Exactly how sensitive is the UTEC knock sensor? Can it detect a rattle/noise from outside the motor and interpret it as knock? I normally run my water injection on/off functions through the spare solenoid on the UTEC, but I had to bleed the air out of it last week and for now I'm running it on a toggle switch. I don't drive my car too hard, and when I do its usually short sprints from a slow roll. I was on the interstate the other night and no one was around, so I flipped on the W/I, downshifted to 3rd, and floored it. The UTEC immediately detected knock and pulled timing. I thought perhaps I had boost creep, so I pulled over and turned the boost down, got back up to speed, floored it again with the same results. This was around 50 mph. I went from a 10mph roll up to 80 and the car was fine. My W/I pump is fairly noisy, if you flip it on at low speeds you can hear it running in the engine bay. Think there's any way the UTEC is picking it up or do I have other problems. I plan on taking some logs later tonight.

IMO your tune is suspect and you downshifting and getting on it is putting you into a much different load site than you were while in cruise.

Make sure you don't have a leak somewhere in your WI tubing going to the nozzle from the pump. I had a crack in the poly tubing that plumbs my water/meth to the IC, and it was spraying on the downpipe/turbo, so it would evaporate before I could ever find it. I finally had to disconnect the hose and run the pump to find the leak so I could see it spray and check the pressure. That little leak was causing a big pressure drop after the leak, and I wasn't getting all of the "boost juice" into the nozzle, and it was at a greatly decreased pressure. So the car knocked whenever the alcohol was sparying, becuase it was expecting the mixture and pressure it was tuned at, and wasn't getting it. So the car was knocking with good reason, and I couln't figure out why until I found the leak. No probs now. Check for leaks, and install a pressure gauge if you don't have one for you WI system. You can get a 4.99 100# water guage at you local True Value, and then screw it into a compression union, and then run the tubing into it, and then to the main WI tubing header. I am putting mine in tomorrow. Just so I know that the system is running right.

DP

I believe a lot of people consider the UTEC more sensitive than the stock ECU. If you look at many UTEC logs, see that the UTEC tends to correct for 1 and 2 counts while the ECU does not. Sometimes at least...

I suppose it could pick up pump noise if the pump were mounted with a very solid mounting bracket directly to the engine block. I would mount it on the chassis if it is on the block now and try again.

my utec's knock thresholds are set so close to the inherent mechanical noise that i can tell when i'm running a bit low on oil. i didn't believe it myself until it happened more than once.

the sensitivity is a user definable field, and absolutely SHOULD be tweaked towards more sensitive IMHO. i am running at least +10 over the basemap sensitivity. a friend with an ej257 and forged pistons is running about the same increase over "factory" thresholds.

ime, it is far better to falsely pick up a knock that wasn't really there than it is to miss one that actually happened.

ken

If you try to fix noise thinking it is knock, it may be like hitting your head against a brick wall. Pulling timing, adding fuel, and driving EGT up unnecessary.

At least for my car I believe the UTEC is more sensitive out of the box. Sometimes the stock ECU will pull timing when the UTEC does for knock, sometimes not. At least on my car I haven't seen any time where the ECU seems to pull timing but the UTEC does not record a knock or pull timing itself. Not saying it isn't possible, though.

I think I may end up trying to tune the sensitivity with a knock headset. That would probably be the preferrable technique.