Hello All:

1967 122S wagon. I have owned it for less than three weeks. It has 71,000 original miles and is overall in great shape, prior owner was a Volvo tech in Huntsville, AL. Recently cleaned carbs, new fuel lines, new fuel pump. Why am I focusing on the fuel system? Read on.

Last night, just after sundown (naturally) I had just made a clean clutchless shift into fourth gear and suddenly the engine cut out. No sputter, no loss of drive, simply silence. I quickly checked the fuel gauge and saw that I had nearly ½ tank. I pulled over, popped the hood, checked all of the hoses, belts and wires to make sure everyone was happy, and tried to start it again. It did turn over without trouble, and would sporadically start and idle nicely, but after about a minute it would just die again. A police officer helped me to call AAA, and I was able to get it started several more times and get further down the road, around 1/10 mile each time before the engine would just die, and then not start for a while. All lights and other electrical worked, as well as the starter motor. I did not have the choke open, and obviously I am not flooding it, so I concluded that there must be a fuel-mixture-flow problem. AAA towed me the last couple of miles home. A very nice guy, and he treated the car with such incredible care it was actually kind of touching. He was really in awe of her. Of course, I had just washed and waxed her so she was looking very pretty indeed.

Check my math here. Logic dictates to start by checking the fuel filter at the top of the fuel pump, correct? I assume that if the fuel pump failed outright I would not be able to get the car to re-start at all. The question is, why does the engine run for a minute or two and THEN die? I was wondering if there might be an air-flow problem. Theoretically, what would the symptoms be if there was not enough air getting into the final fuel mixture? Leaning on the throttle hard or opening the choke did not make the problem go away.

I am mechanically inclined but not mechanically knowledgable. I have put together a couple of Formula Ford motors so I know the ins and outs but diagnosing problems is still a fairly new field for me, and the black art of carbs, well, I am not a great artist, yet. I have about a week to get this thing running again. Can anyone help me?

Cheers,

Jeff Pucillo

Jeff:

When I first read your post I, too, thought of a rusty fuel tank. Sounds like that is ruled out if it was recently cleaned. Just a couple of other things to consider:

Was this car used regularly before you bought it? If not, the gas in the tank could be bad and could have fouled the plugs. Old gas turns to varnish in the tank and plugs don't like to burn it.

If the entire tank was sealed on the inside you could have a problem with the sealant plugging the pickup tube. I have heard of people sealing them shut. In your case it might be partially occluded and a small bit of debris is finishing the job.

Please post again when you find the answer.

Hi.

You can follow the diagnoses algoritmh on http://www.recarbco.com/technical/newtrouble.html, it works for me on a similar situation.

Also, I suggest to put two fuel filters: one before the pump (universal type) and other (usually a bit smaller - I use a cheap Volkswagen beetle gas filter) after it. Both filters transparent (you can see how dirty they are).

The first filter intercept any garbage coming from the tank before it blocks or damages the pump internal valves, the second prevent small particles (from the pump, it also degrade with time) to get into the carburetor, preventing sticking needles valves and consequently, undesirable fires in the engine bay.

Also, a magnet on the line help help to catch the small metalic particles (btw: I use another big magnet on the oil filter and other on the drain bolt on the carter - that two sourced from IPD - it really works on our old irons).

Small particles comes from rust tanks (car or pump station or dirty storage bin - you not know), internal rust pipes, and also from bits of the seal material used for rebuilld de the tank.

Also, I suggest to clean the carb faucets with some carb sprayer (not recomendable if you have Zenith Stromberg carbs due the spray attacks the diapraghm, sometimes it helps.

Take it with a bit of serendipity. Happy debugging!.

Joaquin
Rojo 121 Amazon
Lima Peru

There is one other possible problem not mentioned in previous posts that
might give similar symptoms. The fiber timing gear will sometimes fail over
a period of time, especially when coming loose from the knurled steel hub.
In my experience it happens like this:
You wind it up pretty hard and when you get to about 4500 rpm or so it is like
you suddenly turned off the switch. You step on the clutch and roll to a stop
and find it is idling perfectly. This happens several more times at
successively lower speeds, and then it just quits, won't start, fire or
anything. Usually you'll hear a significant knocking from the timing cover
(although it is hard to tell exactly where it is coming from) before it
finally completely lets go. When it is starting to fail you can tell because
with a timing light, at steady or slightly varying speed the timing will vary
more than you would expect. When it does let go completely you can tell because
the distributor doesn't turn when you crank the engine.
--
George Downs, Bartlesville, Oklahoma, Central US

Hello George:

First off, this happened on my way back from Home Depot, where I successfully procured my rear seat belt bolts. Thanks again for the tremendous advice.

