What to do when a carburetor cleaning doesn't help...
I bought a used Nissan Stanza with 65,000 miles which has two problems. First, when travelling on a highway with even a small grade, the car tends to lose power. I must downshift to as low as second gear and eventually pull onto the shoulder. After the car has rested and restarted, it runs satisfactorily for a few miles before the problem recurs. Second, the car is extremely difficult to start on cold mornings. However, after pumping the accelerator perhaps 40 to 50 times, I can get it started. A carburetor cleaning hasn't helped. Any ideas?
TOM: If you have to pump the pedal 40 to 50 times, you should see if you can get the original dealer invoice. This Stanza may have come with the Jane Fonda Leg Strengthening Package.
RAY: There are three other possibilities that come to mind. First, it could be a dirty fuel filter. The second possibility is a weak fuel pump. These are both hypotheses your mechanic can test for you.
TOM: The other possibility is that your fuel tank ventilation system is malfunctioning. This is something you can diagnose yourself. Next time you lose power, remove the gas cap. If you hear a "whooosh" when you remove the cap, stuff a rag in the gas tank opening. If the car runs fine with rag in there, it's probably the ventilation system. If none of these suggestions solve the problem, leave the rag in there and back up as close as you can to a lit gas grill. You won't have any more problems with this car after that!