Friend of mine has an 85 240 (the one I did the timing belt on), he called me Monday with a problem. His car had what I thought were the symptoms of failed f/p relay. Guy lives about 40 minutes from me, so I ran up there with a f/p relay and it started but wouldn't run for more that ten seconds before stalling.
I jumped the 4+6 fuses. I could hear the in tank pump, but not the main. Jacked it up and whacked the pump it with a hammer a few times (just for encouragement) and it perked right up.
But still the same. What are the chances it is a Fuel pump pressure regulator?
What else might I be missing?
Thanks as always
Paul

Classic symptoms of AMM failure. Pull the electrical connector off the AMM then try starting. The ECU will see the missing AMM signal and use "limp home" mode to run the engine. It should start and keep running, albeit rough, especially above ~2000 rpm. Acceleration will be pitiful, but the car is still drivable in an emergency. Avoid removing/re-connecting the AMM with the ignition ON, too much risk of an electrical arc frying electronics.
--
Dave -940's, prev 740/240/140/120 You'd think I'd have learned by now

The history of the car is needed. Did it sit for any length of time? If so replace the fuel filter and maybe even the two pumps if the filter is full of gunk.

Car has run continually since its last repair (timing belt three months ago).
I am going to "The Ecology Center" this morning and will look at fuel related parts.
The hard part about working on this car is its being 45 minutes away, making it more difficult to just throw parts at it.
I'll let y'all know what goes on as life progresses
Paul

Can you keep it running at a high idle if you give it gas?

I'm wondering if it's not gas related. Maybe faulty AMM

--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html

Called Guy this morning and had him disconnect the incoming fuel line to the FPR
jumping the 4?6 fuse he could hear the pumps running but no gas was coming out.
FWIW for the ten or so seconds the motor runs it is as quiet and smooth as you could want.
I was leaning towards thinking maybe the main pump or its accumulator had gone to hell.
If I am going to replace the AMM I am going to rescue one from a donor.
How can I be reasonably sure it is working?
Paul

Called Guy this morning and had him disconnect the incoming fuel line to the FPR
jumping the 4?6 fuse he could hear the pumps running but no gas was coming out.


Are you saying he disconnected the incoming line at the back of the fuel rail and with the pumps jumpered and no fuel was coming out? If the main pump is actually running and he is not getting any fuel to the rail I would wonder about the filter being able to "pass gas" ie clogged.

However if he was confused and simply pulled the vacuum line off of the regulator and no fuel was coming out then that is a good thing...

Randy

If it runs smooth at all, I doubt it's an AMM issue.
Usually you have to feather teh gas pedal like crazy with a bad AMM.
Getting one from a junkie and hoping it's good is a tough one. The ones I have gotten have been from cars that were running fine before they crashed. There are Readings to supposedly verify they are good but some people on the BB say that they may test 'good' electrically but not work correctly.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html

So as far as the AMM goes what is the range of part number's acceptable for exchange? I will pursue the fuel delivery problem as the current problem.
As it runs briefly and I can hear the in tank pump running, and I had to persuade the main pump to come to life: I will look at replacing the main pump and accumulator. Anything besides not smoking while doing this, that I should know?
Thanks as always
Paul

"I had to persuade the main pump to come to life: I will look at replacing the main pump and accumulator."

1. There is no accumulator in the LH 2.2 FI system.

2. I would not replace the Main pump until making sure it is getting voltage from the fuse 4-6 fuse jumper.

When Fuse 6 (always hot) is jumpered to fuse 4 (where the pump relay normally sends voltage) it sends the voltage towards the main pump.

But on the way, that voltage has to get thru a connector under the left rear passenger seat, where the pump ground is also fastened to the 25 year-old floor sheet metal.

Those under-seat connections are known (if not common) trouble spots.



--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

007 is the only AMM for that car. Any (non turbo) '85-'88 240. Lots of 740s too, though I couldn't tell you specific years/models.

