1HZ-T and 1HDT tuning for beginners? (1 Viewer)

[BreckenridgeCruiser]

Funny enough... Looking at the picture, it looks like I may have been getting into the fuel cut pretty hard... I couldn't see it well in person due to reflections and such. I will drive it and see if it seems weaker and start adding back tension if it seems like it's losing the top end.

You may need to zoom in to see the mark well.

 

[KiwiDingo]

Drive it without the pin in for a test and you'll no what the full potential is of your current main fuel screw setting. It's actually one of the first things I do when tuning. Set the max fueling first then when I'm happy I then starting sorting out the off boost/ during spool fueling with the aneroid pin grind, preload and shim adjustments.

 

[BreckenridgeCruiser]

Samsonite! I was way off!!

So I guess I was not as scientific as I was hoping to be and had to pay for it with my bike pump today. After looking at the above picture that clearly shows the pin travelling up the fuel cut ramp, I decided to use the bike pump setup to test pin travel.

I won't bore you with the process and details, but after MANY clicks to tighten the preload on the spring back up I got it back to full travel and stopping at the full fuel section at around 15-17psi. My bike pump is not super accurate so I will drive it like this for a bit and check the travel again after a few days and a good solid hill climb or two.

So the lesson learned is once you take the shim out, test again before adjusting the preload! I lessened the preload and misread the marks (didn't see that it was cutting fuel) so didn't see that I needed to increase and not decrease the preload. After about 5 or 6 rounds of pressurizing and adjustments with the bike pump, I have it dialed back in and the truck pulls up hills very well now.

The next few days will be fine tuning the spring load and then watching EGTs to see if I want or need to adjust the main fuel screw (still at stock settings).

I will give it a lap around the block pinless at some point. Do I disconnect the line to the boost comp with the pin out and block it? I assume I don't want to pressurize the pump. Sorry for the dumb questions but better safe than sorry.