What you are describing above simply does not match the experience I had last night. I have many tests to run tonight before I get desperate.

Cheers,

Jeff Pucillo

I've had a timing gear come apart like that before (the fiber portion was completely loose from the steel center and fell out when I removed the timing cover). In my case it still ran fine - never missed a beat on the remaining 30 miles home. At idle it would make a very bad deep knocking sound, just like a rod knock only at idle, fading as the rpms rose.

Next time the engine dies just quickly pop off the rear carb's float bowl cover and see if there is fuel in the bowl. If there is it might tend to focus attention elsewhere. (next best suspect is the ignition)
--
I'm JohnMc, and I approved this message.

I'm going with the fuel delivery problem... clogged line, bad fuel pump, out of gas, or water in the gas.

122 wagons ain't prone to water getting in the gas, so I'd rule that one out for now. Get a piece of... perhaps 5/16" or so copper pipe, and plug it into the piece of fuel line that goes into the fuel pump, and and blow in it... have an assistant listen for bubbles in the tank.

If you can blow through it but no bubbles, the line is clear, but you're out of gas. If you can blow through it, and hear bubbles, you're OK.

Make sure you can blow through the line between the carbs and the pump... with said line disconnected from the pump.

Replace or install any and all in-line filters.

After you've determined that all the lines are clear, replace the fuel pump and you'll be happily motoring along your way. My money is on the fuel pump being the problem.

I always keep a spare pump with me... only takes about 5 minutes to replace roadside... has saved me more times than I can count.

Soounds like a wonderful car... 71k original... geez, I'm envious!

-Matt
--
-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC

I had a similar problem once with a '54 Chevy pickup. The fuel pickup tube in the tank did not have a strainer over the end - just an open tube. When the fuel level got low enough a splinter of wood (!) floating in the tank would enter and clog the pickup tube. It would then fall back out after awhile, then the engine would start and run ok until the next time. I found it because I could not blow back through the fuel line to the tank and hear any bubbles.

A clogging fuel filter usually causes your top speed to gradually decrease until you can't run above 60 - 70 mph, then you notice it.

Take the fuel line off the carb and put it in a can or jar. Crank over a few times while you look for a nice volume of gas coming out. If you aren't getting nice squrts of fuel gushing out then there is a problem.

The symptoms sounds pretty much like bad fuel flow. When cranking if a little gas is still flowing it can fill the fuel bowls of the carb, and when it starts the engine will run fine until it sucks them dry again. I had this issue for about 6 months after reviving my PV from a 15+ year slumber. I just kept swapping those filters, eventually got most of it out of the system. Probably would have been a better idea to just clean the tank properly to begin with...

Other more subtle problems with fuel flow - leaking valves in the fuel pump, a non vented gas cap, tiny holes in the line between the tank and pump allowing air in.

--
I'm JohnMc, and I approved this message.

Hello John:

Thanks for explanation of what might be happening internally. I now know more about the carbs than I used to and it makes perfect sense based on what I was experiencing. I will try it and report back tomorrow.

Cheers,

Jeff Pucillo

Jeff: My thoughts and experience on your problem.......

This happened to my 444 after 6 years of inactivity. Small rust particles were dislodged from the fuel tank. I installed a second inline filter before the fuel pump and it clogged within a few weeks. The symptom was exactly as you've described - loss of power, engine stalls, wait a minute, then engine starts. After doing this a few times, I realized that if I kept the speed down (I live in the country), then I was able to limp home without a repeat of the symptom. Needless to say, when I removed the extra filter, it was clogged.

I'd at least replace the external fuel filter that might clog when a higher volume of fuel is expected. The earlier AC fuel pumps had a sight glass that would trap contaminents from the fuel tank. I now keep an eye on the glass and clean it out when I get sediment in the fuel pump. I drove 1,000 kilometers on the weekend without a problem! Good luck.
--
Cam a.k.a. CVOLVO.COM

Hello Cam:

Thanks for the kind words, and so quickly.