Though like Tony said a bad AMM will not let a car run smoothly. Also, it's more like it dies after one second, not ten.

Sounds more like the car is loosing either spark or fuel. Could be something as simple as a bad distributor rotor. That's the only thing I can remember seeing fail with the exact symptoms you've described.

Best of luck!

Afton
'68 220, '88 & 92 245s, '98 XC 70

O.K.
Once more into the fray
With 4 and six jumped I can hear the in tank pump running
With the car hacked up I can lay my hands on the main pump and feel it running
But there is no gas flow to the fuel pressure regulator
So if this car doesn't have an accumulator, what is that other cylindrical thing on the mounting plate with the pump?

"But there is no gas flow to the fuel pressure regulator"

Tell us how you know there is no fuel to the regulator. It's not that easy to disconnect from the fuel rail, and thus not a typical trouble shooting approach.

I mean no disrespect, but since you were confused about the fuel filter, I'm wondering if you might have been pulling off the FPR's push-on rubber hose by mistake, thinking it was a fuel line? If so, there should be no fuel there on a good FPR. That vacuum hose is connected to the intake manifold to regulate fuel pressure according to engine load.

--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

I'm slow but I'm not that slow.
I know fuel line from vacuum.
I called the filter an accumulator because at some point in time another Volvo pundit called it that, and was not corrected by any of the then current B.Board members. Ergo I called what what my then betters called it.
And yes I disconnected the return fuel line to check the fuel flow. Again I'm slow not stupid.
I am however usually sensible enough to ask for help when needed and available.
Given that I had to nudge the main pump back to life, are we looking at the fuel filter as a probable culprit. What about the stuck pump? I have a pump, filter bracket that should bolt on to Guy's car
Paul

Paul,
I didn't mean to imply that you were slow or stupid. But your descriptions in this thread (and others) led me to think you may not be thoroughly familiar with these earlier 240s. And that made it hard for me to be sure of just what you were doing, given:

1) Your earlier (and unheard of) Crank Pulley experiences:
My son has an 83 240 with the two piece pulleys, (and spacers) which bolt to the harmonic balancer via two studs and four bolts. This will be the third time we have replaced the pulleys and twice we have replaced the balancer.
• The term "Balancer" showed a lack of '83 familiarity, and there is no mention of how the main crank pulley bolt was being tightened. [In another thread you advocate using an impact wrench for loosening the main bolt, with no mention of tightening to torque spec.]

2) The Accumulator/Filter mix up in this thread.
• Not a biggie, but enough to raise questions about '85 240 experience level

3) Several comments here like: disconnected the fuel line coming into the fpr and no gas flow to the fuel pressure regulator. Then today: And yes I disconnected the return fuel line to check the fuel flow.
• Yes, a good system should be gushing return fuel from the return line, but till now it seemed that you've somehow been checking fuel into and to the FPR. Not typical as I said, which prompted my question.

"Given that I had to nudge the main pump back to life, are we looking at the fuel filter as a probable culprit. What about the stuck pump? I have a pump, filter bracket that should bolt on to Guy's car."

From your description the pump sounds like the prime suspect. I'm not so suspicious of the filter, given that the engine did run briefly (presumably while the pump ran). Also, I've never actually had or heard of a confirmed main filter problem.

Be careful with that short line from pump to filter. If possible, pull the tray with pump and filter so you can work on it at your bench, and use your air wrench to loosen the filter Banjo Bolts. Many sad tales here about that short line getting trashed on 1st attempts.

I know it's doubly hard when you have to "commute" to and from the patient, but we'll all try to help when we can.

Press on,

--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

disconnected the fuel line coming into the fpr while # 4 & 6 were jumped.

The fuel line from the tank to the rail is identified in this image. That connection would need to be opened to check for fuel supply to rail.

Randy

Yup, Fuel filter. perhaps that is loaded up.

You can hear the pumps running.... you are not getting gas to the fuel rail. the only thing between the two is the Filter.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html

That would be the fuel filter.