Over my head with a 73 Landcruiser 350 TH / 350 TBI Conversion

First I want to say Thanks for any help you can offer, I need it.

Here's what I have to the best of my knowledge. The Engine supposedly came out of an 87 suburban. When I pulled it, it was in an 80 crewcab. So I'm doing a conversion from a conversion. The Engine itself is a fresh rebuild and ran like a top when I pulled it. The ECM is # 1227747.The Crewcab had a manual 4 speed.

So here's the start of my dilemma's. When I got it none of the basic sensors "Oil / H20 " were wired to ECM. they were hooked to gauges. I'm not sure if there was a VSS or not. The rest of the "sensors" tied ECM to were plugged in. Like I said it ran like a top so I wasn't too worried at the time.

Question #1: Do I have to run the factory sensors? I would like to use my stock LC gauge's if possible.

Question #2: My ECM harness has the wire for the VSS pin A10. I know the wiring diagram says optional but do I need to do anything at all or just ignore it. I'm running a TH350.

I pulled all the wiring from the back of the fuse box to the ECM. However after reading several Threads I now know I'm missing the ALDL port and everything else inside the cab "besides of the ECM". There are the two plugs that go to the ECM. But there is a third 6 prong plug just adjacent to them I have questions about. I think I have identified a few of the wires but in an effort to avoid rambling on I'll just ask. Where the Hell does that go? I can't find jack squat about that plug.http://www.gearhead-efi.com/Fuel-Inj...cons/icon9.png Or I read it and I just missed it. I'm fried from the amount of hours I have been putting in on this build so thats entirely possible.

I have more questions but it's late and I'm tired.

This was my first post of any kind, anywhere. I'm not a techie by any stretch. Any help would be greatly appreciated.http://www.gearhead-efi.com/Fuel-Inj...cons/icon7.png

Great website it's been a huge help!!!

1. You do need to run the factory sensors for the TBI, but the oil pressure connector may be just a switch (a backup for the fuel pump relay) and is not required. As long as your fuel pump relay is working, you'll have no problems without it so you can install something compatible with your Toyota oil pressure gauge. For coolant temp, you'll have to run a second sender for your gauge. You can use one of the ports in the heads for that if there isn't something available near the thermostat.

2. You can run it without a VSS. There are some drivability benefits that go along with using VSS, so if you can add one, great. I've been running my TBI Blazer for about 12 years without it, I just have the park/neutral wire grounded. Someday I'll get around to adding a VSS, but just haven't felt the need so far.

Can you post a picture of the 6 prong plug? Or let us know where the wires are heading?

That age of engine ran separate sensors for the TBI system and for the gauges. You have to do the same.

You don't need the VSS, but it can run better with it.

The connector by the ECM sounds like it was for interfacing the TBI harness to the rest of the truck harness.

Thank you for you help. Sorry for slow response.."Work"

I went ahead and plumbed in the stock oil pressure switch and temp sending unit. I went to my local pick-n-pull and tracked down an ALDL plug. It turns out the ALDL plugged into the 6 prong plug next to the ECM that I wasn't able to identify.
I was able to get it running but only after I put a little fuel down the TBI. Once it fired up i stay,s running but once I shut it off it won't start with putting fuel down the TBI again.

I checked the Fuel pump relay, it appears to be working. I can hear the fuel pump run for about 10 seconds when I first turn the key. I can clearly see there is no fuel coming out while cranking. If put a few drops of fuel in it fires right up and TBI starts delivering fuel.

Any ideas whats up with that? I plan on putting a scanner on it today hopefully i will help me figure it out.

Thanks for the Help!!!!!

Double check that your ignition switched power is getting voltage in the "start" position. What you're describing is what normally happens when the TBI system doesn't have power while the starter is engaged. This is a pretty common (and annoying) issue when installing any fuel injection system. I've also seen this issue caused by a bad pickup coil or ignition module in the distributor, if the ECM doesn't know the engine is cranking, it won't fire the injectors.

Thanks Fastacton. You nailed it.

My ignition switch was dropping power in the cranking position. I have two switch's both did it.. WTF!!! I just decided to add a push button for the starter. Now it starts right up. I can't tell how well it's running yet. kinda tough with uncorked headers and no drive lines.

Thanks for the help!!!:thumbsup:

Good deal! I've had a couple of ignition switches fail right as I installed EFI, even after checking for proper operation! I guess it's asking too much for switches built in the sixties and seventies.