I have a Clymer's manual here and I can see that there is a filter that lives in the top of the fuel pump, accessible by removing a screw in the top. On the line prior to this fuel pump is a silver cylinder about 2" in diameter and the fuel hose passes through the center of the cylinder, concentrically. Is this an additional fuel filter like you are describing? If so, how do I open and check it? What safety procedures do I need to follow in order to examine these parts without blowing the car up?

Cheers,

Jeff Pucillo

The quick and dirty thing to do is take the filter out and blow back
through it. This should get it clean enough that you can drive it home,
when you put it back on.

(Don't have it pointed at yourself when you blow through it! Also avoid
fire or flame or other sources of ignition.)
--
George Downs, Bartlesville, Oklahoma, Central US

You don't open the cylinder it is a throw-away. A replacement "universal" filter from NAPA or the like will work fine.
Once the old one is out, inverting it (input side down) will quickly shoe any gunk in the line!

Mike!

Yep, rust gets sucked into the filter and clogs it, then when the pressure is off, it backflows just enough to release the rust from filter temporarily until you start again.

I have more limp home modes than (at which you can) shake a stick. My favorite is running on only the cold start injector.
--
'74 145e T-5 'Orange Alert'

Hello Michael:

The gas tank was recently cut open, sandblasted down to the metal, rewelded and sealed with some special material that I wrote down at home. I doubt there is rust coming from the tank but certainly anything is possible. Any idea how I get into the tank to check for the presence of debris?

Cheers,

Jeff Pucillo

You'll see the debris in your fuel filter and your carbs!
You can look into the fuel gauge sender port on top of the tank (in the
bottom of your trunk under the mat) but the baffles in there keep you from
seeing much.
--
George Downs, Bartlesville, Oklahoma, Central US

I think with fuel delivery problems it WOULD sputter.

I'd look at the ignition system. Loose wires? Broken wires? Something shorting to ground? Does it always happen when you shift into fourth?

Clutchless shift? Be careful for your synchros.

Hello Joris:

There is the slightest sputter, but there is no misfiring or coughing. I checked the wires carefully and everything seemed happy. If I understand things correctly, the only wire issue that would make sense is the wire between the coil and the distributor, correct? Any of the four wires to the individual plugs would give me a misfire correct?

I know enough about the innards of a gearbox to know what a synchro is and what it does. Can you explain your concern with respect to shifting without the clutch?

Cheers,

Jeff Pucillo

If it simply stopped dead, you'd be looking at the primary ignition circuit. If only one cylinder was not firing, your engine would be running although you'd notice the loss of power. Most people seem to suspect a rusty fuel tank though.

Use of clutch: not that I'm an expert on this, but my reasoning is as follows:

The synchros are used to match the rotation speeds of the transmission input and output shafts before engaging a gear. The output shaft always turns proportional to road speed. The input shaft (ignoring the clutch) always turns at engine speed. Both the rolling car and the running engine have quite some inertia.

If you use the clutch, the only mass the synchro has to slow down is the freely rotating input shaft.

If you don't use the clutch, the masses to be synchronized are much greater. If you force it in gear, the synchro will be strained a lot. If you lightly push it until it slips in gear (when the motor revved down enough to match the revs), you have friction until the gear engages.

Maybe it does not make a difference in reality, but the clutch is made to cope with a lot of friction, the synchronizers are not. I think I know which one I'd rather change :)

Same story for the overdrive if you have one. Some people use the clutch when engaging OD, others don't. But if you want to put the least strain on your internal OD clutch, use the clutch.

Jeff,
The only thing I can add to this discussion is that I once had a pick-up tube inside my tank that had a corrosion perforation a couple of inches from its bottom end. When the fuel dropped to that level the pump sucked air. Not likely to be your problem if you have recently driven the car till the tank was near empty, and certainly not with the work you had done to the tank, but when all else fails . . . . . . Blowing through the line should tell you -- no bubbles, just air, while there is still fuel in the tank would mean pick-up tube failure of some sort.
Good luck,
Bob S.

Hello Joris:

Great explanation of all things, thanks for taking the time.

Cheers,

Jeff Pucillo