Haven't been on here in awhile. Between working so much the past few months and getting disgusted with tuning progress I haven't made much time to play with the truck but I finally tore into it this past weekend. Short story, Dave W has been my tuner. The start up bin went better than expected, truck started and ran pretty well but rich. Did some data logs and sent them to him. Bin #2 showed seemed to show some mild improvements, but still rich. More data logs and on to Bin #3. Down hill, very rich, particularly at idle and low throttle, can smell the fuel in the exhaust. Cold start would barely idle and stall if you tried to give it gas. Only way I could get it to restart was to hold the throttle wide open. Quickly developed a bad miss. This past weekend I pulled the plugs and this is what I found.
Attachment 9997
These were brand new plugs with probably less than 100 miles on them, just some casual driving and data logging. Cyl #4 was wet and as you can see not carbon fouled. Ran a compression check and found to only have 55lbs on that cyl. Pulled the valve cover and found a broken intake rocker stud.
Attachment 9998
Pulled the #4 exhaust rocker arm and put some air to the cylinder, its leaking down, I think past the exhaust valve so it looks like I'll be pulling at least this head. As to why and when the stud broke is beyond me. I'm pretty sure those comp rockers are considered long slots and I couldn't see any evidence of the slot hitting the stud. I use Mr Gasket screw in studs. Are they worthwhile or should I replace them all?
Obviously I've got some mechanical issues to fix but let's get back to the tuning. I was hoping to get anywhere between 325-375 fwhp out of this build. I converted the fpr to adjustable by installing a screw in the base, still used the stock spring. I used the EP377 fuel pump. I installed a schraeder valve between the fuel filter and TB inlet. I was running 17-18 psi at start-up (as I'm sitting here typing this I'm thinking, hmm, maybe I should check to see if this is still where I'm at now) and I'm using cop car injectors cleaned and flow tested by Mr Injector in a 46mm bored throttle body from SRP performance. Am I pushing to much fuel for this build? Should I lower the fuel pressure or try to tune to it?
Problem during initial start-up, erratic high idle. IAC valve was apparently bad on rebuilt throttle body, replaced with the one off my original throttle body and problem went away. Any other throttle body issues I should be looking for?
Here are the start-up files that Dave gave me and the data logs that followed.
skip down a few posts
Looking for tuning help and using tuner pro RT.
Thx
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