Engine idles fine but no power on acceleration?

hmmm.........does this prob happen when the engine is cold or only after it warms up/been running for 5 mins or more? could possibly be a bad IC module. if happens after a few mins of running. sounds like the same thing on my S-10. no power/stumbling on its face at full throttle, only way to check fuel pressure is to make a connection after the fuel filter with a homemade device that has the proper fittings for the lines and the gauge. This guide should help us

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

Please run down this guide and report back.

I just did the catalytic converter on my truck runs like new! make sure you hit the bolts with wd40 before you begin helped me a lot.

My problem begins with a slight jolting if i step on the gas too hard and after the engine warms up its almost impossible to accelerate because the jolting is so bad. The truck refuses to accelerate like if somebody was pushing and releasing the brake in intervals while im stepping on the accelerator.

I checked the catalytic converter and it was fine.

Do you have a check engine light or has flashed?

Last major tune-up and what was replaced and adjusted?

Check the fuel pressure and the throttle position sensor-

[quote:c23dfdea74="rasmataz"]Do you have a check engine light or has flashed?

Last major tune-up and what was replaced and adjusted?

Check the fuel pressure and the throttle position sensor-[/quote:c23dfdea74]
no the check engine light hasn't turned on and haven't had a major tune up since i bought it like 2 years ago other than checking and changing fluids....

oh man and i forgot to add a piece of information. It does fine towards the end of the gear but its the beginning (the first half), when i first shift in the gear that it jolts hard. After it warms up, it jolts the entirety of the gear. It does this for all 5 gears.

Give it a tune-up-and check the fuel pressure/throttle position sensor.

1995 Chevy S-10 4 cyl Automatic

My 95 s10 is acting up on me, ill drive it a few miles and then the power steering goes out and when i try to give it some gas it wont go and the motor wont rev,so i have to put it in park turn it off and start it back up and go alittle more ways but it then dies out again.. i just put a new fuel pump and filter on today, i have put a new modual on but no the whole modual thing just the little part that goes behind the carborator.

get teh engine scanned if you can. then when it is running hook up a vacuum guage and see what it reads at idle. if it reads 15" or below you may have a clogged converter. if iti's that all you need do is disconnect teh converter and if the engine runs ok then you get a replacement for it.

I cannot figure out what is going on with this truck. It has a 4.3L engine with "Z" VIN code. I replaced the plugs, fuel filter, distributor cap and rotor, MAP sensor, and IAC valve. None of these things has helped. The TPS seems to be working correctly as I tested it with a volt meter. I replaced the MAP sensor because it was receiving 5 volts but the signal wire showed a voltage of 1.4 volts and did not change with suction. The IAC valve was stuck so I replaced it. The EGR valve tested correctly and wasn't replaced.

When I start the truck(starts easily) it will idle at around 1000-1100 RPM for a about 30 seconds and then drops to about 600 and then to 500 and then stalls. It will staying running if the accelerator is pressed but it is weak during acceleration.

Any help would be appreciated.

Start by checking the fuel pressure. If it drops off as the engine speeds drops, suspect a plugged or collapsing pickup screen in the gas tank.

I greatly appreciate the quick response. I have a fuel pressure test gauge but I cannot locate a Schrader valve on the truck. The fuel lines exit the throttle body and proceed down the firewall. Most pictures I've found show a Schrader valve on the top of the engine on the driver's side however the engines are not identical to the one I have.

I have the same problem, and I've been running with a pressure gauge attached for over a year. My problem only occurs in warm weather and it just acted up today. You need a full set of adapters so you can find a rubber hose to pull off and insert a "tee". You may also find an aluminum block that screws into the throttle body in place of the supply line, and the supply line screws into that block. Either of those adapters will have the port to connect the gauge. Many auto parts stores rent or borrow tools and they will have the complete set of adapters in the kit.

I have a domestic fuel pressure gauge by Actron and I found the adapter I need on their site so I will try to pick one up tomorrow. I will reply with what I find out in the pressure test. Thanks so much for your time.

No one has the adapter that I need to attach the Actron fuel pressure gauge to the system. Can anyone provide any ideas on how to go about doing this? It seems i'd need to plumb one in with a scrader valve.

I don't have a test port either. I removed the rubber hose between the engine and fender, then inserted a tee and piece of hose that was part of my kit.

