Hello Gentlemen, I have an 86 740 wagon that has started idling rough. It still runs fine but the exhaust doesn't smell right and it seems like the timing is advanced. I would normally suspect a vacuum leak but I couldn't locate one. Does anybody have anybody have any ideas?

Thanks in advance.

Nick

 

Hi Nick, welcome to the forum.

Is it missing? When was the last time you had the car tuned up? Plugs, wires, clean throttle body, check the intake hose for cracks or holes?

 

Hello rspi, It is missing a bit and the idle fluctuates but not really bad, yet. It's definitely due for a tune up. I think I will try the plugs, wires, cap and rotor and see if that helps. What's the procedure for cleaning the throttle body?

Nick

 

I would do one at a time unless you know the wires have more than 10 years or 100,000 miles on them.

I use to have to clean my flame trap and throttle body no less than every 10,000 miles. I use to drive about 4,000 miles per month on my car.

To clean the throttle body I use to pull the intake hose, unhook the throttle linkage (be careful not to adjust it), pull the 4 bolts that hold it on, and spray the heck out of it with throttle body cleaner. Mine use to stick a little when coming to a stop at lights and stop signs.

 

I'm pretty sure they have at least 10 years on them, plus it has been the runaround spare car so it's been neglected except for oil changes, air filters, brakes and tires. Thanks for the information. I assume there is no gasket involved with the throttle body R & R?

Nick

 

Yes, there is a gasket that should be replaced when you remove the throttle body. This is it here:

Volvo Throttle Body Mounting Gasket (740 760 940 240) - Elring 1271488 | FCP Euro

 

I rarely changed my gasket.

 

Thanks. I ordered one just in case.