the ECU was your bench powersupply supplying the ecu as well

[@ryan_layne]

ECU has a direct wire to the battery as is always recommended

[@ryan_layne]

I ran a wire from the power supply back to where the ECU connects to the battery and then that wire goes all the way back up to the ECU. I just did that because it was easier than trying to back probe directly into the ECU connector