This is going on for many months and no one can find the cause. She stalls coming to a corner but starts right up every time, or can turn it on standing still and then she'll like shutter and then die but starts up again. Never dies as she's moving along only when slowing down to stop on the brake. Then doesn't do it for a few weeks then again. They cleaned throttle body cleaned out the oxygen sensor they don't know it can't be the main fuel pump cause it starts up again every time. We also made sure there was enough gas in the tank incase maybe the i tank pump. We are really at a loss and so are the mechanics. One checked the wiring harness and noticed that the car side harness connector at firewall that connects to engine controls wiring harness looked like it could be changed. But Dave Barton who is awesome said that would not help. If any one has any ideas?? Car will sometimes shutters before it stalls but not all the time and again it is when braking not giving the gas .... Help!!! Thanks, lynn

You mention that this happens when- coming to a corner - does it happen if you stop straight?

Could it stall when you use the directional signals?

If so. I would suspect bad grounds.

Things mounted in plastic, like headlights, have wires that go to ground terminals.

things that only have a power wire are grounded by their attachment points.

Don't forget hround straps pn the engine and check any small woter connected to the battery terminals for corrosion.

"Never dies as she's moving along only when slowing down to stop on the brake."
If using the brakes causes the engine to stall, I'd go with Art's suggestion to check the booster and check valve.

You could temporarily disconnect the booster hose and plug the port in the intake manifold. Then run the engine to see if there is idle improvement. Without the booster system involved, braking will require extra effort but at least you'll know if the problem lies there.
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

Some of the 240's had a 25 amp fuse mounted along the inner fender in the engine compartment. I think it's a blade type of fuse. Anyway, that fuse feeds power to the injection system and its contacts have a way of becoming heavily corroded over the years, which can cause intermittent engine conking-out.

According to this IPD part description, it's located on the drivers side of the engine compartment about 12" behind the battery:

http://www.ipdusa.com/products/9394/120789-fuse-holder-25-amp-240

--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (fixed the ignition - now back to the brakes again)

See if you can get your mechanic to make it stall when using the parking brake to stop, if he is able to easily replicate the trouble using the foot brake. Have to consider the booster and its check valve, along with the idea the idle valve could be sticky.
--
Art Benstein near Baltimore

If there are no dogs in Heaven, then when I die I want to go where they went.
-Will Rogers

Three thoughts:

1. How old are your spark plug wires? I had a BMW many years ago that had the same sort of problem. Old, damaged or dried out wires can cause this.

2. Ignition coil is bad.

3. Not sure if 87's have them, but if they do, it could be a bad 20 amp fuel injection fuse or its fuse holder/case. These are located behind the battery along the driver's side fender. My 90 240 had a similar problem. I replaced the fuse and the fuse holder. End of problem...

I agree with the consensus, of the other posters on board, that the most likely cause, is the idle mixture or its air flow. The FPR on the fuel rail will have little to do with it unless it is very hard starting or no power under certain loads.

You said they cleaned the throttle body plate and bore. I wonder as well about the throttle switch adjustment. You see it tells the ECU computer that you want the engine to idle.

The program in there looks at the RPM signal coming from the hall sensor in the distributor and tells the IAC to maintain 750 RPM. I see no problem coming from it as the engine fires right back up.

If there is an additional load of say the A/C, that is taken care of, all in one fell swoop. You did not say if this occurs more often or not with the A/C on or off. It's just a tidbit factor that might twist a diagnosis more towards the IAC not working within its "idling range of adjustment."

You cannot have the throttle plate to far open first of all.
It needs to be on the throttle stop and the plate sealing off the bore but not binding due to the return spring pressure.
The switch must be clicked when the plate is at rest closed. The switch must click again as soon as the plate wiggles to open but only move the least little bit.
When that plate open air is allowed around it whole outside diameter, of which is actually a lot area that supersedes the IAC flow very quickly.

Upon all startups, "A" properly adjusted throttle plate, "A" good working IAC will race the engine up past its normal idling range and then, promptly drop to idle.

It should do this like clock work! No matter the conditions! Engine hot or cold!
This is and should be a constant "mental note" for the owner "everyday" and when mechanics are there to check upon these of type complaints. Did the mechanics ask about its everyday startups behavior?

Another tweaked in the mix is the AMM or I should say, "The Variable Makers" behind the AMM or any and all other vacuum leaks.
Both vacuum hoses and that "accordion hose" can let air in randomly.

If there is a loose or distorted clamping that can allow an air gap on the ends. Even having the tiniest split in one of those volutes which can pop open and back closed might explain things. As, Who knows when, how much or for how long they last?

All of this happens very slowly over time and goes basically unnoticed. That is, until the amount of air disrupts the mixture beyond the RANGE of instantaneous response of the IAC.

That air flow is really unmeasured.
The ECU has no clue about the "excess" except from the O2 sensor. So it adjusting away, going down the road, until you stop and tell the ECU want to idle now. Hopefully it gets told?

The 02 is still nice and hot. Exhaust flow drops, the 02 throws down a sweep of different voltages so now the ECU can be and is getting lost! UNLESS, the front in adjustments of the air and incoming information is dead on (normal operation) or it's "Catch it if you can time!"
Shudder and more shuddering begins with clacking of spark timing adjustments. All because, "wholly smokes", The RPM signal is totally unreadable into any program.

Bingo it, ECU Defaults into shut down mode to prevent engine damage!

Reset and restart, all is well!

