I have been having some problems with my Honda Prelude having hesitation problems in vtec. The problem does not boost related (in terms of psi) and also now might not appear to be an ignition problem. I am running a built f20b block with an h22a4 head in a 92 prelude (using f20b/type-s cams). The setup now has a complete stock internal coil Obd1 ignition, ngk 8's and msd wires. I have datalogged two runs that were made: one with vtec at 4500 and one with vtec at 6500 (reving the car to 6k in each case).

The Hondata maps used were identical except VTEC switchover point. It appears on the graphs that rpm, map and duty cycle are stepped or choppy on the 1st run...which might be causing the hesitation (or are a result of it).

1st run - 4500vtec with hesistation/sputter at 5k+. Never passes 0.5-0.6bar for boost.
http://homepages.ucalgary.ca/~...1.rec



2nd run - 6500vtec (completely clean till at least 6k). Has been repeated up to 1bar.
http://homepages.ucalgary.ca/~...v.rec





Anyone ideas would be greatly appreciated. Please !!!

 

It was a issue with my wideband sensor that caused a fuel discrepancy...fuel removed and it is good now.