I've had this 1990 240 Wagon for about 2 years now and have had periodic but persistent starting and charging issues. Current behavior as such:

Turn the key and everything lights up, radio comes on, I hear the click of the fuel pump relay, and the fuel pump whirl, but nothing else. Try it a couple times, still nothing. Let it sit 10 minutes or so and wammo! it starts like there was never an issue. Seems to do it more often in wet or super hot weather, but that might just be coincidence.

I suspect it's the ignition, but as far as I know, it could be anything. Would a dying ignition go out intermittently?

Here's a list of parts I've replaced so far, most of it by me:

Starter (shop)
Inline Fuel pump and filter
Plugs, Wire, Distributor
Alternator and Water Pump
Battery
Harmonic Balancer (shop)

All those replaced were original parts, so the work needed to be done. The Balancer was shot and seemed to ultimately be the cause of the charging issue, as well as the 6 year old battery. That work was done about 6 weeks ago and all seemed fine, until I had one of these kindsa non-starts the other day and another today.

Any guesses?

 

first thing i would do is check/clean all your grounds, and also check big red wire leading from battery to starter. when engine starts get a multimeter across the battery terminals to make sure your
alternator is putting out at least 13.8 volts at idle.

 

You can try and see if current is getting to the starter when this happens. I'd look at the ignition switch.

 

is it failing to crank over?
yes i would expect a worn key switch would fail intermittently.
likely unrelated but mine had a bad engine ground look for a heavy wire under the alternator, clean battery posts.

 

Thanks for the suggestions.

After a couple no-starts as described, I got a new one.The starter is cranking, spark at the plugs, but no fuel to the rail... or at least I think this is what's happening. This one isn't temporary though, It's been dead for a week now. The pump is new, it doesn't sound like it's turning on, although it's hard to say with the starter blarring on top of it. It's like an electrical gremlin that gets bored with one area and moves to the next.

 

fuel pump relay's go. look under the drivers feet to the left side its sort of uner the carpet if you tug on the cable gently it should emerge.
if the fuel pump in the tank fails it will run ok when tank is full and give issues when gas is low.
i made up a 'relay jumper' with a fuse. out of an old relay. it'll make the main pump run as a test.
i've hooked a small indicator light to the pump leads , in parallel so i can see if it's on.

if you follow the line from the fuel pump/filter to the fuel rail you can uncouple it there. put it in a big jar, crank it but not too long., just a moment. either you have some fuel in the jar or not. that defies safety practises perhaps..a jar of raw gas presents obvious dangers..that line may or may not be tough to undo..at least have a fire extinguisher at the ready and think that through..

you can spray a little quick start in the air ducting,past the air mass meter it should fire and spin up a bit

check the pins and socket of the mass meter for chorroded contacts.

put a plug on the coil by borrowing a plug lead and ground the threads of the plug and check for spark.that shows if you get a spark from the coil.

you can check on the plug wires as normal too..with a spare plug on one lead..

dont make sparks near open gas...connecting a fuel pressure guage is safer..

 

New developments: Had a mobile mechanic come out for assistance.


Pump is fine, I had a spare relay and tried that prior to starting this thread, but the problem seems to be before that as power isn't getting to the fuel relay.
#4 fuse is fine.

Quick start got the engine to sputter.

Ignition coil is fine.

Spotted the crankshaft position sensor which had frayed outer insulation on the wire. . That thing is in an evil place, by the way, much harder to get to than the 7/940s I've had in the past. I swapped it out today and still no power to the pump. The crank sounds different though. Instead of smooth starter cranking, it's kinda galloping like a train, but no fuel.

 

If you jumper fuses 4 & 6 do you hear both pumps run? This site has a procedure for running this test:

In the Tank - 240 Volvo Tank Pump and Sender

If both pumps run when performing this test then try starting the car with them jumpered. If the car starts then your problem is one of 2 things:

1) Bad fuel pump relay. I know you tried swapping and that didn't help. Maybe they're both bad? Try popping the top off of one of them and use a soldering iron to re-flow the big solder joints on the little circuit board. They tend to develop cracks over the years and make them fail intermittently.

2) Bad ECU. Some early LH 2.4 ECUs had a "weak" circuit that drives the fuel pumps. These ECUs had a pink label on it and tended to fail in the manner you describe. Later LH 2.4 ECUs had a white label that had this problem remedied. I forget the part numbers but you can google it to find them. I always thought that the pink label ECUs were mainly on the '89 240s but maybe they spilled over into '90. Check to see what you have. If it is a pink label you can probably source a white label version at a junkyard. Just make sure you get the LH 2.4 ECU.

 

One thing that might give a clue about the ECU: I've tried to run ODB codes, and pressing the button will light the LED, but it never responds with a code. The only time it lights is when the button is pressed.

Mechanic checked the spark at the contacts in the plug for the pump relay and got a very weak signal, which is what led him to think the problem is before the relay.


It is indeed pink

 

The ECU will not throw a code when the circuit to the fuel pump fails. It mainly throws codes for emission related problems. Check the solder joints on the relay but my bet is that the ECU is failing. It would be wise to locate a white label ECU for the LH 2.4 Jetronic fuel injection system. Google "Pink Label ECU Volvo 240" and you should be able to find enough information to get the correct part number.

 

Zlornick, re ECU, this might help,

Volvo ECU Page

 

Thanks. I had to send a totaled 940 to the junkyard before getting this car. Had I known, I would have grabbed the ECU out of it!

I'm really close to giving up on this project, it's been a never ending string of headaches, and I've reached the limit of patience. The ECU might solve a couple problems, but certainly not all of them.

I've looked at a couple forum classifieds but they are pretty dead. No junkyards around me, unfortunately. If I were still in the SF Bay area, I would have several pick n pulls to sift through.

Any reputable sources other than Ebay?

 

rock auto ?

id examine the fusebox, it comes out with 3 screws unhook battery pull them all.
check if all the fuses are clean scrub it clean, check each spade connector by pulling it off. ive seen those connectors and ends of wire at the fuse. loose contact generate heat, loose sping tension, blacken or turn green. slippery slope..

shine it all up, wire brush,put dielectric grease , light coating. renew fuses.the one near the coil too..

make a drawing if you like and only pull one wire at a time. take pics..

I think this will be a cheap repair, just need to be patient with electrical troubleshooting keep testing what you can.you`ll get it.
you already narrowed it down.

make sure you follow the code reading instructions.exactly.. maybe you didnt plug in the jumper, push the button for more than one second and have key in right position.etc

if you are inclined you might swap the capacitors in the ECU

i got a rebuilt one for my ford van of same era from rock auto. it isnt necessarily the issue though.

is the pump running? has it got power at the leads to it ? id elliminate that question with a meter. you might need toprobe into the cover of the wires with a pin. or make a splice or drop the pump..or follow it back to where you have access maybe under the carpeting..