Hello everyone. Long time no post. I've recently started experiencing some problems with my 01 C70. Its hard to explain what its doing so please forgive me if I sound stupid. (actually when it comes to this car, I am) Sometimes....when I start my car it doesn't start normally. It starts like it barely wanted to start and kinda chugs for a bit until I give it gas. Well, when it starts this way I can expect problems. When I take off from a stop it doesn't really go, kinda "chugs" again. (don't ask me what chug means, I just use it cause I don't know how else to describe it) After I get to about 30mph it will go. When I get up to cruising speed whatever it may be, it feels like it kinda cuts out or something. Like I feel the car jerking. I guess I could say it feels like I think it might feel if I were running out of gas. Funny thing is it doesn't do this all the time. I've noticed if it starts rough like I mentioned above I can turn it off wait a few and start again and it won't do it. And then I don't have the driving problems. So because it doesn't do this all the time, my husband and brother (the 2 mechanics in my life) think I'm crazy. We scanned it a few times and nothing came up. There are no lights on. The other day my brother and I were changing plugs wires and air filter and decided to try to scan for codes. At first nothing showed, but when my brother tried to start it, it didn't start at all. (It had started previously, so I know it wasn't what we changed) He tried again, it started but died real quick. We were now able to get these codes.

P0115 Eng. Coolant temp circuit (ID: Eng. Controller)
P0722 Output Speed Sensor Circuit (ID: 18 Trans. Controller)
P0301 Cylinder 1 misfire (probably cause of the not starting)

Another funny thing it does, when it starts right and I don't have problems driving, it seems to accelerate faster then normal. Like if I push the gas from a red light, it seems to go faster then it use to. If I'm on the highway and go to pass someone, it doesn't seem to shift into passing gear correctly. The engine seems to rev up and down without me pushing the pedal.

I have gotten great advice in the past from the knowledgeable members on here and I am hoping someone has some more. Thanks in advance for all the help.

 

Could it be a problem with the fuel pressure regulator?

 

sounds like u have more then 1 problems. i suggest u hook up to vida to check for codes to run a diagnosis test first.

 

they don't have a fuel regulator really, the ecm controls the pressure,

 

i can tell you that the chugging you feeling(jerking of the car) is probably your coil pack going bad hence the code p0301 cylinder misfire and problems starting the car as well. I experienced this with my 97 960 wagon, my coil pack for cylinder 3 went bad and my car would jerk or misfire so i replace the coil pack($55) for cylinder 3. I would look at the coil pack for your car they are pretty reasonable price wise depending on the vechicle. I have a co-worker who has a 98 C-70 and 2 of his 5 coil packs went bad, I told him we should just replace all 5 as the other 3 would probably cause him problems down the line so we bought all 5 coils from auto zone for $295($59 each). Try auto zone for your coil pack as far as the other codes I personally have not experience any of those problems...if I were to guess about your p0115 Eng. Coolant temp i would say it probably could have something to do with your thermostat and not allowing your cars coolant to reach a the temp, can you please tell me/us what does your temp gauge read? is the gauge low(below the center mark on gauge)? again I am guessing on your p0115 code and think this could be your problem not 100% sure but it is a place to start and eliminate the thermostat as the culprit...please post your findings, and look at replacing your coil pack...good luck

 

I kicked around the idea of replacing the coil packs but my brother talked me out of it. To his defense though, all the tinkering we've done on my car has been a learning experience as he's never touched a volvo before. I had to order my air filter and plug wire boots because there is no auto store here that has anything for my car. As for the temp. My car has never overheated although when I turn the heater on I smell the coolant. The temp stays about in the middle of the gauage. And the fan comes on after a longer drive. I've taken my car into the shop for a couple things that I could of changed myself and thats why I am trying things out before I do that again and get a big bill on something fairly easy.

I appreciate you insight and will post any results.

 

The ECM doesn't sound good. What would it take to replace that?

 

first, 01 c70 don't run on spark plug wire. they have individal coil. second, aftermarket don't give u the right codes all the time. sometimes they are different from vida which may led u to the wrong diagnosis. third, i m smelling the touble of etm. i m not suspose to say this. but the only true way of testing it is through vida. i m actually saving u time & money by not just throughing parts in your car

 

they is a special tool to re & re the ecm.

 

OEM from IPD can get you the correct parts for your car or you can use the sites sponser fcpgroton, grotton gets the items to you very quick and give you a 10% discount by mentioning this site.....there is Nothing better.

Ibanez is correct, you dont have spark plug wires - the coil sits right on top of the plug....you do however have coil wires, is this what your thinking/referring to as spark plug wires? good luck and keep us posted as to what progress your making! again I would tell you to use the site sponser to order the parts for your car, afterall they do support this forum!

 

The coolant temp code is likely to be a failing coolant temp sensor. If they are like a VW, it makes the ECM think the coolant is wicked cold, and richens up the fuel mixture. This can cause a hard/no start, poor mileage, and misfires with running rough.