Help.

I recently bought a 1973 volvo 144. It runs very well at high speeds, and most of the time at low speeds.

But: 1. It can take a long time to start, turning over until finally it catches. But once it has started, then it starts pretty much right away if you turn it off and then start it again.
2. After I turn off the ignition it continues to sputter for a few seconds. I think this is called 'dieselling'?
3. If the choke is in, and I put on the brakes to come to a stop at a light, or if I am just sitting there idling, the idle is very rough, and often it will stall. I just had it on my first long trip, travelling at 70mph for six hours, and after that trip the problem was worse. While at my destination I had to pull the choke out all the way when coming to a red light to keep it from stalling.
4. And at one point it would hardly run at all, even with the choke fully out. But that may be because I was just leaving the choke out while in the town that morning, because I was tired of pulling it out when I came to a stop sign. Did I possibly flood it?
4. I let the gas tank get very low on that trip. Pehaps there is gunk in it?

Any ideas to guide my mechanics?

Greg MacIsaac
gregory_macisaac@carleton.ca

The B18 in my 122 wagon used to diesel terribly after shut off. The carb is a Weber DGEV; it's no SU, but quite acceptable for my needs. Problem turned out to be weak fuel mixture with timing too far advanced. I adjusted mixture using a Colortune, and set the timing to point whewre there was no pinging, aroung 15 degrees ATDC in my case.

No more dieseling, 27 MPG, excellent acceleration/ performance throughout RPM range, had my baby going 90 this afternoon for a while, before I decided to quit driving like an idiot, it was fun while it lasted.

Welcome to your "new" car, it will bring you much fun! So, is it carburated? If it is, and I think it is because it has a choke, I think you should definitely check out the fuel filter, not because of the symptoms, but just because you ran the tank low, and also the little plastic fuel filter in the fuel pump. This only applies to the carburated motor though. So, we'll see. As far as your brake booster, you will be able to tell if it is leaking if you push on the pedal hard and if it progressively sinks towards the floor, I'd say you have a leaking brake booster.(that is while the engine is running) Hope some of this helps!
Later,
Kyle - KLR142 in Portland OR

Double check for intake manifold gasket leaks. The retaining nuts tend to loosen up from the engine vibrations. You can use carb spray around the gaskets to check the gaskets. If the engine revs up when you spray you've probably got a leak. Be aware that worn throttle shafts can also suck in some of the spray & fool you, so try to direct small shots of fluid at just a portion of the gaskets. Intake leaks suck! Good hunting.



Mike M.

Possibly your brake booster is leaking air into the intake manifold. Does it idle OK when you have had your foot off the brake for a while?

An easy way to check the brake booster is to squeeze off the vacuum line at the manifold with a vise grips. If it runs better you've found the vac. leak.



Mike M.

Thanks for your quick response.

I will check out what you have suggested. The brakes are also not the best. After I start it, I have to press on the brakes for about 10 seconds before the pedel will depress well, otherwise I have hardly any brakes at all. And even after that, the brakes are not super responsive, like in a new car, which I would expect, but not to this degree. They will stop the car fine, but I have to press very hard.

Greg