Ok, my Volvo S70 non-Turb with 106K miles.

Leaving the house, after 10 minutes of highway driving, I reach a big hill. The car will shake once or twice while going 70, like I ran into something with the Check Eng light flashing at the same time. No code saved.


I am confident it isn't tranny related as if I overcome my fear of being jerked around and give it more gas, it does downshift to finish the hill. And, I believe I understand that the torque converter won't absorb this jerking motion if it is locked.

Just for fun, I did shotgun the fuel pump controller under the fuse panel. But, now I'm thinking the coil module under the ignition coil should go next.

More interesting, if I start the car from cold and am driving on a residential street, the engine dies instead of balks. But, I can restart it right away.

I hate to think I have to keep driving until it fails hard.

1998 Volvo S70, 106K miles.

On a regular basis, but not guaranteed, I have a stumbling problem about 5 minutes into my journey. On side roads, it dies but restarts immediately. On the highway, it hits based on time, not the hill I climb on my way to work.


CEL flashes at the exact moment the car is shuddering but no code is latched.

For fun, and because it was only $50, I replaced the fuel pump controller underneath the fuse panel. Same problem. Flushing the tranny gave me a week of reprieve, but it isn't trans related.


Bought an ODB2II reader (Innovan 3130) First one that supported LiveData I could find.


I noticed Fuel System 1 would start out as OL (open loop) but then switch to CL-Fault. I actually googled closed loop fuel systems and found out it is a Volvo patent that involves regulating fuel mixture by the O2 sensors.

Ok, back to the code reader with Live Data.

(Volvo. WHY DOES A DEAD O2 SENSOR NOT LATCH A FAULT CODE?????? DUH???)

Fuel Sys 1 CL-Fault
Calc LOAD(%) 28.2
ECT(degF) 192
STFT B1(%) 1.5
LTFT B1(%) -3.1
Eng RPM 2940
Veh Speed(mph) 78 (it shudders less at faster speeds. That's my story)
Spark Adv(deg) 27
MAF(lb/min) 4.513
TPS(%) 25.0
Air Status OFF
O2S B1 S1(V) 0.705
STFT B1 S1(%) 2.3
O2S B1 S2(V) 0
STFT B1 S2(%) 1.5
OBDSup OBD & OBD2
PTO Status ON

I would start by cleaning the throttle body. The blinking CEL can be tranny related, have you flushed it yet? I guess you replaced the timing belt and tensioner at 105K.

I suggest you get a good code reader and plug it in, then when you are not in bumper-to-bumper traffic and you get the blinking light of pending doom, the code reader should come up with something useful.

Klaus
--
Two great Volvos, a 1967 220 and a 1998 V70R

I had the Volvo dealer flush the tranny at the last visit plus oil change. I had them do the recommended service including belt and tensioner at 93K miles due to its age.

They couldn't reproduce the symptom last month. I'll get a code reader.

The vehicle is still in good shape. But, I strongly suspect I have the original ignition coil plus the module connected to it.

Thanks!