Chevy Vortec v8 will crank, but won't turn over

I have a 1978 FJ40 landcruiser with a (~98 or so) Chevy v8. It suddenly refused to start last week for no obvious reason. It will crank and sounds like it wants to start and then dies. Tested the fuel pressure and it is getting 60 lbs. Sparks are firing. Does anyone have any ideas on things I should check?

Pull one or two plugs after attempting to start it. Are they wet with gas or bone dry? If they’re wet, better check that spark again. Then check to make suure the cam is turning by doing a compression test. If they’re dry, spritz some starting fluid into the intake and see if it tries harder to start or even runs momentarily. If it spits or starts and then dies, you have a fuel delivery issue. 60lbs at the rail means the pump is running. So why aren’t the injectors firing? Use a noid light to check for injector signal from the controller.

Got it to a shop and plugged it in. Learned a couple of things. First, This is a 98 Chevy Vortec V8. Second, it wouldn’t start because it had fallen into ‘security mode’. 98 was the first year that Chevy put this security feature in, tied to a chip in the ignition key. This particular installation (78 Toyota Landcruiser) does not have a Chevy ignition key. Instead, the designer of this system has a USB plug under the dash which is designed to provide the same amount of resistance as a factory key. If you don’t plug in the USB dongle before you try to start the engine, won’t start. Do that x times and I assume it goes into security mode.

Sorry for the long lead-in, here’s the question. Has anyone ever heard of this USB modification? Would love to know what you know. Second, is there any way to get a 98 Chevy Vortec ECM out of security mode without a trip to a Chevy dealer?

Thanks!

I am a little confused. Who put a 98 GM engine in a Toyota Lancruiser and why did they bring the secutity system with them when they did the swap?

I would not have brought the GM PCM and harness and all when making such a swap,I would have bougt all after market F.I and ignition pieces.

A GM v8 in an old Toyota Landcruiser is not an unusual modification. All the bolt patterns match, so it makes it relatively easy. What is unusual, as you observe, is the ECM installation with the USB fob.

If I were to replace the ECM, what aftermarket ignition pieces (brands) would you recommend for a high performance refurb?

I can’t reccommend any from personal use just from reading about them. Check out the Summit racing catalogue or web site. There is probably 3 main stream manufactures of F.I systems for you Toyota (or heavans forbid a carb)and many other ignition choices.

That was a lot of work to bring the GM injection over, you may want to consider staying with it and fixing it (eliminating problem pieces and keeping the good,sort of like what GM “restructuring” did)

98 was the first year that Chevy put this security feature in, tied to a chip in the ignition key.

VATS goes back to the 1980s. I believe you have the PASSKEY variant.
Here’s a short description of it- http://www.thirdgen.org/vats_passkey_system

Google on VATS or PASSKEY and you’ll find plenty of info on it.

Second, is there any way to get a 98 Chevy Vortec ECM out of security mode without a trip to a Chevy dealer?

All versions I am familiar with time out automatically after a preset period. Something like 5-15 minutes.

Has anyone ever heard of this USB modification?

Nope but sounds like a good way to use the OEM controller but not have to install the ignition cylinder hardware and harness.

I have never heard of USB in automotive but the IEEE 13** (I can’t memember the last two numbers) also known in the computer biz as "firewire"is used.