Help! Engine cranks, but no start!

My 4Runner last week was working just fine, able to crank and start up with not a problem. As of recently, it has become parked because it doesn't want to fire right up. It cranks, but fuel doesn't seem to be going through it. I have replaced from the fuel pump, filter, 3 relays that pertained to it, and still nothing! The Blue/orange wire that supplies power to the pump doesn't read anything, and checked all the wiring and everything seems fine. Can anyone help me out, this has become really fustrating.

 

Does it have fuel? Don't trust the gauge
Does it have air? Plugged air filter or ripped intake hose
Does it have spark? Pull a spark plug wire and put a small bolt in it and place it near exhaust manifold to check for an arc when cranking. Beware of exposed fingers because it will zap you

 

Everyone is fine and dandy. It gots lots of air, good intake hose, air filter clean and new as can be
All spark plugs are good and spark fine. I did get a small shock out of it!
And I got about a nearly full tank (Damn!) but when I hooked it up to a 12 volt table top tester on the ground and power leads of the pump itself, I can hear it whir, so the pump isn't out.

 

I sprayed quite a bit of starter fluid in the throttle, and it turned over just fine, but died afterwards.
That I did notice, which there is literally no pressure in the fuel rail, and taking off the fuel line before the fuel filter, I cranked over and nothing spurted out.
That I know for sure, the pump is not getting any sort of power from the actual power line that comes from underneath the dash of the driver's side, from the relay, and to the pump itself; Although, just to make sure the wire wasn't faulty, I jumped it from the diagnostic box on the top intake manifold, to the positive terminal of the battery, and lo-and-behold; Power to the pump and it fires right up! Ran perfectly normal. So it makes me wonder if the wire itself is shorted somewhere in the cab or engine bay or maybe the wire is out of place and isn't getting anything in first place?

 

We're having the same problem. Did you get it fixed?

 

I have a 2020 TRD OR that cranks but won’t turnover. I just got a new key made and I’m wondering if it’s been programmed correctly.

 

I have a 2011 Toyota 4Runner SR5. When COVID started, it sat in the garage for almost 2 months and when we went to start it, the battery was completely dead. We replaced the battery. A few months later, we began having the issue described in this post--it would crank, but it wouldn't start. It would eventually start, but it could take up to 5m and multiple attempts. A few months later, the battery was dead again--and so we replaced it (AutoZone basically traded us outright for it). This combination of events has taken place for the past 2 years. Our local Toyota was unable to duplicate the problem each time we took it to them to look at, and because the batteries kept having to get replaced, they were unable to locate any "error codes", so we had to wait this out. The cranking but not starting problem isn't something that we can re-create; it might happen once every 3 months, or once every 3 days, or even once every 3 hours. It varies--no consistency to it. We were advised to take a video when it happens, which we did (we have several videos) and showed it to our local Toyota. The cranking and not starting problem has been occurring more frequently, and fortunately the battery is still working so the error codes could be read by Toyota. They used a "flow chart" to troubleshoot and said the issue is either a faulty ECU that controls the fuel pump or a faulty fuel pump based upon the error codes. On 10/13/2022, they replaced the ECU, but within a few days, the problem happened again, so they said we need to replace the fuel pump, which was done on 10/26/2022. Two nights ago, the problem happened yet again. Now, we have paid over $2,000 for an ECU and fuel pump and we still have the problem!! I called Toyota yesterday and told them that it is happening again, and they asked where we get our gas because if we don't get it from Shell, that might be the problem. We do get it from Shell, but not all the time, but I seriously don't think that has anything to do with this issue. They told me that when it happens again, to try turning the key to accessory mode for 10s then try to start it. I found this post and wanted to share my situation with the hopes that someone out there who might read it can offer me some advice. Many thanks for your assistance.

 

Something that might get overlooked: these vehicles have a fuel pump shutoff system. This would be an additional item to look at. My Owner Manual does not say what controls it - but it is likely either a computer controlled system or some other device. The Owner Manual also mentions that the air bag system is involved. Just a thought, as the problem has not been obvious for most of you doing troubleshooting.

 

This is for a 2002 3400L but I think it will still be close or the same. Unfortunately there is a ton of things that need to align for the fuel pump to get power.

ECU needs to be working. Ignition switch needs to be on. Relays need to be energized.

