From the life of a journeyman mechanic - when the engine no longer wants to deliver its power
A car of the higher displacement class came into the workshop; its owner complained that the car had not been running faster than 120 km/h on the highway for some time. Since the vehicle had only 40,000 km on the speedometer and an engine inspection had been carried out a few thousand kilometers earlier, the matter was still somewhat puzzling.
Nevertheless, the usual routine work that is usually carried out in the event of engine faults was started; the carburetor, the spark plugs and the ignition distributor contacts were checked or cleaned and replaced, and the ignition timing was also precisely adjusted. To complete the job, the mechanic replaced the capacitor on the breaker and checked the ignition coil.
After a satisfactory test run in the workshop, it was time to hit the highway. The journey seemed to be successful, as the car accelerated quite well on the way to the highway. But the joy was premature. At exactly 120 km/h, the engine began to stutter and stalled, so it was back to the workshop.
Now the mechanic became thoughtful and intervened to find the fault. In his opinion, it could only be the fuel supply. This time, the fuel pump was also removed, dismantled and overhauled. Before this, the delivery pressure was checked, which was at the lower limit. The subsequent test drive was again inconclusive: 120 km/h and not a kilometer faster.
The customer was then called and asked whether he had had to have something repaired at some point, perhaps on his last trip abroad. When he heard the word "abroad", he remembered that the fuel hose between the tank and pump had been replaced in Spain.
An inspection of this "Spanish" hose revealed that the rubber was not resistant to petrol and acids and that the inner cross-section had slowly shrunk due to swelling. At a speed of over 120 km/h, the flow rate was not sufficient to supply the carburetor with enough fuel, which caused it to stop. After the hose was replaced, the car ran at its old top speed again.
The lesson learned: ask the driver when and where someone last tampered with it. This often provides a clue.
This text comes from issue 22 of the 1959 edition of the magazine "Krafthand" .
