loses power and hesitates

start with a compression test. test the fuel pressure and timing. make sure your plugs and wires are in good working order.

Check out tis guide

https://www.2carpros.com/articles/engine-has-low-power-output

Roy

i have had a compression test and plugs and whires are new

new fuel pump filters throddel body rebilt new injectors and throttle sensor new o2 sensor

did you have the cat converter checked for being clogged??

Roy

the cat converter has been replaced the power is back! thank you

idle good .when under a strain loss of power changed spark plugs and wires o2 sensor less then a year ago cc has been cleaned out when i pull up to a stop sign wants to die

Hello well you could have a fuel pump that is going bad and may not be delivering the correct presure to the throttle body. Or you could have a simple fix and check to see the last time the fuel filter was replaced.I hope this will be of some help to you.

Alright I put a new Fuel Pump , Distrubtor cap, and rotor button on it, what the truck is doing is, it will run fine until it gets warm then it loses power and seems to only run on a few cylinders, It did it to me on my way to work, i turned around and drove home very slowly , then it like cleared out and ran fine again? any ideas

Hi
Well when you replaced the fuel pump did you replace the fuel filter at the same time, if not they can get clogged and may cause the truck to run like its running on a few cylinders.

I have done a complete tune up and then some. Plugs, plug wires, cap, rotor, air filter, coil, water temp sensor, map sensor, throttle position sensor, new injector. The problem is when it is at idle and while driving(usually when I am just cruising, not under exceleration) it hesitates or almost cuts out, or lack of power then service engine soon light comes on but is only on a minute or so. When I put it on the computer it says O2S rich. I just dont know what else to do.

Maybe the O2 check voltage output of O2 if .1 or higher then O2 is telling ECM its rich and it leans out till engine stalls.

So if I check the O2 voltage and is higher replace the O2 sensor? To explain a little better. What it does is at idle it will go to a low idle then idle back up. When it idles to low it almost dies, then the ses light comes on. When I am driving at a sustained speed like 35 MPH then excel it hesitates like it has no fuel then goes, then light comes on. When I excel it runs fine then light goes off. Whenever I put it on the computer same code O2S rich. Oh yea when connected to the computer it says it is running lean. I am confused.

If O2 sends rich signal to ECM then it will lean fuel mixture by limiting pulse and length of injector spray

well I still dont know what to do. I understand that if the O2 sends a rich signal the ECM will lean it out. I understand that. I am using a MAC tools computer scanner. The O2 is switching between rich and lean, which is normal. But my question is how quickly should it do this? I just dont know what to do.. I cant keep throwing money at this. It is almost like it loads up on fuel or something. Please help

Here is a check for O2. Disconnect O2 sensor wire connect DVOM in series ie. between O2 and wire connection Set on 2V scale. Next ECM pull down pass side under dash find Purple wire to O2 terminal D6. Take long jumper wire touch purple wire term and to pos battt term. Observe DVOM voltage should drop to .3v. Next switch to neg batt term. Observe DVOM voltage should go up to .8v.
Do this with engine at normal temp and running.
Let me know what you get

Does not have full power and sometimes it back fires.

Check general tune first, check for cross firing leads or cap start here.

Can you explain that in simple terms. I think you said to check that it does not need a tune up, and that wires are not mixed up with plugs?

Hey, JEANNIE

It should be the catalytic converter, here is a guide that will go over the first things to check when you have low power.

https://www.2carpros.com/articles/engine-has-low-power-output


Let me know what you find so we can continue.

Best, Ken

So, I talked to the owner and wrote down word for word what he said. " sluggish when you first take off-gets better as you get going." Once in a while it "back fires" outs'm Ute liter a little popping noise. Replaced, plugs and wires, cap and rotor, and fuel filter about a year ago. Transmission is good.

It sounds like the catalytic converter is getting plugged up or the fuel pump is weak, here is two guides that can help you.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

and

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know what you find

Best, Ken

Engine Performance problem
1991 Chevy S-10 Two Wheel Drive Manual 140000 miles

i have a 2.8L s10 5 speed. has new plugs, wires and distributer cap. I recently changed the fuel filter and alternator.. when idling it seeems to run fine (runs smooth n does not seem to miss at all) n seems 2 have a lot of power when revved, but when put in gear it does not seem 2 have the acceleration it should.. when i make it to 60 (which sometimes takes a while) it loses power goin up hills n slows down. i usually have to drop it in 4th to speed back up then go back to 5th. ive been told a few different things that could be wrong.. What do u think?? thank you

Have you checked fuel pressure? check spark is it blue/white spark?

no i havent ckecked those.. how do i check fuel pressure n what will i need?

Need pressure guage should be 9-13 psi

ok.. where on the vehicle do i check the fuel pressure at?

Just ahead of fuel filter seperate steel fuel line from flex line install gague

my S-10 (5 speed extended cab 1997 is missing the wiring that runs from the alternator to the engine i need a diagram of how to rewire properly can anyone help me?

My 1989 S10 2.8 pickup loses power after a few miles of running and will completely stop running. After a few minutes it starts up and runs but with little power. The fuel pump and filter have been replaced.

The battery and alternator are also new. It begins to lose power after a few miles and eventually winds down completely. After a few minutes it will start up and run for a while and quit again if power is called for.

It sounds like the cat converter is bad, follow this link

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Let us know what you find :-)

My truck starts up just fine and will come to a good idle after a couple minutes of warming up it can drive. but it seems like after 30 minutes of driving or so when I come to a complete stop and then I slowly release the clutch and press the gas the more I press the acceleration the more it seems like it wants to bog down and shut off. but if I take my foot off the gas it idles just fine and is even worse when sitting at a little hill I almost have to slip the clutch and slam on the gas just to get the truck to finally go and get it to where I need. Not really sure where to start looking. could be multiple problems.

You are correct that this could be multiple issues. So let's start with the low power or hesitation on acceleration. Here is a guide that will get us started on possible causes:

https://www.2carpros.com/articles/engine-hesitates

I suggest we need to start with checking the fuel pressure when this is happening. Here is a guide that will show you how to do this:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If the fuel pressure is okay then we can move on but I suspect we are going to find an issue with this as it sounds like a fuel issue. I also attached below the process from the manual. Let's start with this and go from there.