I would track the 12v through the system via diagrams below. Since the pump and ECU seems to be working (engine will run when pump is supplied direct power), I think you're looking at a bad wire, connection or relay.

The L-R (light blue with Red stripe) wire should have 12v since it is coming off the 20A EFI fuse from the battery.
Then after the EFI RELAY, the W-L (white with light blue stripe) wire should have 12v with the key on.
If not, this means the ECU isn't putting 12v on the GR-B (Grey with Black Stripe) wire which is the MREL (Main RELay) pin on the ECU or the relay is bad or a short or something else. I assume the MREL is powered when the key is on?
If the W-L wire has 12v, you are nearly there.
The C6 Circuit Opening Relay is the last piece. It is energized by 12v with the B-L (Black with Light Blue stripe) wire. This wire comes from the Ignition Switch and should have 12v with the key on. If not, then you have an issue there.
For that relay, the G-Y (Green with Yellow stripe) wire goes to FC on the ECU and that should be a ground. If it isn't...then the ECU, for whatever reason is not grounding that, maybe because of some other sensor?

That's the best I can do. Hopefully this diagram matches your car.

I urge people to get the factory service manuals which have the schematics and show locations of all junctions. I get the downloadable PDFs on ebay for like $15.

Left:


Right:

 

Oh, yeah, any aftermarket electronics?

Remove, disconnect all of them. They are always the source of evil.

 

I have been having a similar issue on my 2000 3.4l, I acquired it from my uncle after it had sat for 10 years and was mouse ridden. I tore the interior out and did a thorough service, including dropping the fuel tank and replacing the pump/sending unit. I put a few hundred km on it with no issue then suddenly it started die-ing randomly and not starting again. I'd leave it to sit for a day and it would fire right back up only to die a few minutes later and not start again. Today I replaced the timing belt/water pump/pulleys and it fired right up again after sitting all summer, I let it run for 5 minutes, did a lap around my yard then pulled it back in the shop where it died again and now will not start.
I unhooked the battery and am going to see in the morning whether it starts and then do the fuel pump power testing that has been recommended.

I also was wondering what a good way to delete my airbags would be?

Thanks in advance

 

I have a 2000 3.4 sometimes it will start up just fine sometimes it starts with a light misfire and sometimes it just keeps cranking like there’s no fuel getting to it. It has definitely been happening a lot more with the cold weather actually the first time it didn’t start it was around -10° C out so wondering if something went with that temp. But as of recently I’ve figured out how to get it to start I went and wiggled the efi relay and it started right up no misfire just a perfect start up so I replaced the relay and tried starting it and the same constant cranking problem happens. I’m onto something here would appreciate any feedback on what to do.

 

Sounds like the connections that the relay plugs into are dirty/corroded. Get some Electrical Contact Cleaner, and/or Isopropyl Alcohol, and scrub them out with an old toothbrush. Staggeringly useful tool for cleaning electric contacts. Use a pencil eraser to clean the connections coming out of the relay, then hit it with the electrical contact cleaner. If you can, pull the casing off the relay and clean the contacts inside with fine sandpaper.
You may need to access the actual connections the relay pins go down into, and tighten them up slightly. A gentle squeeze with a small pair of needle-nose pliers will do the trick.
Before you put the relay back in, a small amount of Dielectric Silicon Grease will help prevent a dirty/corroded condition for coming back.

You might also want to check the battery terminals, and the wires connected to them. Get a battery tool from any auto parts store. They have a wire brush, and hollow wire brush, in one handle. Maybe $2.00. Make sure the battery terminals are nice and shiney, both the posts coming out of the battery, and the terminals connected to them. Both positive, AND negative side. Check ALL the wires connected to the terminals are clean and shiney where they connect in to the terminals.
Be aware that the acid mist batteries outgas when they are charging, like right after you start the vehicle, can get under the wire's insulation if they're not heat shrinked down good and tight, so if there's any doubt, ohm the wires end to end. Any question, replace them. Better safe than sorry. Get some meltwall, or FIT-300, heat shrink, and slide it right on. The inner liner melts when you heat it up to shrink it down, and closes off the end of the insulation to keep the evil acid mist out. Do NOT use a paint stripping heat gun to shrink the heat shrink down, unless you keep a pretty good distance. They are WAY too hot to use close up.

Check both wires going to the starter are clean and snug. Check all the grounds are in good shape, clean and shiney. ALL the grounds.

Good fortune to you!
Pat☺