Engine loosing power on acceleration?

Try checking the throttle position sensor, MAP/MAF sensors, to include a check on the exhaust system for restriction.

These guides can help is fix it

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

and

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

Please run down these guides and report back.

In reply to that, I did not provide the information that the vehicle will surge and be fine to drive occasionaly, It will drive then die out at a light when taking off on green. (put head down, people dont like that) I Had the parts store pull codes, six different codes this morning all for o2 sensors, so i need to still replace the four of them. Can O2 sensors be responsable for this kind of behavior? Or are they sensing a larger problem causeing them to say the vehicle is running rich? Leading me to believe, how do 4 sensors go bad overnight, and could the catilac convertor possibly be to blame?

it was the MAF sensor I got a new one and the power came back

I have an '03 Chevy S-10 with just over 70K miles Auto, 4WD, V6 4.3 that I just had a wire replaced that led to the coil pack(?). The truck started hesitating and eventually shut off. After replacement of said wire I have now noticed that the truck loses power up hills. I give it more gas and it slowly gains speed. Before it would jump and run! I also had a problem when I engaged the cruise control. the truck lost power going up slight grade and when the cc kicked in to get back to speed the engine revved to point of almost red line before I hit the break pedal to disingage. It did not pick up any speed during this incident. There is a dual exhaust on and I have noticed it is too quiet! The engine sounds like it is being overworked and exhaust pressure is from front not back of vehicle! Some rattling when I stop. This seems to come from below and not the engine. I have had 2 diagnostic tests in last 3 weeks and nothing showed up. Thought maybe it was catalytic but assume this would show on diagnostic test. Fluids are full and oil recently changed! No warning lights on. Any help appreciated!

I had an 88 S-10 and it had a very similar symptom.

Mine would rev, but generate so little power it barely moved. I got underneath and removed the O2 sensor and tried it again, the thing ran like a beast! backpressure was the reason and a clogged catalytic converter was the cause.

I surmised that the O2 sensor had failed and the computer had wound up making the mixture excessively rich.. either that or some other fuel contaminant had clogged the cat. I replaced the cat and the O2 sensor and the truck ran well until I traded it in on a 2004 Colorado.

Good luck with the issue

RC

Normal speed runs fine but on acceleration bogs and has no power cuts out a little. Getting no indication from check engine or codes.

Hello there and thanks for using 2CarPros.com. You should start by running a fuel pressure test, The truck may have some fuel pressure but may be losing fuel volume upon hard acceleration. Start with a fuel test and go from there.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

My truck has been giving me problems for a while now. It used to idle really rough and had no power at all. I replaced the catalytic converter and bank 1 sensor 1 O2 sensor. It seemed like it solved the problem. It ran fine for about 2 weeks and now the problem returned. It idles pretty well but has no power when I stab the throttle (won’t go above 2,000 rpm's) it seems to be running rich since I smell fuel. I replaced the TPS, the MAP sensor, MAF sensor. Getting a MAF sensor code (P0101) as well as a engine misfire code. Also just recently got a MIL circuit malfunction code (P0650) and noticed the lights pulse while running. Thinking that’s the alternator going bad. Could the alternator be a cause of this problem? Also replaced fuel pump and filter last year. Did a fuel pressure test and got 55psi right before start up and holds pressure. At idle I get 55psi and when I stab the throttle it jumps to 60psi but stays at 60psi even when engine bogs down. After shut down it goes to 55psi and holds. Is this sensor related, could it be electrical? I’m going to replace the plugs and wires, is that a step in the right direction? Did the cap and rotor last year. Also what about the alternator and the engine light/MIL code? Please help, I’m running out of options here and really would like to stop pouring money into this thing with no results.

Hi,

The P0650 indicates there is a malfunction in the MIL control circuit. I don't feel that is related to the alternator.

Tell me. You indicated that you smell gas. If your scanner have a live data setting, let me know what the short term fuel trims are. Also, I know you replaced the catalytic converter already. The idea that you smell fuel may be indicating a rich issue and may have already damaged the new converter. Take a look through these links:

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

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

Now the link says to remove the converter. If you remove the oxygen sensor upstream from the converter, it will make a difference if the converter is once again plugged.

