power loss at full throttle

The place to discuss problems and routine maintenance questions and tips that are NOT specifically diesel-related.
flei
Regular Member
Posts: 4
Joined: Thu Oct 10, 2019 12:23 pm
Location: ks
Isuzu vehicle(s): 94 Pickup pickup 2.3

power loss at full throttle

Postby flei » Mon Dec 02, 2019 6:41 am

hi all, love this site. solved my melted air diverter valve. my 94 2.3 inline 4, 459549mi original on odo,is now losing power at full throttle. new plugs, plug wires,cap and rotor , fuel filter. added carb cleaner, sea foam, stp octane boost and heet.fuel tank is half full minimum, I even took cover off air cleaner for more air and still did it. mechanic said compression and fuel pump tests were fine. my commute is 80 mi round trip. its doing 65 mph then gags, speed dropping to 45, let off pedal then floor it, still dropping. pull over to road side sit for couple minutes, took off, 5 miles later gag, pulled over, 10 miles later, gag. got home. next day. filled up, was fine out bound and return to 79 mi, then, after my last stop lite, up my last slight incline, 30 mph gag to 20 mph, last .5 mi, got it home whew. bad gas, water? try 89 or premium? replaced carb in 2013 with oem rebuilt, still have my original, do not remember having issue, give it 1 last chance and swap it? if not parts car on this site? got a new hood too. wah, any ideas all? thx flei

Red Truck
Regular Member
Posts: 118
Joined: Wed Sep 18, 2013 7:10 pm
Location: Vader, WA

Re: power loss at full throttle

Postby Red Truck » Tue Dec 03, 2019 2:17 pm

The "recovery period" of sitting roadside for a period of time helps a little. Can you feel if the battery gets pretty hot (and spuges electrolyte)? Are the battery cells low, or dry (if you can tell)? Do things smell abnormally hot under the hood? I had a similar problem years ago; took me forever to figure out it was a bad alternator chip. Does it 'gag' when revving it in neutral, or only under load, at speed? Could it be the gas cap not sealing? or fuel tank vent hosing (cannister/purge assembly) deteriorated? And are there really close to 460 thousand miles on it? Pretty good!
'87 Isuzu pickup 2.3 gas, 5spd, 4WD

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puttputtinpup
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Posts: 10814
Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: power loss at full throttle

Postby puttputtinpup » Tue Dec 03, 2019 2:58 pm

same results with a full tank of gas? Tank not venting? Loosen gas cap and try it. Rusted pickup tube in tank? Clogged fuel filter?
Secondary throttle not opening as they should?

flei
Regular Member
Posts: 4
Joined: Thu Oct 10, 2019 12:23 pm
Location: ks
Isuzu vehicle(s): 94 Pickup pickup 2.3

Re: power loss at full throttle

Postby flei » Fri Dec 06, 2019 2:32 pm

yes puttputtinpup and red truck; yep 460000 miles and counting... will try all your suggestions and we shall see. goal is to get to the big 50! thx flei