dear Honestjohn,
I own a G-plate Volvo 340 1.4 with 112000 miles on the clock. The engine seems generally sound but has recently started cutting out on decellerating: approaching junctions etc. This is worst after periods at high RPM. Once the car is restarted the problem generally clears for a few minutes before reoccurring. Any ideas at all?
Many thanks
Ollie
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Sounds like carburettor icing, caused by the flexible hot air pipe from the exhaust manifold to the air intake being either damaged or missing altogether. Probably the icing is not bad enough to cause significant loss of power at large throttle openings, but just enough to block various jets and air passages at idle.
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Thanks Richard,
Further to the last, the problem of stalling at junctions is partially alleviated with significant choke.
On a slightly different subject the fuel consumption is horrendous ~250 miles to the tank. Heavy car, small engine I appreciate but is this normal?
Thanks again,
Ollie
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My old 340 1.4, 3 door 'G' reg did 200K miles and returned around 40mpg.
However, it got alot of TLC with regular oil/filter changes at 6K periods. Regular tuning etc. I found the ignition system had to be kept clean at all times the plugs and leads did not like oil or water contamination, wipe down with a meths soaked rag. The distributor cap and rotor arm frequently needed the condensation removing. One problem from early days was similar to the one described. An AA man advised that it was a good idea to permanently secure (using a self tapping screw) the carb. air inlet thermostatic valve flap into the position that supplied only hot air from the manifold and yes the flimsy air supply pipe is very prone to failure. I found the car ran OK both in summer and winter. One other point, you might look at is the idle shut off solenoid on the carb. £35.00 from Volvo about £15.00 from the independents, this has a habit of failing intermittently.
I never came across the other faults but the carb was prone to loosening up and needed a tighten up every now and then. On other tip, soak the carb. and jets in Redex. Cleans things out.
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Also check operation of flap to select hot or cold air. On MKII Golf this was controlled by a vacum pipe, operation can be checked by sucking (clean it 1st though) on the vacum pipe (The hinge on my Golf's flp had corroded and the flap would not work, snapped it apart sanded the pivot bar reassembled and it worked 100%)
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It could be burning heaps of oil on the over-run, fouling up the plugs, if valve stem seals are worn. Can you see behind when slowing? Otherwise, I'd think carb.
Mike
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I'd be looking for a blocked/part blocked idle jet.
Had this on a Granada few years back after it had stood for six months. It was a regular thing for it to cut out or only just keep going as you slowed to a halt. Made worse by being an automatic.
Those idle jets were easy to pop out and I had the routine to clear them down to a fine art.
Having said that nearly any problem affecting a car can be worse at idle so all the basics need checking.
Plugs, leads, rotor arm, dist cap, points (?), timing, carb mixture/idle speed, air filter first then start to look for a specific fault.
David
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That's given you some ideas then. The garage at the east end of Greetham village might look at it for you. Leave the A1 Northbound at the Ram Jam and follow the sign towards Secret Lincolnshire Airbase - garage is on the left just after a pub, as you come into the village. Good luck!
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Ollie,
As well as all these valuable suggestions, bear in mind that this engine regularly shakes the carb to bits - literally, the top of the carb comes loose on the body, allowing improper passage of air and fuel in all directions. New top gasket required, with a tiny touch of Loctite on lid srews on reassembly.
This engine also very prone to induction air leaks between inlet manifold and cylinder head. Try spraying in this area with carb or brake cleaner - any change in engine tone/revs indicates a leak. Only cure is a new inlet/exhaust manifoold gasket - use new self-locking nuts, and ensure mating faces are clean and flat. Odds on to a bent penny the brake servo vacuum hose has imploded where it fits to manifold, but this is not connected with immediate problem.
Have fun, Adam
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