Is this a fuel problem?



I have a 1995 Lexus ES300 with 180k miles. Occasionally, when I start the car, the engine turns over and begins to idle, but very quickly comes back down and will either stall completely or waver back and forth and then, may or may not stall. This problem used to happen very infrequently(once every 3 months or so), but has been happening more and more often(1-2 times a week).

I use the following solution: After the car stalls, I turn it on again, with the accelerator all the way down, so the engine revs up to 5 or 6000 rpms and when I let the engine come back down, it is almost always able to idle like normal. I’m not a car expert, but it seems like maybe the fuel lines are clogged and when I rev it, it breaks up the clog??

Thanks for the help!


Not likely. More likely some of the fuel in your lines is draining back into your fuel tank. Then, after you’ve started it once and it’s drained what’s in the fuel distribution manifold, it dies. By that time the pump has run long enough to fill the lines and everything begins acting normally.

For the line to drain two thing sneed to be true: (1) you need to have a faulty check valve at the pump end, and (2) you need to have a leaky injector allowing air to get into the lines…otherwise it’ll act like a drinking straw does when you plug the end and lift it. Unless air can get into the line to displace it, gas won’t be allowed to drain out. Call i the “pipette” theory if you’d like.

Try this: put the key to “on” for three or four seconds before starting it every time and see if the problem goes away. If my theory is correct, that’ll allow the fuel pump to fill and pressurize the line and it should run normally.