I have a 94 non turbo 850 with 102,000 miles. I bought this in August 06 with about 92,000 miles and within 1 month needed to replace my O2 sensor and got a tune up because of the car "bogging" whenever I tried to accelerate. That seemed to do the trick and now I have a more annoying issue. I have very poor acceleration no matter what speed I am going. I am able to accelerate up to around 30mph without having to really punch the gas, however it still takes a while to get to that speed. When I want to go over 35mph FORGET ABOUT IT!!! I try to step on it and all i get is my revs going up to around 4500 and then i just shut it down. I took it to my mechanic who deals with volvos and he is dumbfounded. He said that he has tried everthing he can think of but can't figure it out. He has replaced the fuel filter...then the mass air flow sensor. Neither have done anything. He said the next step would be to check out my transmission. Anyone have any idea what I could check out or maybe have encountered the same problem??

 

My money is on a bad fuel pump. It's not able to deliver enough fuel. But what do I know, I'm not a mechanic

 

I was going to suggest the Mass Air Flow sensor, but I see that has already been changed. I'm betting on a fuel pump as well. Also might want to check the air filter. I have seen some that are unbeliveably clogged!!

 

Well the fuel pump checked out just fine. The filter was replaced and still nothing!!!! [:@] any more ideas??

 

I hate to ask a stupid question but has your mech even looked at possible codes that are stored in the cars computer?

This might be an answer to your problem.

I forget what what the correct term is but it sounds like your car is in a loop. It wont let you go over a certain speed.

 

>When I want to go over 35mph FORGET ABOUT IT!!!
That I will[8D].

As Moderator S70 has noted, the car may be in the "limp" or back-up mode, which let you drive enough to get home (or to a dealer[8D]) but the original performance is lost. I would like to ask you a few questions:

1. Is the "arrow" on the dash flashing? (On automatic, this indicates the transmission is in limp mode as well.
2. Is the "Check Engine Light" on?
3. Is the transmission fluid level at proper level? If you'd like to know how to check it, refer to the owner's manual, or ask us. You can't just pull the dipstick and re-insert it as you do with engine oil.
*To check for CEL & Tranny arrow, turn the ignition key to "ON" (not START). This will light up the warnings on the dash momentarily.


Here are some items I would check (after checking for possible codes in the engine & tranny):

To isolate the transmission and check for engine operation:

With the shifter in P, try revving the engine. Does it rev up smoothly past 4,500 RPM? If so, the problem may be on the tranny side. If the engine stumbles, it probably has nothing to do with the tranny.

1. Intake air supply: Make sure the air filter is not too dirty. On rare occasions, even clean-looking air filter can be clogged with micro-sized pollen if left too long. Also, make sure that there is no rupture/damage along the intake hose.

2. Make sure the compression is good. This can be done at a shop with compression gage, but can also be observed by rapid consumption of engine oil, or blue smoke from the tail pipe.

3. Make sure nothing is restricting the exhaust line. If there is a blockage in the exhaust system, it can prevent the RPM from going up.

4.Make sure the throttle body is not too dirty.

5. The injectors may need to be cleaned.

6. Make sure that the ignition components are good (plugs, wires, distributor cap & rotor: Look at the ignition coil at night with engine running; if you see arcing around it, it's time for a new coil).

7. Make sure the accelerator cable is opening the throttle properly. Do this with the engine off and have someone floor the gas pedal while you observe for the movement of the cable, or you can disconnect the intake hose and watch throttle valve for correct opening.

I hate to mention, but the mechanic did not sound too privy to 850s. He seems to be attacking the problem rather randomly. Give him another chance, and if it doesn't work out, you may have to give up some $ and visit a dealer. But make sure to tell the dealer exactly what you've tried, and talk like you know what you're talking about just to avoid getting ripped off.

Also, give us a bit more findings if you possible.


JPN

 

Nice to see you back on the forum, JPN.

Regards
Axel

 

'S70driver - Yes, he did check the codes and the only thing he could find a bad reading on was the RPM sensor (not sure if that's the technical term). Soo that was replaced back in Sept I believe with a used one because that was causing the car to "bog" and it worked great, but because he got a bad reading he replaced it with a brand new one. Ironically I had originally replaced it with a brand new one but the dealer part was bad, go figure...so he replaced it with the used one.

 

JPN - Thanks for all those ideas to troubleshoot my problem!! I just got back from July 4th vaca and im gonna run it by my mechanic. I think if none of these happen to work, that I will take it to the Dealer and at least have them diagnos it and then maybe go back to my guy to try the fix...or just bite the bullet and have the Dealer to it.

