By Glenn Goodspeed (June, 1992)
Ever have cold starting problems with your fuel injected B-20 or B-30 engine? Heh, heh. Thought so. If you've already checked the usual ignition and fuel supply items, and you know the cold start valve and thermal timer are working o.k. because you pulled the cold start valve and watched it spray a cloud of mist all over your engine (or into a jam jar if you were smart) when you cranked it over, then try replacing the seals, bushings, and o-rings on the injectors and injector holders.
Yes, I had this problem on a Volvo 164 engine not long ago. Man, I tried everything. I'm glad to know that everything else on the fuel injection and ignition systems was working just fine, but I still wish I had checked the seals first. At last, I reasoned it out. Oddly enough, Autobahn Volvo, our local dealer, had the parts on the shelf. I don't usually go to Autobahn for parts, but I had some time off from work and couldn't wait the week it takes to get stuff from Boston Volvo. I did have to swallow hard when they charged me $1.56 for each o-ring. O.K., they're special o-rings, not the same as the ones you get in the hardware store to fix your sink, but still, $1.56?
I actually changed out these parts when we first got the car about five years and 50,000 miles ago, so I was surprised when they turned out to be the culprits. At least now I know how long to expect them to last.
The symptoms of seal failure may be unique, so I'll note them here. The first, of course, is difficult starting in cold weather. The car starts fine and runs for a few seconds on the charge from the cold start valve. Then, because of the air let in by the worn-out seals, it dies or tries to. Usually, it runs on the second attempt at starting. Another symptom is the appearance of white deposits on one or more (but not all) spark plugs, indicating an overly lean gas/air mixture in those cylinders.
In a matter of months, especially in cold weather, the problem worsens so that it always takes two or three tries to get the engine running. After the engine warms up, it acts normal, probably because the gas/air mixture is not as critical when the engine is warm, and definitely because the seals and the metal of the engine expand in the heat, helping the seals do their job.
When injector seals are really bad, the engine idles and runs rough, due to the excessively lean mixture from air leakage around the injectors. This can cause serious damage to the engine, such as burned valves, broken or burned spark plugs, and burned injector tips.
When replacing seals, do a complete job, or the work you do may not be enough. You should replace the seals, which encircle the tips of the injectors, but also replace the bushings, which encircle the body of each injector. The bushing is important because it enables the fastening collar to apply the correct pressure on the tip seal.
In addition, you should replace the o-rings that seal the injector holders to the intake manifold. As I mentioned above, these are not plumbing o-rings, and should be purchased from a Volvo dealer. A very thin coating of silicone or "rubber" grease smeared on the seals, bushings, and o-rings will make them easier to seat properly.
While you're at it, it might be a good idea to replace the hoses that connect the injectors to the fuel distribution pipe. To remove the factory-installed hose clamp from an injector, you'll have to carefully cut into it with a hacksaw and then use a pair of pliers to peel it away from the hose. To remove the hose, cut it lengthwise with a utility knife.
When you replace these fuel hoses, don't scrimp on material. It's a lot of work to change them, and you only need a few feet of high-quality hose. I've used Gates and Dayco 5/16-inch fuel hose, and both are satisfactory, but I've never seen anything more durable than the Dayco hose. It's available at Kim's International, right across the street and a block down from Autobahn in Fort Worth.
December, 2005
Robert Jan Veraa adds this comment:
I used your report on the leaking injector on my 164 as I have been troubled with identical problems as in your report. In the end it turned out to be the paper seal of the cold start injector that leaked and not leaking main injector seals.
Anyway many thx for this very usefull tip and keep on Volvo-ing.
Krgrds
RJM Veraa