Also, are you certain there are no major engine vacuum related issues? Here is a link explaining how to check:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

_____________________________________________

As far as the P0101, you are correct it is related to the MAF. However, it could be an electrical issue or even a vacuum leak causing a variation between the MAF and the manifold absolute pressure sensor (MAP). Here are directions related to the P0101. They explain the code, possible causes, and the pics attached below are diagnostic flow charts.

__________________________________

2002 Chevy Truck S10/T10 P/U 4WD V6-4.3L VIN W
P0101
Vehicle ALL Diagnostic Trouble Codes ( DTC ) Testing and Inspection P Code Charts P0101
P0101
CIRCUIT DESCRIPTION
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The powertrain control module (PCM) uses the MAF sensor signal in order to provide the correct fuel delivery for a wide range of engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle. A large quantity of air entering the engine indicates an acceleration or high load condition. The MAF sensor has the following circuits:
^ An ignition 1 voltage circuit
^ A ground circuit
^ A signal circuit

The PCM applies a voltage to the sensor on the signal circuit. The sensor uses the voltage in order to produce a frequency based on inlet air flow through the sensor bore. The frequency varies within a range of around 2,000 Hertz at idle to about 10,000 Hertz at maximum engine load. The PCM uses the following sensor inputs in order to calculate a predicted MAF value:
^ The manifold absolute pressure (MAP)
^ The intake air temperature (IAT)
^ The engine speed (RPM)

The PCM compares the actual MAF sensor frequency signal to the predicted MAF value. This comparison will determine if the signal is stuck based on a lack of variation, or is too low or too high for a given operating condition. DTC P0101 sets if the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0121, P0122, P0123, P0335, P0336, P0401, P0440, P0442, P0443, P0446, P0449, P1106, P1107, P1111, P1112, P1121, P1122, and P1441 are not set.
^ The engine is running.
^ The ignition 1 signal is between 11-18 volts.
^ The throttle position (TP) sensor angle is less than 95 percent.
^ The change in the TP sensor angle is less than 5 percent.
^ The MAP sensor is less than 80 kPa.
^ The change in the MAP sensor is less than 3 kPa.
^ The above conditions are met for 1.5 seconds.

CONDITIONS FOR SETTING THE DTC
The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds.

DIAGNOSTIC AIDS
Inspect for the following conditions:
^ An incorrectly routed harness. Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:
- The secondary ignition wires or coils
- Any solenoids
- Any relays
- Any motors
^ The throttle plate for sticking, or for deposits on the throttle plate or in the throttle bore.
^ A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
^ A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 6-12 g/s at idle to 130 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
^ The barometric pressure that is used in order to calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running the MAP sensor value is continually updated near wide open throttle. A skewed MAP sensor will cause the calculated mass air flow value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
^ A high resistance on the ground circuit of the MAP sensor may cause this DTC to set.
^ Any loss of vacuum to the MAP sensor may cause this DTC to set.
^ A high resistance in the ignition voltage circuit of the MAF sensor may cause this DTC to set.

If you suspect the condition may be related to aftermarket accessories, refer to Checking Aftermarket Accessories in Diagnostic Aids.

If the condition is intermittent, refer to Intermittent Conditions. See: Computers and Control Systems > Initial Inspection and Diagnostic Overview > Intermittent Conditions

TEST DESCRIPTION

Steps 1-6

pic 1


Steps 7-11

pic 3


The numbers below refer to the step numbers on the diagnostic table.
4. This step will determine if the MAP sensor voltage is within the proper range at idle.
5. This step will determine if the MAP sensor responds properly to the change in manifold pressure.
6. This step will determine if the throttle position (TP) sensor is operating properly.
7. This step will determine if any mechanical faults have caused this DTC to set.

______________________________________

Let me know if any of this helps or if you have other questions.

Take care,
Joe

loss of power &acceleration after about fifty miles of highway driving.

Hi:
Is the check engine light on? It sounds like you have a catalytic converter that is going out or a MAF sensor that is bad but to be sure here are three guides to help us fix it.

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

and

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

and

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

Please run down these guides and report back.

