I don't actually own a Lexus myself, however, I'm trying to figure out why is it that my friend's 2004 RX330 refused to start. It's to return a favor.
Beginning with the simplest procedure, engine cranks over, and there is spark, as I grounded the coil + spark plug and asked him to crank... so crank and cam angle sensor should be fine. All spark plugs are completely dry without a single petrol fume. So obviously we're missing fuel here.
I didn't hear the fuel pump priming the system when turning the ignition key to the "ON" position. Cracking open the banjo bolt on the fuel rail released the rail pressure, but further cranking does not introduce further fuel spill. I don't even feel any vibration when I put my hand on the fuel tank, as my friend turn it to "ON"
So I'm wondering if my diagnostic could be wrong.. I know it's a Lexus, but I think the fuel pump priming should still be audible? Unless the sound insulation is that good that it played tricks on my ears??
Also, where/which one is the fuel pump relay in this model? It's unlikely for a relay to fail, especially at 4 yrs old, but who knows, they tend to run very hot.
I would love to hook up 12V to the fuel pump, but doing so requires dropping the fuel tank on the ground, and it's 3/4 full.
Any idea how much a fuel pump would cost for it, if it is indeed the culprit?
I forgot to check if the relay actually clicks, it was getting dark and temperature drops too fast.. Especially when the stomach's empty...lol.
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Just a quickie...
Got access to fuel pump without dropping down the fuel tank. Removal of rear left passenger seat was necessary, along with moving around the floor carpeting to gain access to the fuel pump's access cover. Power connector on the pump's lid are the 2 at the small end, left one is ground, right one is +12 . Tested, fuel pump works just fine.
Went back to the relay box, and replaced the EFI MAIN relay with the one out of my old car (similar pattern), crank engine and it runs.
So apparently, while the contacts that channel ignition signal were fine (it clicks), the contacts that channel 12V straight from battery were toast.
5V terminals are the silver spades, 12V are the copper ones.
So now the RX330 is running with the horn relay out of my car. The very same relay also runs the fuel pump in my car.
Oh, and my boss told me the fuel pump for it will be in the $250-$350 range.
Expect a relay to be $20-ish max.
A decent mechanic should be able to troubleshoot this matter within the 1 hour minimum, plus 30 minutes or so to access to the pump and tidy things up.
Generally, a fuel pump should last for the life of the car, unless if it ran dry too often, which usually happen when the in-tank filter got clogged, or else the car was frequently run to the last drop of fuel.
A relay failure in a 4 years old car is not as common as corroded battery terminals would be, but the possibility is still there.
I wish toyota could have put the relay elsewhere, where it get proper cooling, as these small relays do run very hot.
