Out of nowhere my engine cranks but does not start?

BENJAMINTHERERRIBLE

MEMBER
2002 TOYOTA AVALON
3.0L
V6
2WD
AUTOMATIC
260,000 MILES

Seemingly out of nowhere my car cranks but doesn’t turn over. Plenty of battery (also tried with jumper assistance to be sure). When I turn the key, I don’t hear the pump priming, so almost certain has to be fuel delivery. Where do I start with troubleshooting? I’ve checked the fuses and relays under the hood, they are all in working order. Are there any related to this circuit in the cabin? I don’t have a diagram for the PCs fuses/relays. Thank you as always!

7 Replies

KEN L

MASTER CERTIFIED MECHANIC
43,067 POSTS

How does it sound when cranking over, does it sound like there is no compression? If so, the timing belt has let go, which is common on these vehicles. To be sure you can upload a short video of the engine cranking and I can tell for sure. Here is a diagram for the timing belt so you can see what I am talking about. Also, this guide can help as well:

https://www.2carpros.com/articles/car-not-running-advanced

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

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Thursday, October 12th, 2023 AT 11:12 AM

BENJAMINTHERERRIBLE

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Thanks for your response. I’ll get a video uploaded in a little while.
If it makes any difference, the cranking sounds exactly the same as it always has.

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Friday, October 13th, 2023 AT 5:10 AM

KEN L

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Okay, if you turn the key on without cranking the engine over can you hear the fuel pump run inside the gas tank for about 5 seconds? Will the engine run on starting fluid?

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Friday, October 13th, 2023 AT 8:48 AM

BENJAMINTHERERRIBLE

MEMBER
46 POSTS

Like do I hear the fuel pump priming when I turn the key? No, I don’t. I have to suspect that it has to be related to fuel delivery because all the other elements to start are there (didn’t check the spark plugs, but I did inspect them just a couple months ago and they looked perfectly fine).
I also understand that there are a number of different relays that the fuel pump circuit runs though. Are any of them in the passenger compartment? I want to check those before I assume that it’s the fuel pump itself.

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Friday, October 13th, 2023 AT 10:43 PM

KEN L

MASTER CERTIFIED MECHANIC
43,067 POSTS

They call the fuel pump relay a "circuit open" relay. Here are the engine and fuel pump wiring diagrams for you to see how the system works. This guide can show you how to test the relay if you need it:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Here is the location of the circuit open relay as well. Check out the images (below). Please let us know what happens.

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