I've read through the FAQ and lots of searches but can't find what I need. I'm having some issues with my 1993 240.

Thanks to info and input from this forum I was recently able to install a new head gasket, had the head machined, new timing belt, water pump, drive belts, new air box and filter, new coolant hoses, etc.

Now on to my current issues.....

I've had connection issues with the number 6 fuse (main fuel pump). I have to twist it frequently to get the turn signals to work and replace the fuse every couple of weeks or the car won't start sometimes. It died going down the road one other time a few months ago and I solved that issue with a new 16A fuse in #6.

Last week, my wife stopped to get gas, filled the tank at our normal station and after filling the tank the car would crank and crank but no start. After leaving work to pick up her and kid I did the normal checks but couldn't find anything and towed it home with a strap - very close to home so short tow.

I checked spark on all four plugs and there is a strong spark. The main fuel pump turns on with the key. After a lot of cranking with no luck I jumpered the #4 fuse to #6 which turns on the main pump. The car started ran for 90 seconds and then dies. This I thought was the fuel pump relay. Got a new relay at a local shop, no time to order an OEM, and it started up and idled for about 5 minutes, then died. I was stumped.

The next day I cleaned the connections on #6 fuse very well, popped in a new fuse. I checked over the engine compartment thoroughly looking for a wire or vacuum hose that may have become disconnected. Especially since I did the head gasket about 2 months ago. - no luck.

I re-installed the old fuel pump relay and tried to start. It ran for about 2 minutes, then died. I re-installed the new relay and it started up fine. After idling for about 5 minutes and moving up and down the driveway I drove it around the hood. All seemed well, back to normal. So I thought.

Drove to work this morning, about 6 miles away. It started and ran like normal until I got about 100 yards from work and it died going down the road. I coasted into work so I wasn't stranded. After work my wife met me there with our other car to pick me up. I tried to start it and it started right up. We decided to try and drive home, she followed me in case it died. Well, it died after about 1 mile. We used a tow strap and towed it back to my office where it sits now.

I have not changed the fuel filter since I've had the car, I know, probably should have already. I've had the car for about 9 months. The odometer is broken but I think it has about 200k based on the maintenance records and talking with my local volvo shop.

Could this be a fuel pressure issue? One of the pumps or the regulator?

It seems odd to me that it all started when I filled the tank up with gas from less than a 1/8th of a tank.

Anyone with input would be greatly appreciated.

Justin

Justin,

I'm going to buck the logic suggesting you drop coin on a new Bosch main pump. My opinion is you won't find the problem there unless you somehow got some serious sediment along with that gas.

Anyhow the scorched fuseholder is not indicative of excessive current draw by the pump. It is a symptom of windshield or cowl leak and oxidation in the connections right where the scorch mark appears. It is the mark of a 240.

You have the early production '93. In late 93 Volvo moved fuse 6 back out under the hood after 2 prior years on the inside fuse panel.

Before spending money on that much maligned main fuel pump, be sure it is being fed the electricity it needs. Measure the voltage - conveniently under the back seat, when the problem occurs. Blame the pump only if you see 12V or more at the pump when the issue presents itself.

If you see the voltage drop, carefully carefully feel for heat in the wiring around the fuse panel #6. That fuse powers the entire fuel system, not just the main pump. If something is warm enough to make you pull your fingers away -- that is exactly where the problem is -- not in some idea of "excessive current" being used at the load.

I've replaced that fuse with a pigtail blade fuse in the past. The moisture just ruins those fuse panels and the only way to make them reliable again is to clean them like a dental hygienist and load them with only copper and brass fuses. Even then you need to deal with the spade lugs and crimps on the heavier gauge wires leading to it.

All relatively cheap fixes without need to pay back what you think you owe it.


--
Art Benstein near Baltimore

"Doc, I can't stop singing 'The Green, Green Grass of Home.'" "That sounds like Tom Jones Syndrome." "Is it common?" Well, "It's Not Unusual."

Art, I got to thinking. The problem is now persisting to a no start issue all together. The car won't start at all. So there isn't a condition to check to see if the fuse panel/wiring is hot.

I did replace the main pump and fuel filter but it provided no help. The car still cranks and cranks with no starting occurring at all.

I will check the voltage to the pump, which I should have done while changing it, but I suppose it will only tell me if there has a complete failure of that circuit somewhere, not if showing a voltage drop, uncovering an issue in that circuit somewhere. The main pump does kick on when turning to the start position and when cranking.

