[SOLVED] '91 Intermittent lack of power (1 Viewer)

[USMCDocJ]

Hey all.

My 80 has seemingly random lack of power. I'll drive 10 miles to a destination on road park and on the way back will have a lack of power going up, say an overpass. Or I'll get in for the first time of the day, drive 2-3 miles without issue then it lacks power.

The first time this happened was after a marathon off-road session from Mixtlàn to Mascóta, Mexico. It was damn demanding on the truck. No problems during, but as soon as we got to town on regular roads, it did it. Like top speed is 20ish on flat tarmac. Sometimes some back firing as well. Sometimes I'll go.weeka or months with no issue. I did a full tune up about 50k (miles) ago and baselined about 125k ago.

No CEL.
Truck was desmogged at time of baseline.

I replaced my AFM thinking that was it. (With a big box auto parts old Camry or celica or whatever I saw on here was a compatible unit because the 3fe one doesn't exist?)

Edit to add info.

 

[Mixelplix]

Listen, I know this sounds dumb, but I'm speaking from 1st hand experience. Are all your spark plug boots seated correctly? On mine, the rearmost plug wire is tight (cyl 6), and I drove my rig for literally years on 5 cylinders.

Other that that, I would check vacuum leaks, and your intake tube. The 3fe is very sensitive to unmetered air.

 

[USMCDocJ]

I'll check all those things. Thank you.

 

[Marco Lau]

Check battery connection and grounding....simple things first...

 

[SHREG]

Sometimes I'll go.weeka or months with no issue. I did a full tune up about 50k (miles) ago and baselined about 125k ago.

Bad gas, and I'm not talking gas station burrito. and its a 91 so the SOP is intermittent actual power. All joking aside, id suspect you're getting bad fuel on occasion given the frequency.

 

[USMCDocJ]

Turned out it was my pre-filter on my fuel pump... After removing and replacing the pump and sock with a new unit, the original pump tested good so I have a spare and have bought a new sock for it. Hopefully I'll know where it is in another 420+k miles when I need it.

 

[Outsane]

I should replace mine too good info

 

[jonheld]

Turned out it was my pre-filter on my fuel pump... After removing and replacing the pump and sock with a new unit, the original pump tested good so I have a spare and have bought a new sock for it. Hopefully I'll know where it is in another 420+k miles when I need it.

Typically a 100K mile service item on all 80 Series.

 

[USMCDocJ]

Typically a 100K mile service item on all 80 Series.

Haha. Yeah.... I was certainly deficient.