1995 T-5R Hesitates on light acceleration

[Atis]

I do not have SAS either, and yes I meant that check valve just right between the intake manifold and the EVAP valve (for me the stuck-open EVAP did not caused any hesitation...).

Without a code it will be hard...

You have to make it kind of a systematic, I mean to rule out possible root causes one by one.
I would start with new rotor/cap/wires/(?plugs?), as they are really old anyway and can cause hesitation.
Beside that to make a smoke test (or boost leak test), to rule out any leaks in the intake side.
From sensor side check MAF or maybe TPS (for MAF I do not have clue how to check... ).

[Ben850]

My '93 has only OBD I. I did not get any codes. Replacing the front O2 sensor made all the difference.
It may work for you as well.
If it is within your budget, I would do that. If it hasn't been replaced, a 19 year old car could use that part.

[chrillew]

Is there any date that u can check on the sensor? Well i found a good price on fcpeuro. http://www.fcpeuro.com/products/volvo-o ... -v70-15097

If this is the correct sensor for my car.

I searched a bit on troubles with o2 sensor, and it seems when its not fully broken it can do things like this. so if its outdated and been there since 1995 probably should change it. the interval is i think 100k miles? mine has soon done 200k miles

[erikv11]

That's the right sensor. And a good price from a good vendor, nice find.

[precopster]

I hate throwing parts at a car. I only use readings from scanners (particularly live readings) when it comes to expensive items. In my book anything over $5 is expensive.

[Relaximus]

I had a similar problem with my '95 850 Turbo. It would stumble slightly under light acceleration, but be fine under heavier throttle inputs. My problem turned out to be a dead-spot in the TPS. Pulled the throttle-body and cleaned it and the IAC and replaced the TPS. I also cleaned the MAF sensor, but that was more for maintenance as it wasn't the source of the problem.

Dave

[chrillew]

Haha, i cant do live readings and it´s a pain in the ass, so its normally u just live with it until it breaks or show signs. in this case it can be so many things...

Well, i changed all the vacuum hoses now. looked up the distributor and rotor. they looked bad, last year they looked ok. so im gonna sand it carefully and order new ones. also cleaned the rpm sensor on the gearbox. so i will write later tonight if it has done something or not.

[precopster]

Good move on ordering cap and rotor. Our rotor button went bad on our '95 850 a couple of years ago. It would intermittently cut spark and cough and splutter. The meter test showed 2K ohms across the tip to centre which is normal however it broke down when warmed up.

A $10 part left us broken down one night.