Hopes this helps you! This helped me! I haven't posted in a while. The board has slowed down.
Good luck.
Phil

maybe the crank shaft sensor/wiring is/has gone bad, only finding a working spot once and awhile and other times not causing those problems.

gc

87 uses a Hall sensor in the distributor, no CPS until 89.
Dan

FWIW
I had a 87 740T, that the connector at the distributor had worn out, so i replaced the distributor and the wiring coming into it. Also replaced the main fuel pump harness from under the seat to the pump, later on, to correct sporadic acceleration
I'm thinking something fuel related, let us know how it turns out

oops

You don't mention if you checked/replaced the fuel pump relay or cleaned the contacts to the ignition fuse.

It sounds to me like it might be a dirty/failed idle air control valve. Remove and clean that.

When was the fuel filter last changed?
Did you check the fuel pump regulator?
Test the throttle position sensor on the throttle body.

Is your mechanic experienced with Volvos?

Thanks mrnabisco no not all looking at it is a volvo mechanic
Just one is. I need to find one in my area I wrote down your list to check. I did think of the idle control valve but I'm sure they will say just replace it. What is the fuel pump regulator? And throttle position sensor? What are their jobs? I also thought of the fuel pump relay but thought if it is not good it would not restart at all once it goes
Where are the contacts for the ignition fuse? Thanks for your help!

Please review all suggestions here for electromechanical problems that may cause your symptoms.

If you reside in an area of salt and snow, where cars are known to rust, the entire wiring harness at all connections, and connection to ground, are suspect. The corrosion at all wire harness interconnects can yield gremlin-like behaviors. Though the same holds true for a 1987 Volvo 240, or any 240, operating anywhere, globally.

Age and miles, and your locale, like salt and snow Minneapolis or Chicago, or dry Arizona, can have an effect.

At 28 years' of age, inside the fuel tank, the section of fuel line between the in-tank pre-pump and the fuel sending unit plate, secured to the top of the fuel tank, to which the low pressure fuel prime to the main fuel pump, and the low pressure fuel line returns, may have failed. If not already, all low pressure fuel line, on a 1987 Volvo 240, or any such aged Volvo auto, should be replaced with new fuel line meant for gasoline and ethanol mix. I think 12.7 mm inside diameter, yet forget the proper fuel line spec by name.

If not already replaced, doubtful any Volvo 240 to date has a solid fuel hose section between the in-tank pre-pump and the fuel sending unit plate.

A failing in-tank fuel pump, or if the sock filter on the in-tank pre-pump is clogged, may not be able to produce a plume of liquid gasoline high enough, to reach the fuel tank ceiling (if you will), and the metal fuel line section inside the fuel tank where the fuel line section may be. On the fuel tank exterior top, there is a low pressure fuel line that connects between the in-tank pre-pump output and the main fuel pump input (intake?).

As you turn, or corner, your 1987 Volvo 240, the fuel plume, if indeed that in-tank fuel hose section has deteriorated away, will miss the fuel tank ceiling so the main fuel pump remains primed. Also, that hose, at essence, become a liquid powder of very fine particulates or even a black sludge in the gasoline / ethanol mixture, that can clog the in-tank pre-pump sock filter and the main fuel pump filter.

If you create and register a proper brickboard.com account, and list your locale, it may be possible another brickboard.com member could help you in person. No, I'm not volunteering anyone. Just a suggestion.

I've also read there may be problems with the Volvo 240 ignition switch, certainly if you have a large and heavy key chain connected to it. It is best that you use a single key, or the lightest key chain arrangement possible as the ignition switch can suffer damage over time as well as the key cylinder lock.

As for Volvo-able mechanics in your area, see (copy and paste the URN):
- https://www.brickboard.com/SHOPS/
- http://www.volvomechanics.com/
- http://www.mechanicsfiles.com (Click and Clack Car Talk, I think)
- http://www.cartalk.com/mechanics-files

You will want to check with the BBB and other consumer protection services in your municipality, county, state, and at the federal level as useful. You can check the so-called opinion or review sites on the web, but bring a few salt grains with you as you do.

If your diagnostic and problem-solving finds you dealing with the fuel tank, our Art Benstein has detailed servicing the fuel sending unit, and replacing the main and pre pumps, and a host of adjacent systems that can help you and your mechanic. Please see:
- http://cleanflametrap.com/
- http://cleanflametrap.com/transferPump.htm (specifically)

Art B. I believe has a page here on main fuel pump issues not specific to Regina on 700. I recall a main fuel pump tear down page there, yet am not sure.

You may want to explore the Volvo 700-900-90 FAQ, click FAQ above, and explore issues on systems used on both 240 and those on 700 series, and perhaps early 900.

You should have Bosch LH-Jetronic 2.0, think. Using a test light or a multimeter, you can test continuity of the wire harness, verify whether the ECU(s) have fault codes, to help with your diagnosis.

Yet please review diagnostic and repair suggestions of the other brickboard member responses to your question. I'm guessing here as it is not listed in the set of possible causes here, yet. There may be a combination of faults causing your symptoms.

I think that does it.

Questions?

Back to cleaning out a Volvo 240, packin', and relocatin', to a locale without evil, mediocrity, and corruption.

Thanks,

Relocatin' MacDuffed.
--
The Volvo 164: The Mightiest of All Volvo Automobiles in Perpetuity

If it idles fine when the engine runs the IAC valve is OK, these are expensive.

Has the throttle body and IAC valve been cleaned recently?

Dan