I've had problems with hesitation at 1500-3000rpm. I've replaced all I can, plugs/oemplugwires/5wireNTK sensor. Still running into issues.
I purchased this car a month ago, had check engine lights for o2 etc. Finally figured out that the ECU that was on the car was a p72 ecu and not p07. I have a 92 california VX. I purchased a federal a07 ecu, all went well with the check engine light, but now its hesitating.
Timing seems to be off I've relined and relined. Im thinking its either the timing belt or head/cam gear is not the vx stock head. My cam gear has a pm3b stamped on it. From what I could search online, this might be for all the other models except vx? Also, what are the differences between si/vx head? what are some things I could tell if it's a vx hear or si head?
The VX head and intake manifold will have P07 on it, just like the ECU. There are also some big visual cues, like an ultra-small throttle body. I'm not sure about the cam gear but I'm willing to bet that it's the same as the Z6. The intake manifold has EGR on it. The valvetrain is unmistakable. If it has roller rockers, it's a Z1. If it's VTEC with no roller rockers, then it's a Z6 or equivalent. Unless of course it's OBD2.
VX's are very unforgiving to vacuum leaks. Any small amount of unmetered air will push the mixture too lean and you get hesitation and lean misfires. Car is 15 years old. Don't wait for the hoses to crumble to pieces. Replace all the vacuum lines. Replace the gaskets if anything has ever been taken apart.
Make sure those are the right parts. Most places will give you DX parts for your VX.