HI,
I have a 97 with 345 on it, it always runs perfect. Went to work ran fine, come out to go home, turns over no start. Checked then swapped EFI Relay, as well as the relay lower left that people call the fuel pump relay, OBD fuse, ECU Fuse, all of them are good, Checked the ECU as to the power and it has power. A few times while troubleshooting it seemed like it wanted to start so I shot voltage to the fuel pump and it had voltage while cranking, so I said what the heck and installed a denso fuel pump. No Fix. Since the beginning of this the OBD2 port has power but no communication with a known good scanner.

I ordered a used ECU off of ebay, anything I'm missing? It takes a week to get the ECU but if it isn't the issue hate to wait a week.

Thanks in advance.

Steve

The sensors that can cause a no-start condition that I can think of off the top of my head are: Crankshaft Position sensor, Camshaft Position sensor, Mass Air Flow sensor. However, the fact that you cannot communicate with the OBD-II system is a major issue. I would start by double-checking all grounds in the engine bay. Remove the wire, clean it, inspect it, clean the firewall or fender and then reattach. Do the same with the battery terminals as well. Make sure the diagnostic port on the right side of the top of the engine is also grounded to the side of the intake plenum - that is also a key ground for the system and would affect the OBD-II plug in the interior of the 4Runner.

Let us know if you find any suspect grounds. We need that OBD-II port functional to help any more than that.

I'll check the grounds, pulling up the prints to go through the ecu a wire at aq time, but since its a DD with nothing done for a year, I get the sense something failed. So ECU is best guess at this point, i'll let you guys know,

Did you check that the OBD connector is getting power? That connector gets power from the 7.5 amp OBD fuse so also check that fuse with a test light on both terminals. IF you had a bad ECM you should still have communication with the other modules on that network.

I bought a FSM and the troubleshooting guide walks you through the steps. Everything was checking out except no start, and no communication with the ECU from the OBD2 port.

I against my own advice changed the fuel pump, obviously didn't fix it. But now I have a new one.


So ECU guys, they do occasionally fail.

Thanks for everything.

Steve

No. The ECU s mostly do not fail. Can one sure but it's extremely rare..

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Wow! Good to know and glad to hear you are back up and running again. I'd be curious to remove the back off the old ECU and see if anything is burned up on the board.

I've thought about this a lot, there was a lightning storm, and a hit was close to the 4Runner, I wonder if possibly.... I'll do that. Curious what it shows

The lightning should not have affected the truck at all. Lets face it, it sits on 4 really big insulators. Sometimes called tires.

Having said that, if it was raining hard enough that water was cascading off the truck and onto the ground, the electricity could have taken it as a way up into the truck, bypassing the insulation of the tires. By the same token, the ground is a lousy conductor, so it doesn't take a whole lot of distance to attenuate the bolt to where it can't bother your truck at all.

Also, if you had a wire to something dangling down onto the dirt...

Does my rambling help any? When I was the lead Electronics Technician for the Aerostat Site in Yuma, Az., I got ahold of a number of books put out by NASA regarding lightning, and all it's tricks. Fascinating what it can do, it really is. A lot of technical info, and a huge number of pages to read through, but well worth it.

Good luck to ya. Check the ECU for burnt runs, burnt diodes and capacitors, and other components. As a general rule, they will be visible to the naked eye, without needing a multimeter to find.

Pat☺

I know of one car being hit by lightning in a parking lot. They did everything to try to fix it. New harnesses etc. Nothing worked and they ended up junking the vw sport utily and I think it was one year old at the time.

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One out of how many cars in open parking lots, not to mention how many cars in America alone?
I'm not trying to imply with all my rambling that it won't happen, but that it's very rare, and unlikely to happen to any one vehicle in particular. I was saying it CAN happen, under the right conditions, but it's unlikely to happen to any one car.

If it DID happen, I wish you all the best luck in repairing your vehicle...
Pat☺

No burns or anything obvious guess it just failed weird

We've had several lightning strike vehicles in the shop the last couple months. Multiple modules got fried. Vehicles can get struck by lightning.