Scotty Kilmer said he has a tool to see fuel trim per fuel injector. That's
incredible and I think my ECU has maxed out adjustment if they still
can't run even. Or the ECU is just not sensitive enough to get the fuel injector's timing any closer to being right.
I'm on my 3rd change of fuel injectors. This only covers a fraction of the times I had to pull the system a part because fuel leaks kept developing above the fuel injectors. With how my fuel injectors sit on my engine this gives an amazing opportunity for them to sit in fuel. I don't think they're designed to do that because they failed right and left until I got better at setting them up without leaks. Part of the posts that my fuel rail secure to are plastic and damaged so I think they were the cause of most of my frustration. It's easy to get the fuel rail to tight with this setup on my 1999 Chevy Prizm - same as a Toyota Corolla.
I developed an interesting problem towards, hopefully the end, of this project that has had me under my hood for hours at a time repeatedly for days and going into weeks.
At this point, I can do the job of changing them out or a certain faulty one out in 10-30 minutes. The 30 part was added just in case of pride, but I've really gotten much faster.
When the remanufacturer wanted me to switch fuel
injector 1 and 2 I found myself to be very upset. Sure, I had misfires at every startup on cylinder no. 1
and sometimes I had a P0300 as well, but this was less of a misfire to do no flow, and more likely just incorrect flow.
When I switched 1 and 2 the problem would have disappeared without my laser thermometer.
Let me explain.
Cylinders
2 and 3 fire one after another just like 1 and 4 fire one after the other. Basically,
switching two injectors got rid of a misfire as each cylinder firing order set has a lean and rich injector. The O2 sensor sees the pulse on exhaust
of each group of time of cylinders next to each other in firing order and everything looks on target. Virtually no fuel trim, except at idle, but I'm sure that's a separate issue.
I
believed that my original set of fuel injectors were actually much more
efficient because the leaking fuel injector actually caused the rest of the
engine to run lean.
When they sent me a set of fuel injectors that ran
perfectly even all the laser temps were the same per cylinder and fuel mileage was
down from 43 to 35....or way worse if you include that over some days
all but one failed on the first set, but that's a bigger more frustrating story....
So, with how long winded I am, I only could
ask Scotty Kilmer one tiny bit of all this on the live event, but what I'm
going to do before I install yet a 3rd set of injectors is widen the
spark plug gap on the two cylinders that are getting more fuel.
You see, I learned from my ACE studying today that the spark line can indicate a problem in a cylinder. The shorter the spark line, the shorter the secondary resistance should be, however, when spark is normal, it can also be a way to detect a greater fuel to air mixtures.
More fuel equals less resistance to spark. So, I'm thinking of checking if I can change my richer cylinders 3 and 4 to .046 spark plug gap instead of .044. This would raise resistance, get a longer burning of the richer fuel, and I'd LOVE to see the car's miles per gallon results on that!
All I could fit in to ask Scotty Kilmer on the live event today on YouTube was if I should keep plugging on with my current ones, I mean, I have better MPG because the O2 is seeing stoichemetric...yet it's due to a bit of a trick ;) lol. He guessed right away what I didn't have space to say that they were remanufactured and that they'll never be perfect unless I want to buy new ones...
To check out my question from this mornings live event check here: Scotty Kilmer Live Event He does this about weekly, except that his older son had a wedding so this was the first event in a few weeks.
....this is very tempting as my system is pretty stable and I have another miles per gallon experiment to run. :) If you want to check out the conversation that lead to the making of this article go to Scotty Kilmer's video on Gasoline and Your Car
12/21 update:
I've been running the 3rd set of warrantied injectors for about a week now. I was able to put my spark plug gap back to stock 0.044 inches. The trick with increasing the spark plug gap where I had hotter cylinders due to more fuel did help. I almost got the temperatures even. The engine wasn't actually running even of course, but it was a lot better. So that's a trick that can help you get through a leaking injector...though in my case that fuel injector was less leaking and more just over spraying...I think ;).
10/11/2015
A year later, and now I'm making videos. See some knowledge I talk about here presented in video format!
by AutoBravado
