if the fuel cooler screens clogs, the pressure will go higher, not lower.... I think your fuel pump is in the beginning of croak mode.

Jim

the pump at the cool fuel is the press pump boost pump on the other side... and your wrong anyway the only press that will build is between the pumps, at the fuel rail will still be low!!!!...... think about it


this is the flow diagram but does not show the boost pump which is just after the w/s filter

yes and if its clogged at the pump how do you get press after the pump????

no volume no press

you didnt have to remove your post or call me names I wasnt argueing, I was stating fact or debating, with someone with 35 yrs exp granted im a rookie thats only been doing this a few years like 25, by the way heres your post

Goodt,
I believe Buizilla is right, if the RETURN line screen (under the regulator - on the cooler) is clogged, you will have high fuel pressure at the fuel rail.

I agree with you that a clogged boost pump screen could cause low system pressure (usually under load), but as far as static (key-up) pressure and low load/idle, low volume (screen restricted) doesn't necessarily mean low pressure.

Dave

really not sure of what to take on this, kinda sounds like were going both directions, if someone wouldnt mind, (if this was your boat or motor) where would you start, i plan to change plugs and possibly plug wires.. what should i do about the fuel system, i would have to say that the fuel might be alittle on the old side, but it does seem to run fine from idle to about 4000 rpm's then it goes to crap, i have also replaced the fuel/water sep, as well as fuel filter (its a baja thing)? what should i do next? where i can i find this clogged fuel screen?

that does make sence but a I dont think there is a screen on the return( could be wrong) and for that screen to clog the srceens on both pumps would go first ...biggest problem Ive seen with the 496 fuel set up is debris from the tank clogging the boost pump screen and some getting trough to the press pump and destroying the vanes so you end up with two problems...never had any issues with the regulator or return lines ....doesnt mean it cant happen

never said I was always right and when im wrong ill be the first to admit it... if I am wrong then im wrong but I still dont go stomping off in a huff


thanks dave

I don't know who's right about the fuel system, but if you guys are gonna say "YOUR WRONG" then at least say/type it gramatically correct.


It should be "YOU'RE WRONG"

start at square one... it sounds like a fuel problem ( may not be but its a starting point)... hook fuel press gauge to fuel rail and take boat out watch the press though the rpm curve, check what it is when she starts to miss.... then if npf ( no problem found) you will need to have someone hook up the spx or rinda computer and check from there without reading the computer its tough to rule out most other factors.. I dont belive its a plug issue... and if its hitting guardian or flashing any codes the program will tell you.

first of all the scan tool will show faults-second of all it will show what percentage of guardian you are in because every problem associated with guardian will give you a different percentage of guardian.which will give you a percentage of wide open throttle-guardian is assoc with pcm 555 -older mefi units have power reduction not guardian-you need to first diag weather its a fuel problem or an injection problem-heck you could even have a problem with the injectors with all of the fuel additives -I dont even want to go there but start with the basics

when i say scan tool i mean mers new ddt too-I had to say that so I wouldnt get castrated here