Hey Guys. I have been working with Mark for a few months, he burned me a starter chip, and I have to say he has done so much for me with helping me get my truck dialed in, he should really charge more because he offers a service that is priceless. He really is awesome to deal with and I'm so glad I came here after getting screwed by TBI Chips.com. Before Mark went in for his first surgery I talked with him about some issues I was having and I wanted to try different injectors and run some logs, and I was going to send them over to him for so he can check them out and see how it's going. I was hoping maybe you guys could give me some feedback on what you see or think.
I am not burning my own chips, I was going to at first but after talking with Mark I decided to let him to it for me. I am on a starter chip right now, and the truck runs and drives good. I am trying to get a good setup that doesn't have the smaller injectors maxed out. I am very engine savvy and have been building engines for years, but I am not so super with this TBI stuff. My question I have is, what is better, larger injectors with less pressure, or smaller injectors with more pressure. So, on Mark's starter chip, I was running 80lb injectors with 14.7psi fuel pressure. The truck seemed pretty good but just never felt quite right. I talked with Mark about running 61lb injectors with more pressure and run some logs to see what it looks like. So I started by making an adjustable regulator which has been quite interesting, and I ran some logs with varying fuel pressure.
My 80lb injectors are new Napa injectors which I think they may be junk. The engine never seemed real smooth. So I wanted to try my GM 5.7 injectors with more pressure. I cold never get the pressure over 18-19 psi without it being very finicky. I learned the spring was pretty much coil bound when trying to adjust it higher than that, so I took found that a spring from inside a wheel cylinder feels about half as strong as the stock pressure spring and fits inside it without and issues. So I doubled the springs up and can easily get my pressure deep into the 20 psi range.
Run 1 was too much pressure, before I double the springs and I was coil binding the stock spring. It was 26 PSI
Run 2 was at 21 PSI
Run 3 was at 22 PSI
Run 9 was one of the last logs I ran with the big injectors on 14.7 PSI
I noticed the engine feels smoother and seems to run a lot better over all with the smaller injectors, and again, this may be because I have junk 80lb injectors. I was hoping to find a set to have sent out and cleaned and flowed but I haven't found a set yet, and I am hoping the smaller injectors with more pressure will be fine. Is there a way to tell how hard the injectors are working? I was basing it where the BLM was going, it seems close to where it was with the big injectors.
Thanks in advance to anyone who responds, your feed back is really appreciated.
I guess you may want to know the specs:
95 K1500 5.7
355ci, zero decked block (.039 quench)
flat top 2v pistons (9.6:1 compression)
72cc dart 165cc heads
isky roller cam 211252/257 w/1.6 roller rockers
Edelbrock 3704 intake
stock manifolds, dynomax cat back
Thanks,
Barry
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