I own a 1982 BMW 320i with 80,000 miles. Since last summer the engine has been intermittently cutting out and losing power–sometimes for a splilt-second and sometimes longer. I’ve had the car to three mechanics. The intank fuel pump and fuel filter have been replaced, the oxygen sensor has been replaced, the electrical system checked an sparkplug wires replaced, etc. Nothing has helped and the car runs worse than ever; it now completely stalls sometimes. It’s then necessary to pump the accelerator furiously to get the engine restarted. Any suggestions?
Replace the fuse for the fuel pump even if it looks OK, this is a classic problem on old BMWs. A friend on mine bought a 320i very cheap because the owner couldn’t figure this problem out.
I’ll second Craig on checking the fuses. I think this car uses the old glass fuses with the stainless end caps. Over time the solder in the fuse melts a bit with heat and the connection can be lost. Check the fuses and make sure the end caps are tight on the glass.
Some years back I repaired a Ford Courier pickup that was suffering from something like this. The symptoms were exactly like yours and this vehicle as towed in to a shop 3 times for repair. Various things were replaced with the last repair being a diagnosis from outer space and costing the poor owner almost a grand. Two days later it quit again.
After hearing the symptoms described I got to looking at the fuses and sure enough the fuel pump fuse was coming apart.
A 25 cent fuse and total time including diagnosis was under 5 minutes.
This car uses CIS injection so there are a few other things it could be (sticking air meter plate, sticking plunger in the fuel distributor, etc.) but check the fuses first.
To “Craig”:
This looks absolutely too simple and too cheap to be right … and that’s why I’ll bet it is right! I went down to my garage where I store the ol’ beemer, opened the hood, took off the fusebox cover, and gave it a look. The fuse for the fuel pump didn’t look noticeably bad, but then, if the engine sometimes seems to run fine and at other times will barely run at all, what would it look like other than “okay” to the untrained eye? Anyway, I pulled it, as you suggested. There was a spare 8 amp fuse in the cover and so I put it in. I then took the car out for a spin … just a short one. It ran fine. I’ll admit that I’m leery about taking it out for a major drive as I fear that it will cut out entirely and I’ll end up being stuck, having to call AAA for a tow. But I will get over that soon enough and give the car a thorough test. I’m hopeful that this “too simple” solution will prove effective, but I can’t yet say that I’m optimistic; too many previous disappointments, I guess. Nevertheless, I’m very grateful for your advice, and I don’t know where I could have gone other than “Car Talk” to have gotten it. I think I may owe you a lot, and I hope my gratitude–if your advice proves to be on the mark–will be sufficient. Frankly, if you are right, I would like to buy you a great dinner at your favorite steakhouse … and I’m not kidding. Just let me know where and I’ll glady arrange to pick up the tab. Happy Easter! (You’ve certainly helped make mine so … I think.)
Mark Duchaine
Mapleton, Iowa
Ditto to you, my internet friend; your advice was corroborative and helpful. You are incorrect about the type of fuses used–not glass with stainless end caps. But your other comments were both informative and appreciative. And IF it should not be the fuse that’s causing the problem, you at least gave me two other possibilities as to what might be going on. Many thanks.
Don’t thank me yet, we don’t want to jinx it. (-; I hope it is that simple, those old fuses can be very flaky sometimes. Make sure the contacts in the fuse holder are clean with no corrosion, it doesn’t take much to heat up the fuse an cause it to fail. Let us know how it’s doing when you get a chance to take it for a longer ride. If I’m correct you can donate that steak dinner to a charity for me.
I like the old 320i, when they were new my girlfriend had one and I drove it quite a bit for a couple of years. Eventually she moved out and took the car, I missed the car.