Edmunds Answers



  • zaken1 03/05/10 4:39 pm PST

    Please try the following starting technique: Turn the ignition key to the position where the warning lights on the dashboard come on, and wait with the key in that position for a full ten seconds. Then turn the key the rest of the way to start the engine.

    The reason this works (and is so necessary) is that modern cars are being calibrated with leaner and leaner air/fuel mixtures; to meet emission control regulations. At the same time, all fuel sold in the US now has oxygenating additives in it (typically ethanol); again to meet emission regulations. Both of these things lean out the mixture during starting.

    It takes about ten seconds after the key is turned on for the electric fuel pump to build up normal fuel pressure at the fuel injectors. If you try to start the motor before there is full fuel pressure; the mixture will be even leaner than it was intended to be; and this causes difficulty in starting.

    Messing with the fuel pressure regulator will just reduce your present excellent fuel economy; but since it still takes the same amount of time to build up full fuel pressure; changing the regulator setting to a greater than normal pressure will not improve the starting performance when you don't wait for the pressure to build up.

  • alaskanj 03/05/10 9:16 pm PST

    So is there a fix or solution to the problem. Or do you just wait 10seconds everytime its a hard start? I see this answer all over in here, not sayin it dont work, but seems like there should be a solution... Or am I missing out or overlookin something here???

  • zaken1 03/05/10 9:31 pm PST

    This problem only began when fuel pumps were removed from the engine and put in the gas tank. Moving the pump created a 5 foot long fuel line between the pump and the engine. That line drains back when the engine is shut off; which is what creates the built in delay when the pump starts.

    I have received more "best answer" points for that solution than for probably any of the other 1,600+ answers I have posted. You won't see that answer anywhere else; because I seem to be the only person who has figured it out. But this solution only works for those who don't insist that cars are inherently perfect; and as such, modifying the driver's behavior should never be necessary.

  • alaskanj 03/05/10 10:01 pm PST

    If this were so then we should see this problem in all vehicles that have the pump in the tank. Unless the real problem is the fuel pump is getting fatigued/ wore out or there is a restriction in the fuel system such as the fuel filter or the little strainer on the pump inlet. If there is said debris in the fuel filter, it had to flow through the pump to get there so the pump could suffer damage as well. So a pressure test is not the only test to be perfomed, while doing the psi test I would do a fuel pump volume test too and minimun pump flow should be 1 pint in 15-20 seconds..

  • zaken1 03/05/10 11:20 pm PST

    This problem is not found on all cars which have the pump in the tank, because all vehicles do not have the same fuel mixture. Depending on the quality of their break in, and the type of oil that they use; some engines run substantially richer than others. (I'm not talking about vehicles with compression, fuel or ignition problems here. These starting complaints come from vehicles which, when tested, meet all the manufacturer's specifications.) Only the leanest running vehicles (which incidentally are the ones that have the best compression) tend to be so lean during starting that there is not enough extra fuel available to start easily when the key is turned too quickly and the fuel pressure is below normal.

    You might appreciate this more if you read about the fuel mixtures which were normally used in the 1950s and early 1960s, before emission control laws came into effect. In those days, many vehicles idled with air fuel ratios of 11:1 or 12:1. Those motors often put out 1,000 parts per million of unburned hydrocarbons; but started immediately when the key was turned, and idled as smooth as glass. When emission control laws were implemented, and air/fuel ratios were leaned out to 14:1 or higher, the unburned hydrocarbon levels dropped by 90% or more; but then people began complaining that their cars would not idle as smoothly as they used to, and that they would often stall after they were first started. So emission controlled fuel calibrations created a bunch of driveability problems. It took many subsequent years of experience, along with much experimentation and research on ignition systems, camshaft profiles, fuel delivery systems, and combustion chamber design, before those problems were largely corrected; but some of them have still never really been fixed. And during the 1990s, as in tank fuel pumps became standard, while emission laws became even stricter, and reformulated and oxygenated fuels became increasingly common; more and more people began experiencing starting problems.

    Perhaps you can find a different way to fix those cars which now run properly when warm, and do not show any problems in diagnostic tests; but are hard starting at the times when the fuel pressure has not built up to normal. If you ever do; I'll be the first to congratulate you. But until that day; I'm going to continue to tell people who ask about the only answer that yet has been proven to work.


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