Lack of Power

[83S154x4]

Got my 83 S15 4x4 with the 2.8 about 8 or 9 months ago. It is quite possibly the slowest thing on the planet. I'm pretty sure it's not the tranny (auto) because that runs just fine. It's missing a good chunk of the air intake, only got the metal part that attaches to the engine, no plastic, but i wouldn't think that would cause a huge decrease in power, right? Even with a new air filter, fresh oil and filter, and a clean carb, it's still pretty sluggish. i took the AC belt off to try and get more power, but didn't help much. chopped exhaust and slapped on a cherry bomb, but that didn't help either. replaced plugs and wires too. i'm thinking i may need to advance the ignition timing a hair, it tends to diesel a little bit after i drive it and kill the engine. Also, anybody know a good way to fix a leaky radiator? i've tried this putty and some liquid leak stopper, but no such luck. Heard a story about using pepper, but i'm not about to throw seasoning into my cooling system. I'm slowly running out of ideas here on the power issue, so lemme know what you think!

BTW, it's got about 140K on it, and it's got a 700r4 tranny.

[SH-60B]

Make sure the vacuum advance is working and the vacuum line is hooked up and not cracked/leaking.
Make sure the mechanical advance is working too, and the weights move freely, clean and lube them if they're sticky. Set the initial timing to the book and try that as a starting point.

[trixed]

i had just got mine fixed this weekend. we had adjusted the timing

[Datchevy2.8]

I didn't see you mention a fuel filter ( located on the carb), just a thought.

[83S154x4]

checked vacuum advance line, no leaks or holes there. i've been meaning to replace the fuel filter to the point where i have the filter in the cab, but seeing as how i've never owned a carb'd car before, i'm hesitant to attack it at the risk of ruining it.

[SH-60B]

Did you check the initial timing at least? It's 10 degrees BTDC with your automatic.

[Rustdaway]

Put a can or 2 of sea foam through it. If the top of the air filter isnt there and the carb was open a lot of things could of gone into the carb and ate up your valves. Power and 2.8 do not belong in the same sentence.

[83S154x4]

not the top of the air filter cover, the plastic bendy tube that goes to the outside of the truck to get cold air.

[spykrules_276]

Quote: Originally Posted by Rustdaway

Power and 2.8 do not belong in the same sentence.

HEY!!!!!!

[83S154x4]

UPDATE: Today i drove it back from work, about a 20 minute drive, highway speeds, and went inside, did my business, and about an hour later went to go take off. Started, died, pumped the gas pedal, started, idle was really low: approx 700-800 RPM. it tried to kill itself again, but i pumped more gas into it, kept idling low, but put it in gear and took off, no problems the rest of the day. I dunno if this helps, but i'm really thinking i'm gonna take another look at that fuel filter tomorrow.

[SH-60B]

My '83 had a heating grid under the carburator that gave me grief but only in the winter. Unplug it or take it completely out.

[SH-60B]

deleted

[chevymandill]

hell my 2.8 has tons of power and its stock. some of these motors had power and others didn't. i would deff check the timing cause it sounds like its to low and not at 12 degrees were it should be.

[83S154x4]

put new fuel filter on, after some complications involving twisting and snapping the metal fuel line that goes in.....my bad.....got a little bit more power, but still feels like it's lacking....can't check timing, i don't have a timing light. is there anyway to adjust the spark timing that's real quick and simple?

[jamesbaird01]

if u have really good hearin u can do that way. i know about the no power 2.8l thing when i first got my truck it had power i killed it last year. rebuilt the moter [40. over, comp cam, deakt heads+block, reground valves and 3 agie on heads,headmans,2.5 exaust, no cat to dules out back.]alot of time and money and it sounds grate but still dont fill like teres alot there. atleast put it this way i use to be able to pull a 6x12 loaded with lawn equip up steep drives with the ac on 2 years ago. after the built moter i can bearly make it.

[taylordoege]

It is not the timing but it is the reason. You need to get a timing light.... any way possible. but when you time it you have to disconnect the wire under the glove box. it should be brownish... then let it idle for a half minute and shut it off, then plug back in. that is if it is electronic advance. if it is vacuum then im not sure.

[Rebel_US]

Quote: Originally Posted by 83S154x4

...can't check timing, i don't have a timing light. is there anyway to adjust the spark timing that's real quick and simple?

a rough method: by ear

accurately? a timing light

The ear method takes years to learn/acquire but is usually done thru trial and error: move it, drive - it sucks? Stop, move it, drive, etc. You have to understand what it is your adjusting to know if your getting the expected results.

Turn it a bit - better or worse? If worse - go two steps the OTHER direction.

[SH-60B]

Quote: Originally Posted by taylordoege

It is not the timing but it is the reason. You need to get a timing light.... any way possible. but when you time it you have to disconnect the wire under the glove box. it should be brownish... then let it idle for a half minute and shut it off, then plug back in. that is if it is electronic advance. if it is vacuum then im not sure.

It's an '83 so it has a vacuum advance. '82 to '85 have vacuum. Disconnect the hose from the dizzy and plug it before setting initial timing.
If your'e going to time it by "ear", advance the timing a little at a time until you can hear it ping under acceleration, then back it off a tiny bit til you can't hear it. Keep an eye on the spark plugs too. You're looking for a tan color on the insulator. If it's white it's too far advanced, white with little specks on it is aluminum from the pistons - way too far advanced.