Justin

When it does not start do you have spark and fuel (wet plugs?
Dan

So the saga continues. I'll try to be brief.

Changed the main fuel and filter on Monday. Nothing changed. I'll note here when I first tried the key in the on position after replacement the main pump did not kick on. There was no click of the relay either. The in tank pump was also not turning on with the key. It was late in the evening and I just put it up to revisit, didn't get back to it until today (Wed).

Tonight I first tried to check the main pump voltage while cranking and wasn't getting anything. I was frustrated to say the least. I had sprayed the bung nut on the gas tank with PB the to get it loosed up so I was ready to replace. I'll note here that there was no indication that the in tank pump was working, through all this I never heard it kick on.

I replaced the in tank pump and sock. Tried to start and no change. Just cranked and cranked.

Removed the fuel pump relay and re-installed. Turned the key and it started right up. I was a bit surprised. Grabbing the voltmeter and getting to the main fuel pump showed 12 volts. It ran for about 5 minutes and then acted like it was running out of gas and then died. I checked the plugs and they were dry. It started back and ran for a couple minutes, then died. I put the volt meter on the main pump plug under the back seat, started it up and watched the voltage as it died. The voltage held at 12 volts, varied by one tenth as it sputtered and died but never went below 11.9 until it died. I think this rules out the main pump circuit issue.

I'm stumped here. I tried unplugging and reinstalling the fuel pump relay and it seemed to work. After doing that the car would start and run for few minutes or few seconds and then die. I thought at first that replacing the two fuel pumps did some good because it would at least start and run for some period every time but by the end, after starting and dieing, starting and dieing several times, eventually the car wouldn't start at all.

I tried to measure the voltage to the in tank pump and it showed 6-7 volts. I wasn't able to watch it as the car died though.

Sheesh, ok. Any imput here guys?

Thanks,
Justin

One other item to note, I did check the spark again and it shows a spark at times that I've checked. I think that rules out an ignition issue. I check all four plugs a couple times.

Justin

OK, not sure how you check spark to be that confident, but it is a fair guess your measurement of the tank pump voltage was actually a measurement of the fuel level sender.

If the voltage measurements you made at the MAIN pump give you confidence that circuit is without defect at all times you still need to explain the scorching to yourself; that you've cleaned the connections there well enough to be able to depend on that being fixed. It sounds a lot to me like you measured it when it was running well. My next step would be to verify fuel pressure at the rail.

I'm going to assume you haven't any way to connect to the rail to measure the pressure, so as a way to learn you probably aren't low on pressure, run the pumps without running the engine (jumper to fuse 4) and give the return hose aft of the regulator a quick squeeze with smooth jaw pliers. Listen and feel. You'll be able to tell if fuel is being returned to the tank, a pretty good indication you have enough pressure in the rail, although not proof.

When you pull the plugs to check spark, are they wet? Have you flooded the motor? Smell fuel in the oil? Washed down the cylinders? Tried checking codes? Tried starting with AMM disconnected?

Be sure when you measure the voltage to the tank pump, you are backprobing the connector where the black wire joins the red/yellow. Leave the gray be. Measure to ground. If you still see 6-7 volts, check at both contacts of fuse 4. Skim through this: In The Tank







--
Art Benstein near Baltimore

A jumper cable walks into a bar. The bartender says, "I'll serve you, but don't start anything."

Hey Justin,

Sorry to hear you went ahead with the consensus above and "dropped coin."

But know you are in good company. Many many Bosch fuel pumps have been changed needlessly.

The 900 series has, in some years, an alternate fuel system using a GM high pressure pump in the tank. That pump is indeed a short-lived example of carefully planned obsolescence, but its reputation should remain distinct, and not be generalized to the 240's very long-lasting and well-built fuel pump.

Many other things could contribute to your hot-fuse-panel morphing into a no-start, but lets move from supposing and planning to actually measuring to see if you have sufficient voltage while cranking. If so, then you can also assume you have enough voltage to run the rest of the fuel management.
--
Art Benstein near Baltimore

Two antennas met on a roof, fell in love and got married. The ceremony wasn't much, but the reception was excellent.

