Hi all! My 240 wagon worked fine earlier today and in fact just made two back to back trips to Oklahoma and did great. This afternoon I tried to start it and couldn't keep it running without pumping the gas hard and fast. It will fire right off but only run for a second or two unless I pump it. When I pump it, it runs extremely rough. It feels almost like it is out of gas but it's not(half tank). So I'm figuring either ignition or fuel feed problem. At times, I can get it to run at a pretty high RPM if I find the exact spot on the peddle, but not for long. I jumpered #4 and #6 fuse and can hear the pump running but still no fix. I thought "filter" but the high RPMs seem to rule that out. All fuses check out and there were no symptoms before. Recently (before long road trip) put new dist cap, rotor, spark wires, plugs, air filter, etc. Any ideas? This has been an awesome car till now and I don't like wanting to shoot it! Thanks!

Evan

Well, I changed the throttle switch this am. Slight improvement but as you can guess, no fix. I have a new AMM coming in tomorrow and will give that a shot. Man, I hope I didn't spend all that money and that's not it! Oh well, I would have just spent it on stupid things like bille! Anyway, I'll tell what happens after I install it. Thanks all!
Evan

Ok a quick update. Thanks for all the great responses too! I now have an almost full tank. I did check the fuel press regulator hose and it is dry. I also disconnected the AMM and can get it to run better. (I guess it's in "limp" mode cause it will run but still stumbles on quick acceleration) I did all the tests that are detailed in Haynes and the AMM checks good on all the tests. !!! Next I tested the throttle switch (TPS) and it has no continuity ever so I think it's bad. It also does not have the audible "click". I'll buy a new one Monday and try it. ??? I don't know though why if this is the problem the disconnected AMM helps especially since it checks out electrically. BTW Also checked the main 25 amp fuse and connections and the coil. It's good. Same with the air intake hoses to the throttle body.

Thanks again! I love this site!!!

Evan

In the limp home mode the engine should idle fine but it will not accelerate fast you have to be very gentle on the throttle to get it to move at all. This happened to me about a year ago, I drove home about 15 miles and with a manual trans it was a challenge. Get a used 007 AMM off ebay or a local bone yard. I believe you have a bad AMM. Dan

I tend to disagree with suspecting the tank pump because I've seen cars run seemingly well without it (though not good for the Main pump), and can't relate the tank pump to your "gas" pedal pumping.

As you know, all the pedal does is control the throttle, and thus the amount of air admitted to the engine. Maybe the pedal action is letting in extra air to allow an overrich mixture to burn erratically?

Have you pulled the vac hose on the Fuel Pressure Regulator to check for gas there (which shouldn't be the case)? A diaphragm leak would let gas get sucked straight into the manifold.

I would look at the plugs, after a starting "episode", and see if they look wet from excess fuel or rich-running?

If they look OK, then I'm the one who is all wet.

P.S. (1:00 PM) You might also try starting with the AMM unplugged. If it improves, the AMM is suspect. Sometimes just taking the AMM connector off and on cleans a contact or two.


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

Ok a quick update. I now have an almost full tank. I did check the fuel press regulator hose and it is dry. I also disconnected the AMM and can get it to run better. (I guess it's in "limp" mode cause it will run but still stumbles on quick acceleration) I did all the tests that are detailed in Haynes and the AMM checks good on all the tests. !!! Next I tested the throttle switch (TPS) and it has no continuity ever so I think it's bad. It also does not have the audible "click". I'll buy a new one Monday and try it. ??? I don't know though why if this is the problem the disconnected AMM helps especially since it checks out electrically. BTW Also checked the main 25 amp fuse and connections and the coil. It's good. Same with the air intake hoses to the throttle body.

Thanks again! I love this site!!!

Evan

1) I also disconnected the AMM and can get it to run better.
That is THE definitive test for a failing AMM.

2) I did all the tests that are detailed in Haynes and the AMM checks good on all the tests. !!!
The consensus among Brickboard experts is that these meter tests seldom prove anything, and are not to be relied on.

3) Next I tested the throttle switch (TPS) and it has no continuity ever so I think it's bad. It also does not have the audible "click". I'll buy a new one Monday and try it. ???
Good idea, if you checked between center terminal to the Idle terminal.

4) I don't know though why if this is the problem the disconnected AMM helps especially since it checks out electrically.
The TPS is probably a secondary problem. IMO, the unplugged AMM is more significant, and the meter tests are questionable at best
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

I tend to agree with this, or at least the direction it's going.

Also inspect the dist cap and rotor for corrosion, carbon, moisture, or damage. Clean the contacts for now with a thin screwdriver or pocketknife. Replace if the cap is at all cruddy.

Inspect the coil wire. Make sure it hasn't gotten grooved rubbing against something like the power steering pump. That would cause it to lose spark.

The fuel pump relay is always suspect, as is the 25A fuseholder behind the battery.

The AMM connections are also a good place to look. While you're at it, look for holes in the intake air hose from AMM to throttle. Could be getting lots of unregulated air leaking.

If none of this improves it, try the AMM unplugged trick. It'll stall at full throttle but should recover after a restart. Otherwise may run just fine. Try another AMM after that.

Check the timing- make sure also that the timing belt is tight and has not jumped a tooth or three. A sanity check would be to pull the timing cover back, pull the dist cap, and rotate engine till the crank pulley is at TDC (0). Is the cam sprocket at it's mark? If 180° out, rotate engine one full turn. If timing mark on cam is good, go on to distributor- the rotor ought to point at a tick mark on the top of the dist body. There's another timing mark on the pulley for the intermidiate shaft that drives the dist- it's harder to see though.
Good luck!
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Rob Bareiss, New London CT ::: Roterande Fläkt Och Drivremmar!

All good stuff Rob, but I believe that at 0° TDC, the rotor should be a good 1/4" past the tic mark, assuming a nominal 10° initial timing advance.

That's been my experience anyway, on the cars where we can still set the ignition timing.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Until you get other suggestions, try putting in more gas. Going over the back roads may have loosened the intake tube in the in-take pump so it isn't sucking in fuel well below 1/2 tank.
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1980 245 Canadian B21A with SU carb and M46 trans

following on trev29's advice - the in-tank pump rides in a little frame that mounts on the gas intake tube inside the tank. the rubber hose that connects the pump to the tube is flexible and thin - it rots after twenty years or so. if your problem does go away when you fill up, then this hoose probably needs replacing. it's worth replacing the in-tank pump and the sleeve filter on the pump at the same time.
if you end up doing this, check carefully the in-tank pump ground wire connection. it's a spade connector on top of the round plate that the intake and return tubes mount to.
even though it's on top of the tank, it's still outside the car body and subject to corrosion from water and salt.