My wife broke down last week and I found that I had a code P103 which I replaced the Mass air flow sensor, five new plugs, cap and rotor, and a fuel filter. After three days I know have the same code andP0243 code.The car wont idle and then clears up. I cleared both faults start driving, car runs goodand when I get on it I feel a shutter and the engine check light come back on with both these codes.

Any ideas? Also what does CBV mean?

1998 T5 S70

Thanks for any help,

fgm

 

CBV is your cycle bypass valve, also known as a BOV blow off valve, except it cycles the air back in instead of letting the air out. It may be possible that your CBV is not functioning properly, I am not to technical on volvos or any car, but if the CBV is not working, then the excess turbo pressure it gonna go back and hit the turbo(Bad[:@])
HKSsome info, some sales pitch, but you will get the point)
"The primary function of any blow-off or by-pass valve is to prevent compressor surge by relieving the compressed airflow that reverses direction as the throttle is closed. HKS blowoff and bypass valves reroute the pressurized air, that is normally forced backwards into the turbo compressor, into the intake stream or by venting it to the atmosphere. Subsequently, engine performance is then increased from quicker turbo spool up, as the compressor speed is not reduced by the backward airflow. The longevity of the turbo is also increased, as its bearings will not suffer from the impact that is also produced by compressor surge. Though many vehicles incorporate factory by-pass valves, they are often undersized and quickly are beyond their capable operating range as airflow levels are increased. "

 

Thanks for the info, but I can not believe that I have a problem with the turbo system yet. The only code that came up before all of this happened was the mass air flow sensor, the car would not even run. I replaced it and it ran good for two days, then one of the new plugs I replaced was dead, replaced the plug the car ran good for the rest of the day and now this. The last reset I did to the codes comes back to the mass air flow sensor again. Thinking about changing out the air filter whch is only about 7 months old and trying this again.

fgm

 

How about the ignition wirs?
Are they original?
If they are they might be bad.
They usually only last about 5 to 10 years. You are at 9 or 10 already.(If they are original)

 

The ignition wires are original. Do you thing this might help?

fgm

 

Does the car hesitate under boost?
Does the check engine light flash under hard acceleration?

 

yes seems to be doing both now

fgm

 

I am off to buy ignition wires before the store closes, it Saturday. Check in when I get back.

fgm

 

Tech,

I just got back from picking up my parts(wires and another map flow sensor) I got two faults while out.While driving on a side road slowing down to stop at a stop light I got P0203 Map sensor, reset it and cleared. On the way home,crusing at 68 MPH on the high-way, I got the second fault, showed both of thesecodes. P0203 and P0243. Both times the car fluttered, it did not stall.

Do you thing that the spark plug wires would help? Or should I change both the wires and the map sensor again. I have a warranty on the map sensor but I really do not want to change this unless it could be bad.

Thanks for any help,

fgm

 

I replaced the wires seemed to run good and then car shuttered again followed by check eng lightand a code P0103.

Iwill grant this, all that I have replaced needed to be replaced due to mileage 93,366.00 anyway. There are no signs of a vaccum leak. Engine idles smooth.

Here is a list of what has been replaced

Plugs
Cap and rotor
Wires
Fuel Filter
Air filter
Mass Air Flow Sensor


What to do next, I am about to give up.

fgm

 

Reset the codes one more time. I drove the car yesterday after noonno faults.A couple of more days will let me know if the wires corrected the problem.

fgm

 

Did you try the second Mass Flow sensor yet?

 

The car still continues to stall at idle and while running around town. Code P0103

Not sure what to do at this point.

fgm

 

Was that with the new replacement mass flow?

 

I believe the mass air flow is a rebuilt one (Bosch) theauto store does not stock new ones. The problem is intermittant, stalls a light whileat idle, flutters at approx 30 MPH, code still showing P0103 which goes back to the air flow sensor.I was thinking about the water temp bulb, noticed water temp climbs to temp very quickly. What do you thing?

 

What year is the car?

 

1998 S70T5

 

Seems fishy that the temp climbs high.

When it goes to stalling does it ever happen on the highway?

If it does what does the tach do when it stalls?

 

Temp runs high I was just guessing that it might be given it a bad reading. I just changed the mass air flow sensor again(warranty) since it is covered, now the car won't stay running and it flags the air flow sensor again. I do not have the other sensor because of the exchange. I am loosing it now.

 

Hmm maybe the new one bad.

Will it run at all with it unplugged?

It will go into limp home mode with it unplugged.
It should idle smooth.