One more question, when it looses power, does the engine studder or feel like it's going to shut down?

Let me know.
Joe

put on new fuel pump&filter ,changed plugs,oil, put tester on codepo340 cam position sensor,put that in about 2 months ago

TPS check out ok? does it do it same worse when driving?

IT IS WORSE WHEN IN GEAR

what about possible vacuum leaks?

is light back on? any new codes?

NO LIGHTS SAME CODES

A FRIEND SAID IT SOUNDS LIKE TIMING CHAIN

when those 4 cyl engines arn't running right they can sound like lots of things.

2000 Chevy s10, acts like its running out of gas. Total loss of power once the truck is warmed up. Out of ideas. We have already done a complete tune up, replaced the injectors, the o2 censors, the maf censor, and the computer for lack of a better idea. The fuel pump and catalytic converter have been tested and are working fine. Anyone have any other suggestions?

Have you checked for vacuum leaks (intake)?

Can you give us a better description of what exactly happens? Is it just a smooth loss of power or does the engine get rough running or buck or surge or anything like that? Does cooling it down correct things?

This guide should help us

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

Please run down this guide and report back.

Not sure about the vacuum leaks but they've checked all the obvious. As far as a better description, I'm not really sure. It's my husbands truck I've only been in it a few times and the running outta gas analogy is the best I have. It doesn't completely stop running but it maxed out at like 30 mph and that's floored. It used to be when you shut it off for 15 minutes or so you could drive it for another couple miles but now it doesn't matter if the car is cool or not it still has no power.

That really sounds like a plugged exhaust/converter. I don't know how they would have checked that but they need to take a pressure reading after the symptoms are present.

He took the exhaust off over the weekend and it didn't change anything. A few weeks ago the converter was hooked up to machine at a smog shop and he drove around with it hooked up, pressures fine... I appreciate your help though.

How about the fuel pressure? Did they monitor that while driving?

Yes sir.

And what was it when the problem occured?

I'll ask my husband for the exact reading cause I'm not sure but they ruled that out right away.

You may end up needing a scan tool to analyze what the sensors were seeing at the time. If anyone has a professional scanner, have them freeze frame the data stream at the moment the problem is at it's worst.

2.2L s-10 186,000 miles
Truck ran well until the other day, major loss of power and can't get over 30mph. Changed the fuel filter and it appears to have good exhaust flow, so I don't think th cat. conveter is plugged and I checked the plugs. It idles fairly well but when you press on the gas, it just boggs down, like it's fuel starved. There is no scrader valve to check the fuel pump pressure and no codes. Does this model have a remote fuel pressure regulator? Any other things to consider besides fuel pump?

you might want to clean your carburetor or get a new one and if the carburetor isnt the problem then u might whant to check your coil wires one may be disconnected, broken/bare, or just burnt up.

Does the check engine light need to be on for that cause that was the problem the last time they ran a diagnostic test on it. It wasn't coding anything out cause the light wasn't on. Who would have a scanner? Any shop or would auto zone rent one?

Checked fuel pressure, it's too high, 50 with key on and 60 running.

Pulling codes is not a diagnostic. Not even close. There is a world of information available from the computer but much of it requires professional scan tools. Not the $100 tools they have at AutoZone but the $5000 to $20,000 tools that we have to buy to be able to find these problems.

I have replaced air filter, fuel filter, plugs, wires, dist. cap, and MAF. My truck acts like it has no power. There's no hesitation it just accelerates very slowly. Any Ideas??

I also had to replace the fuel pump. It completely died on me. I have been have this problem for about a year. Nobody can tell me what's wrong with it. It's gradually getting worse. Please help.

I recently inherited a 2000 Chevy S10 2.2L with acceleration issues in both drive and reverse. From a cold start the engine sounds like its rushing air and has little to no power. After it has warmed up a bit... The engine still lacks power and shakes at a slow idle. On the expressway the truck seems to be lunging while in cruise control. I have never owned a Chevy before and was curious if you had any suggestion on what to fix or try first.
Thanks,
Matt

First thing get the computer scanned for codes.Then let me know the exact code numbers not code descriptions?

There is no check engine light on. no codes popping up at autozone