Misbegotten Camry

1999 Toyota Camry four cylinder. No less than FIVE times, this vehicle has started in the morning, my wife has backed it out of the driveway and it has stalled and refused to start. Each time, I push it over to the curb. Come back in a few minutes or hours, and it starts fine.

I swapped the EFI main relay with another – identical relay. I replaced the fuel pump because the old one was either really quiet or intermittently dead. I bought a fuel pressure gauge and checked the pressure. Well within spec and held pressure for several hours – of course it was running then – of course. Check engine lights, nary a one.

Only odd thing. I gather from my reading that most cars turn on the fuel pump when the ignition is turned on. This one doesn’t turn it on until the starter is engaged. But it does turn it on and it stays on. The schematic is a bit ambiguous, but I think it is supposed to work that way.

I’m developing a deep and abiding hatred for this vehicle. There aren’t any convenient cliffs to drive it over, but there is a large lake that freezes solid in the Winter. I’m thinking, wait for February, drive it out behind an island and by April it should no longer be a problem.

What is it doing when it refuses to start? Turning over? Nothing?

I think the fuel pump does not come on until the fuel pressure in the line drops.

Have you by any chance had it scanned to see if it has any codes? Secondly, I have seen this on other cars not necessarily Camry; the crankshaft sensor or it’s wiring. This is a shot in the dark.

Turns over fires occasionally, but doesn’t catch and run. About what I’d expect if the fuel wasn’t under adequate pressure, but it could be something else of course. Unfortunately, the fuel pump is pretty much inaudible until the back seat is yanked out and removing the back seat is not my priority when the #&($&@ thing is stuck in the middle of the road.

Haven’t scanned. I can. But it entails an ancient laptop, An OBD to ASCII serial converter, an MSDOS program and a LOT of wires. I tend not to do it unless I have a solid trouble code. My assumption has been that anything that would set a useful code on the first start attempt in this situation would probably turn on the Check Engine light on the next. So, I’m assuming – No MIL, no scanable codes. Maybe I should go buy a cheap scanner. OBD2 doesn’t seem likely to go away any time soon.

Yeah, if I were designing a fuel delivery system, I’d probably use fuel line pressure to control the fuel pump, but apparently that doesn’t work well in Japan for some reason. Anyway, this Camry fuel pump doesn’t come on 'til the starter kicks over even when the fuel system pressure has just been relieved. There’s probably a good reason for that.

I still haven’t figured out what is wrong but for anyone pursuing a similar problem, you might want to look at the description of Toyota fuel delivery systems at http://www.autoshop101.com/forms/h42.pdf.

This particular vehicle has a returnless delivery system where the fuel pump runs constantly when the car is starting or running. Fuel pressure is regulated by a simple spring controlled mechanical regulator valve in the tank. I’m starting to suspect a that the problem is caused by inadvertent opening of a Circuit Opening Relay that is apparently there to make sure that if the ignition is on and the engine is not running – after an accident say – the fuel pump shuts off.

I don’t know. I’m getting an “ignition problem” vibe from this. Have you considered the coil, etc.?