Could really use some help

[gc73]

I assume its a bog and not a misfire. it loose all power and makes no combustion noise at all. sometimes it has power at WOT and sometimes not. might be able to go WOT 1st time and get moving might have to pump the throttle a dozen times and get RPM's up before it does anything but suck air. The only reliable time the engine has power is at high revs 3k-4500. Also you may be leaving you foot in same spot and the motor will go from bogging to revving to bogging every other second then come out of it totally and rev on up to 3500 leaving you foot and throttle in exactly same position.

I pulled the injector and looked at screens... nothing noticeable. I hosed the screens with some brake cleaner and put it back together. No change. One thing i did notice in relation to FPR was that the vac line to it didn't seem to have much if any vac... though i was able to spray some solvent through the metal elbow that comes off the throttle body and verified that the spray came through. Still didnt seem like much vac if any coming through at idle.

I also pulled all spark plugs. all except 1 were a tan/creme color and the one that wasnt was the far back plug (closest to firewall) and it was only slightly darker. When i have pulled the IAT in the past it seemed to be very wet and smell stronlgy of gas!

I thought about trying to give it just a very small shot of carb/choke cleaner or something similar when its doing what im calling the bog to see if that causes the motor to come out of the bog. in my mind that would prove/disprove lack of fuel, right?

Again thanks again for all the help, i am at my wits end with this thing.

if not misfiring, then check fuel pressure.
given all this parts changed or checked.
the one thing a good engine with good EFI needs first is fuel pressure.
and is not monitored by the ECU.

and the 10micron injector screens, the single injector comes out, did you inspect this? and see them? (bad fuel in the past can pack and injector, its 4times smaller media sizes than the filter.
i need to know when it has power and not.
the engine,power.
does engine have full power WOT>?? or only has power lose at other times, if its really bogging , not misfiring, then that is low fuel pressure , injector clogged.
or the map is dead. tool.. The map is the key sensor on all 8V .
the map sets the demand for fuel.
then the injector injects based off the map,, the ecu use the map to compute AIR FLOW in to the engine.
if the injector is ok then FUEL pressure is next. Fuel pressure can be low, with clogged filter, weak pump or FPR that sticks open, we measure pressure, and let fact tell us what is wrong.
not parts changed, ever, seen many bad new parts, I have.

the correct pressure running is 34 to 41 psi....
it's highest (pressure) at low altitude, to over come , normal air pressure. (1bar at sea-level.) this is the job of the FPR , doing that. it is for ALTITUDE.
as you go higher, up a mountain the fuel pressure drops , in direct proportion to the air pressure on your head. 1 for 1 ratio drop.

the FPR scale is on my FPR page.



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