Random Loss of Power whie acclerating FZJ80

[brandonatx13]

I have a 93 land cruiser that I swear I done everything to make it run perfect but I keep getting a random loss of power while accelerating that goes away after a few seconds then might not come back for 20 mins or the next time I drive. Other than that it runs perfect with lots of power.

I done the following:
Plugs & wires
cap & rotor
all vac lines
IAC Valve Toyota
TPS Toyota
Bypass EGR
Bypass Pair
Cleaned Injectors & connectors
New NTK O2 Sensors
Put dielectric grease on all connections
Clean Throttle Body
PCV Valve
Denso fuel pump
Fuel Pressure regulator Toyota
Valve Cover Gasket & Spark Plug Tube Seals
NO CEL
Timing at a Perfect 3 BTDC with e1 & te1
Very Smooth Idle

I am thinking maybe the VAF Meter is just worn out? I took the cover off and cleaned it with electronics cleaner and resealed? Maybe computer or wiring? Ideas?

 

[Jason hansen]

Fusible links, wiring harness near egr pipe may be making intermittent contact causing a short.

 

[Notch]

Assuming it's a smooth drop in power, like a bogging feeling, I would suspect a fueling issue. If it's more of a sputtering thing check out ignition stuff first. It's much cheaper (and educational) to diagnose the problem rather than throwing parts at it.

For fuel the first thing I would do is put a temporary wideband air/fuel gauge in the exhaust as see what the AFRs look like when the power loss happens. That may lead you to a voltage drop at the pump, airflow meter, clogged filter, trash in pickup etc.. Diligently check for air leaks after the airflow meter all the way to the ports in the head.

If the AFRs look good I would watch timing when the power drops. Could be a timing signal problem, coil issue, wiring issue etc.

good luck!

 

[brandonatx13]

It's a very smooth drop in power, then when you step on the gas nothing, just downshifts and rpm's go up, let off the gas then step on it a few seconds later then power comes back, very random and intermittent. The only thing is notice is at idle the rpm gauge fluctuates up and down ever so slightly like + or - 50 rpm, but i don't feel the actual rpm's changing

 

[Notch]

It's not a slip in the transmission? Definitely check the wiring Jason mentioned along with your chassis and engine grounds that are exposed to water (interior sometimes! haha) or weather. Anything that moves or changes temperature is suspect if it's an electrical problem. Relays can be temperamental with heat and vibration too. Spark plugs were gapped correctly? Spark "blowing out" is often confused for a fueling issue when it's actually too big of a gap, too dense charge (rich) or weak iginition coil(s). You can diagnose this sometimes by closing the gap tighter than stock and if symptoms go away it could be a coil that tests fine but doesn't preform when hot.