740 lumpy idle

Evening all ! This is my baptism of fire, so to speak. I have just taken delivery of my first Volvo, an immaculate 740 GLE with 130,000 on the clock. It starts and runs really well (asnd the body-work is also remarkable). But the petrol pump occasionally makes a low unobtrusive whiring sound at idle. Also the idle is not smooth. When warm the engine is quite erratic, not smooth at all. May I ask if anyone thinks these two symptoms are related. Or, is this a common fault with the 740, please? any ideas, guys? Best wishes Arty

Reply to
bodacious
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Arty, you probably need to do an inlet tract (filter to inlet manifold) including Idle Air Control Valve cleanup. This is needed every two years for the engine to have the best inlet conditions for satisfactory running. When thoroughly cleaned reset the slow running speed and throttle switch if necessary. The pump may be responding to possible in-tank pump irregularity. Unless your car has Regina/Rex fuel ignition system there are two pumps fitted, one in-tank and one main (underneath car under passenger seat) presuming you to be in UK. If Regina/Rex then there is only one pump which is of in-tank variety but much stronger than two pump in-tank pump.

You may also need to check the condition of the ignition set-up.

Good idea to join the Volvo Owners Club, check out details and joining instructions on the website URL is

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when you receive your goodies package you will find a form for registration of your car to the register below.All the best, Peter.

700/900/90 Register Keeper, Volvo Owners Club (UK).
Reply to
Peter K L Milnes

I can't speak about the possible fuel pump problem, but...

I recently tuned up my 740 GLE (125k miles). It was only getting

16mpg, had a rough idle, plugs were terribley fouled with black carbon soot, and I could feel the engine miss all the time.

I replaced distributor cap, rotor, and plugs. Adjusted the Air Mass Meter flap, and the idle. It runs much smoother now, and gets 23.5mpg in mixed city/hwy driving.

I also recommend cleaning the throttle body (carb cleaner, clean lint free rag, toothbrush, and new gasket). The Throttle Position Switch is plugged into the throttle body, and probably needs replaced, if it never has been.

Regards ~

Reply to
Jason

Many thanks to you both for taking the time to offer good advice. This morning I had the injectors replaced by the local main-agent Speeds of Nottingham, (£60 per hour BTW). I think the prob is cured but I'll bare/bear (?) in mind the other suggestions. Many thanks again Best wishes Arty Scott

Reply to
bodacious

Reply to
John Robertosn

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