This may be a little bit of a read, but I'm out of options...

Started building this setup last year.

Original setup is as follows-

Stock Sleeve Block 81.5mm Bore (9.5:1 Comp)
Eagle Rods
JE Pistons
Stock crank
Main Studs
Head Studs
B16 Head
Stock Valves
GSR cams
Supertech Valve springs and retainers


Go Autoworks Street Kit w/ Turbonetics T3/T04b
Walbro 255lph fuel pump
RC 750cc injectors
Hondata S300

Car was tuned by Jim @ Motorvations to 321whp and ran like a dream. After I got home my turbo charger crapped out and the car went back down for warranty work from Turbonetics. After it was re-assembled it made its last and only good street pull... Sleeve gave out! How awesome right!?

Now I have replaced the bottom end with a GE sleeved bottom end and it fires and runs with every key turn. Only major problem that is occurring, every time you give it throttle it IMMEDIATELY leans out (16 or higher). That is under 25% throttle. Have tried running it SLOWLY up the RPMs to keep it safe and see if the problem exists in higher RPMs and it does.

Troublshooting so far:

New Fuel Filter
Inspection of all fuel lines
Inspection of fuel rail and injector screens
Inspection of fuel pump
Tried different FPR (both are stock Honda)
Inspected fuel line from filter to rail
Inspected O-rings

Next step:

Install fuel pressure gauge so that it can be seen from inside the car, to make sure that the issue lays in the fuel system. The only thing this is going to do, is tell us we are chasing the correct issue.

What I need are past experiences, advice, or an idea about where my issue could be. Basically looking for fresh opinions from KNOWLEDGEABLE people.

Thanks for any help and PM if necessary.

-Josh

 

Sounds like you need to tune it.

 

Sounds like the car need to be retuned. Whenever you change something in the motor you need to tune for it.

 

reeeeeeee-ttttttuuuuuunnnnneeeee

 

Sounds like you been dealing with a bad tune the whole time...

 

Your troublseshooting skills/ideas are lacking.

Also, what bore size did you go to the second time? Need more information. What you gave is all fluff.

Most certainly it is/was your tune.

 

Cylinder bore is still @ 81.5mm and compression is going to be closer to 9.0:1. I am definitely going back for another tune but I was under the impression there wouldn't be that much to worry about from simply lowering compression.

I have changed bottom ends in the past (from stock sleeve to aftermarket sleeve) and was able to drive the car with no issues (on the previous tune). Car shouldn't be getting that lean in vacuum.

Well I guess back to the drawing board.

Thanks fellas.

Just for clarification, the tune was spot on. Car ran perfect on the dyno and drove home with zero issues. All issues started after it was reassembled with the bottom end. It was driven hard a few times, but we are thinking that bad gas may have been the cause of the original failed bottom end.

 

My knowledge is questionable..but I would like to enter the discussion if I may?
When u say ran fine home, were u able to monitor afr at that time?
I assume so. If it was ok then..then, ok.
u mention bad gas, as in low octane or old?
If it sat for awhile during rebuild, maybe you should have the injectors flow tested and cleaned...local guy does it here, maybe u have someone where you live so u dont have to send them in. maybe the screens look ok but mechanically malfunctioning?
Do u have a gauge now, is static pressure normal?
Please post up findings/resolution, people sometimes abandon their troubleshooting threads and ruin my archival reading pleasure.
I search alot.

 

You rebuilt the bottom end after having a sleeve go at only 320whp. Sounds like a bad tune.

 

Showed this thread to Johnny at the track last night and he feels that you have been dealing with a bad tune the entire time.

Take the car to him and let him look at it.

 

I agree the tune needs a second look for sure. However, be sure you don't have any major exhaust leaks upstream from your wideband.

 

How old are those RC 750's? I've seen a lot of people have problems with them in the past because they are just a 450cc injector with a larger pintle and valve. Problems usually result from running them above their rated fuel pressure which I believe is about 43.5 psi.

Not saying that's the problem, but I wouldn't rule it out as a possibility and just blame the tune.

 

The injectors have about 1500 miles on them, max.

Thanks for the help.