Hi..this is for a 1995 chevy s10, 2.2L four cyclinder, automatic and regular body style with approximately 170 K miles. After every long trip I have to top off the engine oil. Now, I smell burnt oil and it loses power when driving and also idles rough. Also, on your conclusion, what would be a estimate ( by average ) for repairs.

sounds like an oil leak that is getting on hot parts maybe exhaust parts. are there any codes in computer? when was last spark plug change? you may also have a dirty MAF sensor.

thx Fixitmr..spark plugs were changed one year ago..

Truck will not go over thirty mph. The fuel cuts out and starts to sputter at 2000 rpm all the way to 3000 rpm. I have changed plugs, MAP, TPS, IAT, crank sensors, wires, cool pack, cool mod, fuel pressure, fuel pump, crank, timing gears and chain ECM/ECU. checked grounds, injectors, head gasket. I check compression it is 180 across the board.

scan for codes a nd check fuel pressure with a gauge. then check for a vacuum leak pump pressure should be 41-47 psi.

I did not see where you had mentioned a fuel filter, you will want to do a fuel quantity test with the key on. should be one liter in thirty seconds if I remember correctly. Lou

Cannot, fuel Schrader valve on this truck and does not codes stored check engine light will not even come on.

Everything was good filter. It was the first thing, sorry.

Okay, if memory serves me you need to remove the fuel filter and install a T with a fuel gauge attached. also, does the truck run bad only under load? do you have a fuel injection service tool?
if so you may want to disable the fuel system and run the truck off the fuel service system. if it runs the same you know its not a fuel system issue. if it runs better then you know it is something with the fuel system.

It runs the same I have already tried it.

okay, well if you do not tell us what you have already done then how are we supposed to guide you in the right direction. :)

partially disconnect the exhaust from the manifold see if the engine runs better. you could have a partially clogged catalytic converter.

95 S-10 4x4 4.3 Z TBI A/T 15000 mls. Runs fine when cold, once thermostat opens thats when the problem begins, it misses when idling in gear and stopped, [at stoplight] if I shift into N or P it dosn't miss but tach floats 100 rpms up and down. Misses with light acceleration but not with heavy acceleration. Service engine light has never come on. Oil is clean [no antifreeze leaking in] oil pressure is fine, I have already replaced intake manifold gasket, fuel pump and sending unit, fuel filter, plugs, wires, dist. cap, rotor, ignition coil, O2 sensor, coolant temp. sensor, removed egr valve and found no carbon clogging the valve. WHAT CAN IT BE? I need help from someone smarter than me because I'm out of ideas and money!!

check the coolant temp sending unit not the sensor. also check the MAF or AIS if equiped with your model. also a dirty IAT can cause this.

I have done so much I have forgotten .

Truck doesn't have MAF AIS or IAT did you mean IAC? Coolant temp sending unit seems to be working warms up to around 200-205, once thermostat opens drops to around 150 then stays steady between 150 and 170 which is normal however before this problem thermostat opened around 190 then dropped to 150. I don't know if this is related, seems like it. cooling system is clean, good flow through radiator. Feels like a sensor is cutting fuel to injectors but no codes have been set. Tried a new MAP sensor today, runs even worse engine surges 1000 rpms at idle, service engine light comes on and goes off, can't accelerate at all without engine stalling. Starts right back up but still can't touch gas pedal without stalling. Put old MAP sensor back on.

Okay, just got back from trying that no differences.

no i meant IAT, Idle Air Intake is located on the manifold.

i think were looking at a thermastat problem. take it out and examine it, see if it opens when heated up with a hairdryer if not get a new one.

Forgiven :)
so either remove the o2 sensor and install a back pressure gauge or partially disconnect the exhaust and see if it runs better. you should never have more then 1-2 psi back pressure. pretty sure its under one psi.

okay, well if you ruled out exhaust and fue. I would take a closer look at the distributor and check the play of the shaft the rotor sits on. also, the condition of the pick up coil. not sure if I seen that you replaced that or not, but it sounds like you may have ignition breakdown. I would take a closer look at the distributor. Lou

No distributor has two coil packs and in two and a coil module.

And I have replaced both.

oh sorry, thought this was a distributor style still. If I can come up with some better information I will reply back. I am sure another tech here has run across this and should chime in. Lou

Thank you.