 

Axel,

Thanks, it was a looong time being away from the forum. I missed it very much. Now Tech seems to be taking his turn, he seems to be taking vacation to NJ.

Chrome2386,

I hope I've given you the right direction. For general maintenance questions, refer to the following:
https://volvoforums.com/m_48928/tm.htm

I wish you the best of luck, keep us updated if you would.


JPN

 

Check the transmission fluid level and condition of the fluid. If you are trying to accelerate and the revs are going up but the car isn't moving, I'll bet your trans fluid is either low or totally burnt up. Check for leaks and drain and refill, run it through all of the gears (sitting still), and drain and refill. Do this a few times (maybe 4?) or until the fluid runs clean out of the drainplug. Refill it and take it for a spin.

 

JPN - I talked to my mechanic and he has tried all of these things, except I can't confirm about checking the trans when in park. I am pretty sure he has tried that because it was one of the first problem spots we had talked about. I'm giving him today and then I am taking it over to my local volvo dealer and have them at least diagnos the problem.

Thanks, Matt

 

xjflexer - The trans fluid is at normal level. I have heard that because of the mileage of a car, that replacing the trans fluid isn't good. This is because the car becomes accustomed to the fluid and newer fluid kinda throws the trans into shock and everything isn't able to run as it was used to. Do you or anyone feel this is false information?? My father had a 94 Ford Tauras and he replaced the trans fluid around 92,000 miles and when we got to around 98,000 miles the trans starting shifting all sorts of weird and knocking. Not sure if this was directly related to changing out the trans fluid but it's in the back of my mind. But of course its not like my cars running right anyway [:@]

 

this might sound dumb but when ever my 850 is slow as crap ( i could like run faster than it) it's beause the switch is on economy. maybe your switch is broken and stuck on economy causing you to have poor acceleration.

then again i am probably completely wrong, but i'm just throwing something out there because when my car is switched onto that it basically does the same thing. i could floor the thing and it barely wants to move.


good luck trying to get it figured out, broken cars are no fun

 

I kind of agree with JPN's earlier note about checking the exhaust. It could be a clogged cat. It can be checked by dropping the exhaust and noting if the RPMs run noticeably smoother.

I also would have the throttle position switch checked. Its located below the throttle body and Terminal 3 should have between 0.5V(throttle closed)and 4.5V(Wide Open Throttle). This will directly affect acceleration.

 

↑R.Branson?

I now don't feel like blaming your mechanic.

I am suspecting the RPM sensor at the moment, as it was causing the problem initially. Maybe the electrical connection got loose, etc... But it would have thrown code if that was the case (but Volvo's self-diagnostic is sometimes unreliable).

Or, the transmission may be stuck in the "Winter" mode, but then you would see the arrow on the dash, unless the light bulb for the warning is shot.

Or, something is telling the ECU to limit/cut fuel supply at around 4,500 RPM.

Or, some accessory components are exerting additional load on the engine (not likely, though).

Now I'm the one who's going random[8D].

Without actually taking a look at the car/testing itmyself, I cannot come up with better solutions.

Sorry couldn't be of better assistance.


JPN

 

And if all else fails, here's your last resort; every mechanic should have one of each in his/her toolbox. Check with your local law for appropriate applications, though[8D].


JPN

[IMG]local://upfiles/6892/81A22FF7B22F4C4B961ECE88767BC945.jpg[/IMG]

[IMG]local://upfiles/6892/6C41DFD1467B4C82B6FB85D1C8FA497F.jpg[/IMG]

 

green850 - Thanks for the suggestion. I think maybe you meant it's stuck on "winter mode" because I believe that starts me off in 3rd gear for the snow. I'll see what my mechanic can come up with cause any suggestion is much appreciated!!! Also what's the point of the Economy/Sport modes...is it just about where the shift points are? I'm not to up to date on it and just curious.

 

01_fast_ride - well checking the cat sounds logical at this point cause everything else has failed, kinda weird that it would have clogged all of a sudden and done this but why would it be something simple anyway I'm pretty sure that he checked that throttle position but it won't hurt to mention it. Thanks!!!

 

JPN - I was told that there was a code throwing off the RPM sensor and that he replaced it, but of course that did nothing. Im thinking now that the winter mode might have something to do with it cause thats what the car feels like its in. I have a sound system in my car, but that's the only accessory that I had added on but I know the previous owner had one also and that it never affected anything. All that does is drain power from the battery anyway....and seeing that I live in Philadelphia where the murder rate is over 200...I don't think that they will even notice if I use "force" to beat my car until it works