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Loss of power or torque and then a sudden surge

Hi Uncle vova,

Like Uncle Art stated in his prior reply to your question on testing an AMM (or MAF) without OBD or a multimeter, just swap the AMM out with one known to be good.

Then test drive your 1998 S90 wee beastie.

Without using an OBD II code scanning tool to scan for all faults, you'll never be certain your AMM is at fault. The OBD II system on a 1998 Volvo 90 series is far more accurate and less tolerant of system faults than, say, the OBD-1 systems on Bosch LH-equipped cars like my 1990-1992 Volvo 240s.

Locate the OBD-II dongle or connector on your S90. I'm unsure where it is. Like I wrote before, I think it is located behind the ashtray or perhaps accessible through the fuse box. Your Volvo S90 service manual or a Haynes or Chilton manual may provide instruction.

Also look here: http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm#OBDIIScanners

Verify all is reconnected including the AMM.

Call your local Autozone or other parts store. Ask them if they offer an OBD-II code scanning tool you can borrow for your S90 while your S90 is in the auto parts store car park. Scan all codes for all systems, including ABS (why knot?).

You'll then get an indication of the faulty sensor or component.

Clear the codes using the tool. If you have been running your S90 without the AMM connected, you'll for sure receive the fault codes relating to a missing AMM signal.

After the codes are cleared, drive with all connected (don't disconnect anything) for some miles. Then test the codes again.

Many sensors and components may be in a failing or failed state to cause the systems you've described since your problem with the fuel Evap in your post history.

You may also have issues like vacuum leaks, old spark plugs, clogging fuel filter, clogged air filter, and so much more.

Are there any 1996-1997+ S90 V90 owners that can help Uncle vova out here? I'm a little out of my element here. Not laid hands on an OBD-II 960/S90/V90 in quite some time.

Questions?

Comments?

Holiday Pie Season Recipes?

Hope that helps.

"Buttermilk" MadcDuff.
--
Mmm-mmm! Parsnips!






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New Loss of power or torque and then a sudden surge
posted by  vova subscriber  on Thu Oct 18 10:53 CST 2012 >


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