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Discussion Starter · #1 ·
Hi all, I recently got an 82 volvo 240 with 50,000 orig miles and have a few questions. First, It starts hard cold and hot and has a slight hesitation off idle. New plugs, cap, rotor, coolant temp sensor have not helped. o2 is new also. I am leaning toward a fuel press leakdown as it sits. What are the specs for the fuel press? Would it be reasonable to use VW CIS pressures and testing methods? Also, can anyone point me in the direction for body repair panels? One of the wells in the trunk is gone and I was looking for a replacement. Thanks everybody.
 

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QUOTE(82DL240 @ May 29 2005, 06:06 AM)Hi all, I recently got an 82 volvo 240 with 50,000 orig miles and have a few questions. First, It starts hard cold and hot and has a slight hesitation off idle. New plugs, cap, rotor, coolant temp sensor have not helped. o2 is new also. I am leaning toward a fuel press leakdown as it sits. What are the specs for the fuel press? Would it be reasonable to use VW CIS pressures and testing methods? Also, can anyone point me in the direction for body repair panels? One of the wells in the trunk is gone and I was looking for a replacement. Thanks everybody.
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I think by 1982 you have the K-Lamda system, ie still mechanical but with an O2 sensor

first thing to understand is the pumps do not operate until you actually turn engine over, so that is the worst possible time [with probably only 6 volts] to ask the pumps to make up any pressure loss.

the Bosch book lists about 6 areas where you can lose pressure when engine is off so it is 100% certain there will be no residual pressure after say 10 minutes off, AND it is expensive to replace all those elements so best to live with it OR do as I have done and use a spare switch on the dash [I use the wind up aerial one] to do a bypass around the fuel pump relay

so you simply give it a blast for a few seconds to get the pressure back to 70 psi [hopefully] before turning over the engine - my engine starts instantly hot or cold - but there are a few other things I have done to get to that point. Remember this is the SYSTEM pressure - the control pressure is different

people have said here to install a pressure gauge [I assume for system press] and that is good advice but maybe you can simply solve problem and not need to go to the expense [I used $30 oil pressure gauges but you also need to buy proper "olive" connections and T piece to tap into the fuel lines]

anyway there is a lift pump in the tank [to give positive suction to the main pump] and on the fuel distributor there is a simple pressure relief valve hopefully set at 70 psi, ie bypassing fuel back to tank

if one symptom is hesitation then it may be time for a new in tank pump

a cheaper way to simply test all this is yr Volvo dealer will have a gauge made up to test the pressure [and for 4 cyl is far easier to get to than in V6 engine]

anyway try this and report back and if needed I will explain the other aspects of cold, warm up, and hot start problems

remember it IS a good system but like anything needs a bit of TLC from time to time so it is worth learing yourself as a mechanic will simply sack the lot starting with a new $1500 fuel distributor and when that no work, new injectors etc
 

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QUOTE(thomas e. pleasants @ May 29 2005, 09:25 PM)hi ya this is Tom, well lets see did u replace the fuel filter and did u clean out your air intake body and clean out your throtoll senor to

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mine dont have a throttle sensor
[but not sure about the 240 of querist]

is that because yours is turbo?

what does this sensor do?

however yes, fuel filter is first thing to suspect - actually my mechanic for last 100,000 kms used to replace it every 10,000 ie every service, but now with a system pressure gauge on the dash I can see the pressure and it stays at 70 psi well past 30,000 kms since last replacement, but they are not very expensive so if you have no gauge best thing is to replace it just to see if that improves the problem
 

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Discussion Starter · #5 ·
I didn't think I heard the fuel pump kick on when key was switched on. If it doesn't start on the first try it always starts on the second. I have all of the fittings to do the pressure tests but the feul dist is in a hard to reach place so I guess I'll live with it. Fuel filter is new also, but I will try and clean out the TB and intake. Another noob question, what's the deal with twin rubber brake lines? Never seen it before...

Thanks Doc, I know a bit about CIS and the finesse needed to get them running right and I didn't want to go rushing into anything without some ideas.
 

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OK it sounds simply like no residual pressure when you try a cold start so the main thing to check is the accumulator on top of the main pump - this is the analogy of a capacitor in an electric circuit - but if other things leak as I said there will still be no pressure in the morning

so if it starts on second try then no worries but what can happen is as you keep trying it gets to other extreme and gets flooded - ie because there is also a start up injector [ie with electric solenoid] which fires only when you are cranking engine and only if engine cold - it is controlled by that sensor sitting next to the temp sensor on the thermostat housing

also reason why fuel pump not on at start is an air flow sensor [switch] under the main flap of the mixture control assembly [under the fuel distributor] so it needs the actual crank of the starter motor to slightly lift the flap - it is a safety spec added on by Volvo to the Bosch system so if you crash car and ign still on but engine stopped the pump shuts down - cunning heh
 

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Discussion Starter · #7 ·
thanks again doc. I think I'll just live with it. if something gets worse, I'll have to investigate. Any idea about body repair panels?
 

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QUOTE(82DL240 @ May 30 2005, 11:01 PM)thanks again doc. I think I'll just live with it. if something gets worse, I'll have to investigate. Any idea about body repair panels?
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good decision - thats what I did till it got a bit worse [hot starts] and I made mistake of taking to "Cairns Dyno Tune"

2 grand later it was so bad I had no option but to get the book and do myself

as for tyre well - fibreglass kit mate
 
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