Sudden loss of acceleration and power

This type of problem is very difficult to give advise online without actually checking the car out? The problem you are describing sounds like you are having an issue with the electronic throttle module. For the throttle to work properly you need good battery voltage going to the throttle. One thing you should really check when this happens is the charging system. There was some issues with the voltage regulator when it would get hot while driving for a while, the voltage regulator would just start to quit. If Voltage to the throttle goes low enough then the throttle stops responding. Most of the time there will be no messages on the cluster or warning lights but I would highly recommend you go to a shop that can actually scan all the control modules especially the central electronic module and the electronic throttle module for codes related to low battery voltage. If there is voltage codes then most likely the voltage regulator is failling. If you order one from Volvo, they stock an upgraded version of the regulator. Compare prices for the regulator vs. a complete alternator. If you are not saving much money, with the mileage on the car I would just replace the whole alternator. If there are different codes then further diagnosis would need to be done to see if it is a bad throttle, bad accelerator pedal, or an issue with the wiring? I hope this helps you with starting with some basic steps and please keep me posted.

Sorry it took so long to respond. We did take the car to the dealer for a diagnostic and it was in fact the electronic throttle module. It looks like the previous owner had tried to replace this part with a rebuilt module. It was not a cheap repair, but the car is running perfectly now!

Thanks!

I know the problem you have no matter if car our of warranty Volvo should take care of it. The car you have is missing a cylinder. S80 you own should use a b5204t which is a in line 5 cylinder that is turbocharged. 180hp 240ftlb torque.

Great addition to this thread! Please feel free to help out whenever you are on the site :)

Cheers, Ken

I was having problems with the car idling up and down so I found a video about cleaning the etm unit so I cleaned it and that fixed the idling problem but it still lacks power when I press the gas pedal, thanks in advance

Check to make sure fuel pump pressure is within spec. Make sure there are no vacuum leaks. Check for tune up.

I'm going to do a tuneup this weekend and if I had a vacuum leak wouldn't it set off the service lights?

Engine Performance problem
1999 Volvo S80 4 cyl Front Wheel Drive Automatic

there is little or no acceleration when pedal pressed i have aready changed accelerator pedal with new one and i have same problem

Check battery condition and charging system for proper voltage. Voltage drop battery cables. Check electronic throttle connections for proper conection, inspect pins for oxidation or damage. Chek for an open or short circuit from throttle to engine control module. If all looks good then you will need a new throttle. You may also need to have the new thottle loaded with software since it needs to be configured to the vehicle which only Volvo or a shop able to download software can do.

Shakes or Wobbles problem
1999 Volvo S80 6 cyl Front Wheel Drive Automatic 110,00 miles

From a standstill, during rapid acceleration my car shudders just for an instant as it changes gears, but during normal acceleration there is no shudder. Also, when going over dips on the highway at normal speeds there is the same shudder, but once I accelerate it does not happen at all.

If you have a shudder during a gear shift then your transmission fluid is contaminated with coolant. You would need to have a glycol test done on the fluid. If it is contaminated then you will need to replace the transmission, radiator, and transmission lines.

Changed spark plugs and added fuel injection cleaner...car will not go above 20mph, and that is after it builds up speed. However, every once in a while, the car will drive just fine until it is turned off, then it starts shaking and driving slow again.
* Codes are not able to be read, there is something blocking the reader from reading them, the blinkers are not working, lights are dim on dashboard, and airbag warning was on before car completely broke down. Also, had to replace battery 4x in 3 years, not sure if those are related, I am just trying to get my car running so I can get to work.

Suggest have Alternator output checked

S80 Automatic. There is a lack of power when trying to accelerate from zero, especially on a hill. You can press the accelerator fully, but there is very little response?
Will send a donation next week
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This car has what is called a drive by wire throttle system, they go bad a lot, the only thing you can do is take to a volvo dealership and have it repaired, after it is replaced the system will have to be relearned, usually they are the only ones equipped to do this, it is very expensive. Thanks for using 2CarPros

Has the check engine light come on? If it has can you post the codes on here to see whats going on? Also is these a turbo engine or non turbo? If these is a turbo engine and all of a sudden the turbo stopped working it will feel gutlas. If these is the case I would check all the vacuum lines to the turbo. They usually split open especially on the twin turbo. I would also look into the turbo control valve since they fail a lot as well. If these is a T5 inline 5 cylinder I would look at the rubber hose on top of the turbo for a split. Very common on the T5. Also look at the rubber charge air pipe to the cooler. But if the check engine light is on start with having it scanned first and posting the codes on here.

Engine Performance problem
2001 Volvo S80 6 cyl All Wheel Drive Automatic 80,000 miles

we have had it looked at but it still says performance reduced? he does small sputters and jerking motion..help!

Inspect and test all the following listed below:

Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note:If it doesn't apply disregard

Performance reduced warning message is almost like having the check engine light BUT this is actually for a problem relating to how it is going to effect the electronic throttle module so a regular OBD2 code reader will simply not pick up actual trouble codes then if you were to take it in to Volvo. Do you know what codes were happened to be scanned and tried to diagnose? If you have an issue with the electronic throttle you may still be covered by the 10 year/200k mile extended warranty but you will need to call Volvo to verify that it is. Also they would need to diagnose the vehicle and run some tests to verify that it is bad. Also when you call Volvo ask to see if campaign 155 has being completed yet on your vehicle. That was a software update for the electronic throttle and sometimes that will solve some issues with the throttle. But if the PCV system is dirty and the throttle plate is dirty as well, you will be responsible for paying diagnostic plus the repairs if you decide to have them do it. If you want to avoid going to the dealer then I suggest you find a shop that specializes with Volvo cars but you could be missing out on a free throttle repair which could cost you a minimum $1000. Hope this helps and keep me posted please.

2001 Volvo S80 Two Wheel Drive Manual

acceleration problem

You should cal Volvo to find out if your electronic throttle is still covred under the 200k/10 year extended warranty. If it is then Volvo will need to diagnose it to verify the throttle is faulty.