Art, I will check the voltage to the main pump and see if that is possibly the issue here. Thank you, Justin

I'm starting to think this may be a in tank fuel pump issue. It makes sense from the stand point of having issues after the tank was filled up. Plus, the car runs for a short period (so main pump works for a bit) then dies and won't start after the car runs for a while (loses adequate pressure to the main pump).

Thoughts?

I would look at an intermittent problem caused by the fuel system relay or the crank position sensor. Did you tighten un the fuse holder so you are sure you have a good constant pressure on the fuse?
Dan

Dan,

I agree, it's an odd bird for sure.

I did clean the fuse connection and assure the fuse holder is applying pressure.

Maybe I'll try to apply pressure to the fuse with a clamp of some sort while it's running. It seems to start up after I leave it for a while.

I may also try to jumper that fuse connection with clamps and a fused wire connection. Maybe that would ensure a good connection.

One other note, the plastic around the #6 fuse connection (the main plastic frame holding all the fuses) is scorched brown around the bottom of the connectors. Looks like it gets really hot.

Thanks,
Justin

Just squeeze the tangs together without the fuse in the holder.

What about the fuel relay and CPS?

Dan

Dear Boles,

Hope you're well. I usually confine comments to 900 series cars. Unless you have certain knowledge that the fuel pumps have been replaced, I think it is time to replace them. To get 200K from a fuel pump is reasonable. They don't owe you a penny.

The scorching on the fuse holder implies excessive current-flow, which suggests the pump(s) may be "on the way out". It sounds as if the pumps will run for short periods. During that time, current jumps from worn motor brushes to the armature (the part that spins). When current jumps, it arcs. Arcs produce heat and further erode the surfaces, between which the current jumps. Eventually, the gap gets too wide and the device stops working.

If the problem were simply one of a clogged fuel filter, that would not produce over-heating at the fuse-holder. Rather the pump would run strongly, but too little fuel would reach the engine. The pump would continue running, to no avail.

If the problem were one of a failing crank position sensor (not likely, as you get strong spark) that would not cause the fuse-holder to overheat. Rather, the engine would crank - but because the crank sensor's signal had been lost - the fuel pump would not run.

Hope this helps.

Yours faithfully,

Spook

To elaborate further, I suggest first you focus your efforts on the main pump. If the in-tank pump is failing, the car should still run okay until it gets down to about a 1/4 of a tank. At that fuel level the car might sputter etc. but still should run. The main pump is strong enough to overcome a failed or failing in-tank pump and car should still start and run.

Have you checked fuel pressure with a fuel presure gauge? You could also pull a spark plug when this happens and check to see if it is still wet with fuel. If so, you'll know your problem lies elsewhere...

Good luck!

J

Thanks for the input guys.

I have not checked the fuel pressure. A fuel pressure gauge is one thing I don't have in my toolbox. They probably arne't that pricy, I should get one.

I tend to agree that 200k on original fuel pumps is plenty, I wouldn't feel bad if I had to replace them. I should look back in my the maintenance records I have to see if it has every been replaced.

What about listening for the in-tank pump with the gas cap off. If the main pump is going bad, could a weak in-tank pump possibly cause the car not to run?

I may go ahead and just replace the filter, main pump, tank pump and strainer. Only $210 total on FCP and probably knock that out in one day. I just need to get it back on the road quickly.

I'll post back when I figure this deal out.


Please keep providing input if you think we've missed anything here.

Thanks again,
Boles

So far I've replaced the main fuel pump and filter and it did not solve the no start issue. I did put in a new fuel pump relay before replacing the pump and it seemed to work for a short time and then went back to not starting at all now.

I also have a new pre-pump. I'm going to go ahead and replace that as well, just based on the age of the existing and since I already ordered from FCP. However, as this time I'm not very confident this will solve my no start issue. I suppose there could be a vapor lock issue, a clogged filter sock in the tank or an issue with the sending unit hose. Hopefully, i'll know more when I break into the tank after work today.

I've tried to check the fuel pressure at the fuel rail but have been unsuccessful. I don't have a proper fuel pressure gauge. Any input on a fuel pressure regulator failing suddedingly? I would think the spring loaded diaphram would cause rough running issues before it just failed.

Will post back when/if I make progress.

I may be taking this to my local Volvo shop if this pre-pump doesn't solve it.

Justin

Yup, good idea. Take the gas cap off and listen for the in-tank pump running. I guess it's possible both pumps could be failing simultaneously, but I doubt it. Your car's behavior sounds more like a bad main pump or an electrical issue.