I've had a number of similar issues lately. Now the main fuse has blown (the one in the engine bay), and the plastic fuse holder has completely melted.

I've bypassed the main fuse to test the following:

Both fuel pumps operate with #4 to #6 fuses jumped.
Both fuel pumps operate when turning the key to "on" -- the fuel relay clicks (it's new)
I've had a replacement ECU for the past couple months (the old ECU had to be replaced because the fuel system wasn't working).

Any ideas?

 

those fuse holders get hot and melt when the contacts inside them corrode.

just pick up a marine fuse holder like ...

and splice it in place of the old one. I recommend putting a good coat of dielectric grease on the fuse pins before plugging in, to keep future corrosion at bay.

 

Hi Pierce,

I should have specified more clearly. I have a replacement fuse holder (the same one you linked), but I wired it up and it didn't work. I removed it, then just joined the two wires together thinking the fuse holder was bad. It wasn't. Still won't start.

 

then you need to go down the whole standard troubleshooting tree... your car has Bosch LH 2.4 with Bosch EZK ignition, so the info on the 740/940 FAQ is helpful, there's only a few minor differences
https://www.volvoclub.org.uk/faq/Eng...injection.html
https://www.volvoclub.org.uk/faq/Ele...lIgnition.html

major differences between an 89+ 240 and a non-turbo 940 are ...
1) 240 does NOT have a ''radio suppression relay", so you can ignore anything referencing this
2) 240 fuse panels are quite different than 940, and the relays are scattered all over behind the dash, while on a 940 they are centralized in a relay panel

 

I used the onboard code reader, and there were no faults. This video helped:
Injectors fire, pumps work, fuel is getting to the rail.

I pulled the #1 spark plug out, cranked, and there was no spark. Then, I pulled the connector that runs from the coil to the distributor off, and checked spark there. The coil is producing spark (big spark), but there is no spark at the plugs. I checked the distributor and wires, and they look a little corroded but nothing major.

Coil could be bad even though its got spark? Worth replacing the ignition module? Crank position sensor? Cap, rotor, wires, plugs?
Any thoughts?

 

if there's spark on the coil wire but not on a plug, the onlky thing in the middle is the distributor. did you check the condition of the cap and rotor ?

 

Yeap, it doesn't look too bad. As I mentioned, it's a little corroded, but I've seen worse.

I'll replace it and see what happens since it's cheap.

 

So I re-tested for spark at the plug, thinking I may have not had it grounded correctly. Sure enough, there is spark. But, it won't start.

So far, spark and fuel check out.

Would a crank position sensor be a culprit?

 

spark, fuel, compression, timing.

a bad CPS would mean no fuel OR spark.

have you verified that the timing belt is intact and the timing isn't way off? quick method verifying the belt isn't broken is to remove the oil cap, look at the camshaft inside, and have someone crank the car for you. also pull the distributor cap, and verify the rotor is rotating.

 

I will check timing. The rotor turns.

Just to recap, the car died while I was driving it. It was similar to when my ECU crapped out a few months ago. This time, however, the main fuse blew.

 

Just to recap things so far:

1. Fuel - both fuel pumps are working
2. It has spark
3. It has compression
4. Timing belt is intact (cam and rotor turn)
5. Fuel pump relay works
6. I replaced the ECU several months ago when I the fuel pump circuit was not working: a used 0280000933 -- car ran fine after this, but I did notice the idle was high and the in-line fuel pump was extra noisy...

Could my replacement ECU be the problem? The fuel pump circuit works with it, but perhaps there's a different issue with it?

Thanks.

 

if the fuel pump is powered, then the ECU is doing that part of its job. if the pump is noisy, either the intank pump is dead so the main pump is working twice as hard, or the main pump is dying.

 

Main pump and in-tank both function. Main pump has always been noisy since I purchased it, so it could be on it's way out, but it works.

Again, going back to the first issue -- the main fuse blew. I suspect that it would be either of the pumps or the wiring that would cause this issue given that there don't be seem to be other issues.

I would expect that with both pumps working that it should at the very least crank over.

 

the main fuse powers the whole fuel injection system, including the injectors, the ECU, etc. most of that power goes through the fuel system relay, which has two parts, one half switches on power to the ECU and stuff, and the other half switches on power to the fuel pumps.