When last I posted, I was in the process of having a 1997 70K mi S70 engine put into my 1995 850. The transplant was successful. New Bosch rotor, cap, plugs and wires, all new fluids. Good compression -- within spec for a car with less than 100K.

The problem I am having is acceleration. The car is as slow as it was when the original engine went. Put on the AC and acceleration over 60MPH is a joke.

What would you check and replace first? Can you help me prioritize by effort and cost? (I'm doing the work myself)

Fuel filter and pump -- Is fuel delivery a common performance problem?
Injectors -- Does it make sense to replace them? Clean them? Bosch only?
Throttle body -- My Saab needed it cleaned constantly. Should I attack the intake? If so, what pieces should be cleaned or replaced?
General cylinder and valve carbon -- Seafoam thru the intake? It has been a lifesaver for emissions inspections.
Sensors -- Is it possible that the O2 sensor, and all of those various gizmos, could retard the engine?
Transmission -- Anything there that needs particular attention? Is it beliveable that the transmission is eating HP?
Fluids -- Tranny, differential, oil. Could they really cause lag?
Volvo-ness -- I've never driven a non-turbo Volvo with much pickup. Am I just expecting too much from a ten-year-old car? Strangely enough, it is my daughter who is complaining; my son drove it for two years and was cool with it. Of course, he was the one whole let the oil get low and fried the engine. Parenting is always a surprise.

Thanks in advance,
JM

P.S. Just so you understand, I am not so much expecting the car to be a rocket. I don't WANT the car to be a rocket since my sixteen-year-old will be driving it. I just want to make sure that I'm getting good efficiency from the beast.

Your expertise is appreciated.

 

It was Non-turbo correct?

Is there good flow from the exhaust?

 

I would be checking the cat flow. I would think you would be throwing check engine lights like crazy if it were, but a clogged cat would definitely hurt acceleration. - AB

 

The car is a '95 850 with an '97 S-70 non-turbo engine. I can get into traffic with a roughly 10 second 0-60 acceleration time. Once at 60 MPH, I can only get to 70 with any dispatch if I push the accelerator enough to downshift.

Just seems very slow, that's all. As if I had only 100 HP. Is this just what the engine is capable of producuing?

JM

 

If I find that the converter is clogged, what should I replace it with? There are several direct replacements that include the oxygen sensor port in the $200+ range, and several others that are universal without the O2 sensor in the $60 range. Should I try to find a hi-flow cat for this model?

Thanks,
JM

 

You could find a high flow. But try to get close to the $200.00 one.

I have heard of people having problems with the Universal ones.

 

So, assuming that my wweak engine problem may be the catalytic converter, how do I test that theory? Is there a way to assess the flow or pressure drop through the cat?

Thanks,
JM

 

About the only way to tes would be to drop the exhaust and see if there is a difference.

 

Have you checked the ECU for any codes?