Need help getting it running!
Thread Starter
Teching In
Joined: Apr 2002
Posts: 17
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From: Dallas,TX
Need help getting it running! I am putting an LS1 from a 2001 TA into a 1972 Datsun 240Z. I am using the stock LS1 fans, column, fuel tank, and gauges. I have it all hooked up on th garage floor. It cranks but won't fire. The fuel pump only works when the OBD scanner is plugged into the port. It still won't start. The funny thing is, the scanner shows no codes. Can that be possible since I don't have the rear O2's plugged in at all? What can I do to get this thing running? I have the GM service manual on CD-rom but I can't figure out what I am missing. Column and key should take care of the VATS and I even have the clutch pedal CPP switch hooked up. HELP PLEASE! 
TECH Apprentice
Joined: Oct 2002
Posts: 321
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From: Woodstock, IL.
Re: Need help getting it running! "Column and key should take care of the VATS"
Not if you don't have a BCM. The PCM gets its signal from a separate computer called a bcm . The BCM is what reads the key resistance. If it fires then dies it sounds like VATs
It will run without rear O2's If you don't have the BCM many including me can explain to you how to make a vats box that sends the 50Hz signal to the PCM. You have come to the right place. There are allot of knowledgeable people on this board
Not if you don't have a BCM. The PCM gets its signal from a separate computer called a bcm . The BCM is what reads the key resistance. If it fires then dies it sounds like VATs
It will run without rear O2's If you don't have the BCM many including me can explain to you how to make a vats box that sends the 50Hz signal to the PCM. You have come to the right place. There are allot of knowledgeable people on this board
Thread Starter
Teching In
Joined: Apr 2002
Posts: 17
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From: Dallas,TX
Re: Need help getting it running! I do have the BCM. From what I have read in the manual, fuel pump and starter are disabled until the key is read. Thanks for the help though. Any other ideas?
TECH Apprentice
Joined: Oct 2002
Posts: 321
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From: Woodstock, IL.
Re: Need help getting it running! Are you sure about the fuel pump???? I thought it just disabled the injectors on V8's and the starter on V6's. Will it run on starting fluid? If you have a fuel pressure gauge you should have 55 psi at the fuel rail. Other things to check it that all pink wires have 12v when the key is in the start or run position, and the orange wire has 12V always
Thread Starter
Teching In
Joined: Apr 2002
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From: Dallas,TX
Re: Need help getting it running! Thanks again, its been a while since I read the manual. It very well could be the injectors, in which case, the starting fluid idea is a good one. I don't smell gas at all when I crank the engine, so the injectors may not be working. Does that mean the VATS is still preventing starting? It shouldn't be. Also, do you have any idea why the fuel pump only works when the OBD scanner is plugged in?
Teching In
Joined: Oct 2002
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From: Salinas
Re: Need help getting it running! Hey Maichor
See if i can help you out here. I know for a fact that the fuel pump will turn on if you turn to acc. If it isn't turning on it could be two things. The connection to the fuel pump relay which you said worked with a scan tool, or VATS which will shut off the fuel pump and injectors but it should still run at least for 3-5 sec. Remove the fuse for a min or so and try it again. Try perminatly connecting the fuel pump and turning it over.
In the service manual look under Theft Deterrent
Good luck
See if i can help you out here. I know for a fact that the fuel pump will turn on if you turn to acc. If it isn't turning on it could be two things. The connection to the fuel pump relay which you said worked with a scan tool, or VATS which will shut off the fuel pump and injectors but it should still run at least for 3-5 sec. Remove the fuse for a min or so and try it again. Try perminatly connecting the fuel pump and turning it over.
In the service manual look under Theft Deterrent
Good luck
Thread Starter
Teching In
Joined: Apr 2002
Posts: 17
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From: Dallas,TX
Re: Need help getting it running! Thanks Bri, haven't seen you as much over at Hybridz. How is your car running? I won't be able to attempt to fix mine until this weekend. I will try all of these suggestions. By the way, fuel pump does run for the 2 seconds as programmed to do.
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Thread Starter
Teching In
Joined: Apr 2002
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From: Dallas,TX
Re: Need help getting it running! OK! I have found the problem, sort of. The fuel pump still only works when the scan tool is plugged in, that bothers me. But, have fuel to the rail but injectors are not working. The pink wire seems to have 12 Volts all the time and the blue one increases in voltage as I crank the motor. Still none of the injectors are firing. I am going to try to get a fuel pressure guage today to see how much pressure. Is it possible that all the injectors are clogged? The motor has been sitting for two years.
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Re: Need help getting it running! That is the VATS. I had the same problem on my 93 RX7 swap. I didnt have the issue with the fuel pump mine runs for 2 seconds when you turn it to accessory so cant help you there. The VATS does nothing to the fuel pump but wont let the injectors fiire from the PCM. BTW you should see 58-60 psi for the LS1 but VATS IS YOUR PROBLEM. Two ways around it, buy LS1EDIT or the VATS bypass tricks. I went with EDIT.
The O2 sensors dont effect anything as far as starting the car but the car will run constantly in open loop mode unless it gets O2 readings from the front O2 sensors.
Mike
The O2 sensors dont effect anything as far as starting the car but the car will run constantly in open loop mode unless it gets O2 readings from the front O2 sensors.
Mike
Launching!
Joined: Dec 2001
Posts: 259
Likes: 1
From: Durham, NC
Re: Need help getting it running! I don't think VATS affects fuel pump relay signal. It just cuts power to the injectors. There are several pink wires and there are 2 orange wires. These all need to have power in ON position. The pinks are switched, orange are wired to the battery (well, fused of course, just not switched).
Make sure that these wires also always have 12v+ when the key goes to START. I had a major head scratcher due to what turned out to be a bad switch. So, when I turned it to ON, the wires had 12V+, but in the START position, they all went dead. Sucky that.
Injectors should see high, low, high, low, li ke a sine wave - 5volts I think?? Anyway, you can check this with a volt meter. The motor should start without VATS, it'll just die after 2-3 seconds or so.
There was a looooong thread that I started here about 4-5 months ago concerning my problems. People put out a ton of good suggestions. I suggest finding that thread and trying all of those. Just hit my profile and search thru all my posts - there aren't that many.
Make sure that these wires also always have 12v+ when the key goes to START. I had a major head scratcher due to what turned out to be a bad switch. So, when I turned it to ON, the wires had 12V+, but in the START position, they all went dead. Sucky that.
Injectors should see high, low, high, low, li ke a sine wave - 5volts I think?? Anyway, you can check this with a volt meter. The motor should start without VATS, it'll just die after 2-3 seconds or so.
There was a looooong thread that I started here about 4-5 months ago concerning my problems. People put out a ton of good suggestions. I suggest finding that thread and trying all of those. Just hit my profile and search thru all my posts - there aren't that many.