I asked the witch doctor (bout' high pressure)

[Guest jjohart]

I asked the witch doctor, as in local garage/used car salesman if my car's hesitation might be from an old OEM fuel pumps' inability to keep up(1983 280ZXT with I/C, CAI, adjustable FPR),...and he said:

The main purpose of upgrading the fuel pump would be if the factory set-up couldn't meet the demand of upgraded injectors, etc.

As long as the fuel pressure doesn't drop under high-boost, high rpm conditions, then changing to a high-volume / high-pressure pump should have no effect.

IS this correct? I have stock plugs and reasonably new stock injector/rail, etc (the adjustable FPR was a Bosch from Overboost.com-set by this mechanic to 8psi above stock, to no change), but in my mind, I'm wondering why it ISN'T possible that what I've got is a fuel pump that is lazy and slow when the car isn't fully warm=or its below freezing, as of late, or the throttle isn't pushed wide open, but once I PUSH WOT or get the car warmed up enough, the light throttle applications normalize=pump works appropriately?

Am I totally clueless-yup!

Thanks

John-Natick, MA

[Clifton]

This is correct. If in doubt just T into the feed line and run a cheap gauge to your windsheild ofr a quick test. I have done many times when I know it's lean but not sure if it's the injectors or pump that are maxed out.