1988 244 DL N/A with about 300k miles.

History:

Driving today, it started stumbling. I pulled over, turned off the engine, and looked in the engine bay. Nothing stood out. I resumed driving. About 1 mile later, stumbling recurred. I got a tow home, car pointing up-hill. No start.

What I did:
Battery charged to 12.6 Volts. No start.
I felt the main fuel tank vibrate on turning key to "on" position; it did not sound unusual
Noid tester showed power to all fuel injectors
spark tester showed spark to all spark plugs
spark plug 1 sampled; dry and clean (just changed 100 miles ago with NGK copper)
2 Ohms resistance at fuses #4 and #6
No sound from inside fuel tank at gas fill area

Gas tank less than half full. Filled to 3/4 tank. Car started right up.

Tested wiring to in-tank/pre-pump engine idling. No current at black sheathed brown and gray wires (ammeter used). Backprobed at wire harness to test voltage. 12.76 volts between wire harness black wire and brown ground (which came from in in tank fuel pump). Only 7.1 Volts between the the black wire and gray wire that have the black sheath. I cleaned the ground and found only 1.2 Ohms of resistance between another bare metal part of the metal trunk 6 inches away and the wire.

Is the in-tank fuel pump bad or is there a problem with the wiring?

What do I do next?

How do I disconnect the black plastic wire harness plug that feeds the in-tank fuel pump?

Thanks

Hi,

Try this article from Art.

It’s got pictures and fun things!
(:)
http://cleanflametrap.com/transferPump.htm

Phil

Thanks!

Delphi FE0071 is OEM and unlike FE0069 has up to 8 Amps capacity. Bentley says that 1986+ use 3-4 Amps. Am I correct that FE0071 is the right part? Can I go wrong with Delphi instead of Bosch, which costs twice as much?

Oh yes, yes you can go wrong with a Delphi pump. Had one bad out of box, another lasted two days. Don't know who makes a good one, but I don't recommend deplhi.
P.S. Test it before install.

Get the US-made Airtex E8778.
If Bosch is putting their name on tank pumps for the 240, they probably just bought one of the offshore factories. Bosch never made the 240 tank pumps for Volvo.
--
Art Benstein near Baltimore

Have an awesome day and know that someone has thought about you today...I did.

Thanks.

I tried to remove the black wire harness that connects the black and gray wires, but can't separate it. I stopped, because I don't want to break it (out of frustration). Any tips?

"I tried to remove the black wire harness that connects the black and gray wires, but can't separate it."

I'm not sure I'm understanding your question. Let me guess. Are you trying to remove the connector pins from the connector housing? Or are you having some kind of trouble disconnecting the tank sender harness from the wire harness coming from the front of the car? Or what?


--
Art Benstein near Baltimore

Always use precise language and be guided by observed fact. -- Isaac Watts

If I only need to replace the in-tank fuel pump and not the sender, I don't think that I need to disconnect the black wire harness. Instead, I just need to disconnect the leads to the in-tank fuel pump. Is that correct?

You don't need to touch the sender/its wiring unless you're having fuel gauge problems.
--
82 242-6.2L; '17 Mazda3; '16 Crosstrek

Thanks.

That's the part in question.

Before I posted this query, I saw a YouTube video, which I can't find, where the present inserted a screwdriver to separate the halves. I couldn't do that. Is that the correct procedure, THEN stick the pick in the fuel pump end?

Also, in your link, you showed a replacement lock ring, but I didn't see a discussion about when to change it. What's your advice?

Thanks

If your car saw a fair amount of corrosion/debris, then replacing the locking ring may help re-assembly. If things are relatively clean - as mine was - reuse is possible.
--
82 242-6.2L; '17 Mazda3; '16 Crosstrek

I would consider replacing the oring seal.
Dan

Agreed. When I did mine on my 90 I replaced the seal but not the the ring.

Also, as mentioned earlier in this thread, it is good practice to replace the the small hose and the “sock” while you are in the tank anyway. The hose in particular has been known to be problematic.

--
Will I buy another Volvo??? We'll see....

If you really want to test the pumps, I'd separate your wiring/harness testing from your pump testing. Disconnect the connectors for both pumps (inline connector is under the rear seat). Jumper 12V+ from the battery and connect to a known (test it!) good ground nearby so that you're powering the pumps directly INDEPENDENT from the upstream parts of the harness/system. That will let you know if the pumps run or not. Then, as you have done apparently, check the harness at the plug to see if voltage is arriving under the conditions it should be arriving. You should see 12v+ show up as the ignition is keyed "on" (or run if you like) and then drop to 0v after a second or two when the system shuts down the priming party because the engine isn't running/turning over. If that all checks out, you may still have to pull the intank anyway to verify condition of the probably-crumbling short, submersed hose that connects the pump output nipple to the metal fuel line all of which lives inside the tank. If you have a problem with the hose, and you're keeping the car, seems silly not to go ahead and replace the intank pump as well.
--
82 242-6.2L; '17 Mazda3; '16 Crosstrek

Hi Michael,

Running power directly certainly makes things more simple to understand.

"You should see 12v+ show up as the ignition is keyed "on" (or run if you like) and then drop to 0v after a second or two when the system shuts down the priming party because the engine isn't running/turning over."

There's no "priming party" in the NA 240s 83-88.

--
Art Benstein near Baltimore

'I've had bad luck with both my wives. The first one left me, and the second one didn't.'
James Holt McGavran

Thx Art - assumed it worked like 5.0L system did. So the pump doesn’t run til you turn it over?
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82 242-6.2L; '17 Mazda3; '16 Crosstrek

So the modern cars do this too? It is so easy to do in software, it would make sense to me if it became as standard as the safety practice of shutting the pumps off when the motor is not turning. Very handy for troubleshooting.
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Art Benstein near Baltimore

To write with a broken pencil is pointless.

Hi Art,

I agree, but am somewhat confused because the OP reports in his initial post that the main pump " vibrates and sounds normal with the key on ". Perhaps the test was done with the engine cranking ?

Peter

Hi Peter,

Can't say for sure the OP is mistaken because the individual car may have been modified, but as built, the LH2.0 and LH2.2 fuel system used in the 240 doesn't engage the fuel pumps until ignition pulses are present on pin 1 of their ECUs from the Hall-effect distributors.

The LH2.4 system revives the one-second key-on pump run which was first introduced with the K-jet's electronic relay as a by-product of its missing-pulse design. My guess is it was so handy as a troubleshooting tool, the firmware included it when LH2.4 was implemented. It certainly isn't necessary to prime the fuel rail, but for sure a bunch of folks believe so.
--
Art Benstein near Baltimore

Two secrets to keep your marriage brimming
1. Whenever you're wrong, admit it, 2. Whenever you're right, shut up.
-Patrick Murra

Added gas at 1/2 tank. Remove prepump. Replace short hose on pump assy.

Thanks. Do you mean the sock that goes over the base of the pre-pump?