i have a 99 civic si with the following mods: aem intake, dc headers, exhaust, complete pulley set, web cams with titanium springs and retainers, integra type-r pistons. my problem is when vtec kicks in it doesn't really do much. i've checked the vtec solenoid and it is in good shape also replaced the map sensor. timing is good. fuel is also doing good. the valve clearances are within spec as well. i was thinking maybe oil pressure? one weird thing is every now and then, the vtec will kick in really hard and make an enormous difference, but 95% of the time it just makes noise and doesn't do much. any help would be great. thanks alot.

 

https://honda-tech.com/zerothread?id=164863

 

one thing i noticed from reading that thread you linked me to is my speedometer doesn't exactly work right. it's off by 5-10mph. my tach also doesnt work very well. the guy who owned the car before me took the entire pin out and tried to plug it back in. could this be a factor??????

 

as long as you are getting a signal to the spedo (meaning it works at all) it will work
I had a severe problem with my spedo for a while (bad connection on harness side of VSS)
vtec worked but my spedo would flutter up and down. meaning if i steped on the gas it would fly up to 80+mph then flutter down to normal speed while cruising.