where is the fuel filter& why bogs out when I step on it?

jaydeevy · Post by **jaydeevy** » 28 Jan 2009, 14:35

I've looked up and down my 81 240 and I can't find the fuel filter. Also when ever I push down the pedel it bogs out but if I pump the pedal and get the rmps up it's fine. I've tweeked the idle but the problem persist.

Post by **billofdurham** » 28 Jan 2009, 15:47

Welcome to Matthew's Volvo Site.

Which engine is fitted? Carb or fuel injection? I would assume carb as you 'tweaked the idle'. Which carb?

Bill.

jaydeevy · Post by **jaydeevy** » 28 Jan 2009, 17:38

It's the SU-HIF6 carburetor.With the B21F engine. The car also ¨diesels¨ when I shut it off. Also I have a vacume line near the battery that is not connected to anywhere and has a bolt screwed into it. Was like that when I bought the car. Was wondering if there was a diagram for the lines because the hanes manual is to vague.

Thanks Again,
Jason

Post by **billofdurham** » 29 Jan 2009, 12:22

The only filter Volvo put on that model was in the fuel tank on the fuel gauge sender unit. This filter had to be cleaned or renewed every 6,000 miles as part of the service. Although fairly easy to do it was usually neglected - 'can't see it, don't do it syndrome'.

On my 240 there was an in-line plastic filter between the pump and the carb but this was put on by a garage to keep the carb free of sediment.

If the filter is partially blocked it could be the cause of your problem but also check:
the piston/needle in the carb is not sticking;
check the oil level in the carb dashpot is not too low;
check the free play of the damper piston on its rod.

I am having problems finding a vacuum line diagram but I haven't given up hope yet.

Bill.

jaydeevy · Post by **jaydeevy** » 29 Jan 2009, 17:10

So do I gotta drop the tank to clean this fuel filter? What about the dieseling problem? Also do you know about any performance parts I put on this engine? Thanks for all the help Bill.

Post by **billofdurham** » 30 Jan 2009, 11:44

So do I gotta drop the tank to clean this fuel filter?

No! Volvo weren't that cruel in the old days.

Disconnect the battery negative lead making sure that you have the radio code if applicable.
In the luggage compartment lift the carpet and you will see an inspection plate in the floor. Remove the plate to see the top of the sender unit. Disconnect the earth (ground) wire and the lead from the sender unit terminal. The sender unit is held in place by a locking ring which can be taken out with a special tool or by using a piece of hard plastic and a hammer. The plastic is to prevent sparks. Place it in one of the cut-outs in the ring and gently tap it until the ring comes loose. Lift the sender unit out of the tank. It is possible to make the tool if you want to.

The filter is on the very end of the unit. When replacing the sender you need a new gasket.

Dieseling was a common problem on carb engines and can be caused by:

1. Incorrect timing.
2. A carburettor that does not close entirely can contribute to running once the engine is off, since the extra fuel and oxygen mixture can combust easily in the warm piston chamber.
3. An improperly rated spark plug can retain heat and cause the problem.
4. An engine that runs too hot or too lean may produce an environment conducive to allowing unspent fuel to combust.
5. An idle speed that is too fast can leave the engine with too much angular momentum upon shutdown, raising the chances that the engine can turnover and combust more fuel and lock itself into a cycle of continuous running.
6. Hot vaporized oil gases from the engine crankcase can provide ample fuel for dieseling.
7. Built-up carbon in the ignition chamber can glow red after the engine is switched off, providing a mechanism for sparking unburnt fuel. This can happen when the engine runs very rich, depositing unspent fuel and particles on the pistons and valves.

In my experience the most common causes are 1; 2; 3; 4 and 5.

Performance parts are not my speciality as I have never modified any of my Volvos. Many years ago I did help a friend to modify/tune his Austin A40 for saloon car racing but he crashed on the first lap and he 'retired'.

Bill.

LalaFrancoise · Post by **LalaFrancoise** » 09 Sep 2009, 18:09

I have an 82 240 and had taken her to the shop to get the external fule pump changed because she was dieing on me at stop lights. When she'd die it felt as though there wasn't and presure when hitting the gas. The guy told me "there was no room" for a traditional filter so i would need an in line filter instead. I feel like im stabbing in the dark as to what my real problem is (as my car still isnt working!!!!!) I love my sweet little 240 but i feel like an ass not knowing what to do!!!!!!!

jcc · Post by **jcc** » 02 Oct 2012, 15:42

I have a 1982 Volvo 240 DL Wagon. The fuel filter on my Volvo is mounted on driver side firewall upper end. Easy access

Post by **billofdurham** » 03 Oct 2012, 11:56

LalaFrancoise and jcc welcome to Matthew's Volvo Site.

As far as I'm aware the early 240s did have an in-line fuel filter exactly where jcc says.

Bill.