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Re: hard starts: Fuel Pump or ? Posted by Ari [Email] ![]() ![]() In Reply to: hard starts: Fuel Pump or ?, bg, Thu, 9 Aug 2001 11:14:32 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Two things that lead to hard starting - how fast the engine cranks, and fuel pressure.
If the engine seems like it's cranking slowly, then think electrical - is the starter getting enough juice? This can be battery connections, battery cables, starter solenoid. All of those effect how much current gets to the starter motor, which is how fast it turns. Higher temperatures mean more resistance, and that means less current and a slower starter motor.
If the cranking is OK, think fuel pressure. There's a lot that goes into fuel pressure. Of course, there's the fuel pump, but there's also the fuel pressure regulator, and the accumulator (not the right word). The accumulator helps maintain fuel pressure so that hot restarts are quicker. If that leaks down too fast, it'll take longer to build up fuel pressure and start the car.
As to the hard starting and temperature - is the starting hard first thing in the morning, and then again througout the day, or is it only when both the car and the temperature are hot? Basically, if the car has been turned off for only a couple of hours or less and it's hard to start, I'd suspect the fuel accumulator is leaking pressure down. If it's just plain hard to start all the time, it could be the fuel pump or FPR.
This is pretty easy to check with the right equipment. I recommend a shop do this test - basically, you put a fuel pressure gauge in the line to see what your fuel pressure is and how fast it gets to pressure. You then check fuel delivery - open a line, and see how long it takes to pump out 100 ml of fuel. With pressurized fuel spraying around, you can see why it's a good idea to have someone experienced do it. But that will help pinpoint the problem. It's cheaper to pay for a few tests than to just start replacing parts that might be perfectly fine.
good luck!
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