MikeyZee

It sounds like you have a fuel line blockage if you can run it from a gas can full of gas. There may be a filter back by the tank as well as an electric fuel pump back there. Make sure all the lines are clean and if there is a filter or a pump back by the tank make sure they are clean too. You have a mechanical fuel pump and that is why your car will run from a gas can. Some electric pumps have screens at the inlet and that could be clogged too. How is your fuel filter that is under the hood? Just a few things to check to get you started. My son's 240z had a few similar issues in the early going. Dirty fuel tank lots of sludge and clogged filters. Good luck, let us know what happens.

My son has a 72 240z and we are putting in a 78 EFI l28. We are really close and we were both hoping to get it running today. Before we pulled the 240z motor everything worked fine on the car with the original l24 and the auto trans it was a dog though. The engine is all installed as well as the 5 speed. We have done allot of work on this car and we are so ready to have it running. I was hoping to get it running today but I don't know if I am missing something or what. So far this is what we have installed. Parts installed from the 78 280z L28 5-Speed Trans ECU Manifold Injectors and Rail Fuel Pump Internal regulator Alternator Fuel Injection Wire Harness Umbilical Harness Dropping resistors Main EFI Relay Fuel Pump Control Relay Fuel Pump Relay As far as the wiring goes we had to merge the 280z and the 240z harnesses. I have studied both harnesses from the factory wire diagrams for the 72 and the 78. This is what we did as far as that goes. Fuel Pump Used the factory installed 240z auxiliary Fuel Pump wire harness tied in to the Umbilical Cord EFI Main Relay Plugged into the factory 280z Wire Harness Fuel Pump Relay WB to Fuel Pump Control Relay GL to Fused Battery/Starter Constant 12v (same as the Fusible Link would be) GL to Fuel Pump (+) tied into the Factory 240z fuel Pump Harness Fuel Pump Control Relay WB to Fuel Pump Relay L to the Alternator S Terminal BY to Starter Connection (Ignition Start) WB to Umbilical WB YB to Oil Pressure Sending Unit ECU to Body (Umbilical) L Ignition Box (Jacobs) Tach Connection GL Fuel Pump (+) Fuel Pump Relay WB Fuel Pump Control Relay BY Starter Connection (Ignition Start) We removed the Factory 240z Alternator and installed an Internally Regulated one. We also did the conversion steps by connecting the BW and WB then the W and Y together. We did not install the diode because the connector to the Factory 240z Regulator does not have the WR wire. The car was an auto transmission so it has the connections for the Inhibitor Switch. Do those connections need to have anything done with them? At this point we cannot start the car. It will not turn over at all. We can hear the relay under the passenger side dash clicking but that's it. The fuse for the tail lights also keeps blowing so I am sure I really got something screwed up! Anybody that can help or who has done this please chime in. Thanks in advance for the assistance.

I am working on getting my son's 240z working with a L28e swap from a 78 280z. In with the engine and trans was 4 AFMs. I have searched through to site and have found some mixed information on the AFMs I have. I am trying to determine which one would work with this harness. Like I said it is a 78 harness and the AFM socket has only 5 of the terminal pins of the 7 connected. Can anyone tell me what AFM that I have will work with the 78? I have read that if the AFM has 7 pins you can jumper the last 2 pins it should work too. Can anyone confirm that? Here is a list of what I have. A31-618-420 5 pins 80? A31-?582?-420 5 pins 78? Not real sure about this. The number is worn off mostly. A31-060-001 7 pins 75-77?? Has bypass port on flap A31-604-000 7 pins 77?? Has bypass port on flap Thanks for your help!

Hi all! I am looking for a front air dam for my son's 72 240z. We would like the MSA type II 2 or III 3 that covers the front bumper as well. You can contact me at mguzinski@gmail.com or 303-435-1866. Thanks, Mike

Thanks for the info BRAAP. I studied that post before. That does help clarify some stuff. I am not 100% sure If I am going to use the factory fusible links. I may just put some circuit breakers in there. So, it looks like I will need to grab the harnesses that plug into the relays. I still don't know how that umbilical harness is tied in weather it's independent of the dash/gauge harness or if it is integrated. Anyone who knows let me know. Anyone know if the 240z hard fuel lines will handle the pressure from the 280z fuel pump. Any success or failure stories to share? The lines on there are in pretty good shape, the tank has been boiled out last year and is in great shape too. Thanks All!

It looks like from the diagram the connections are for the ignition switched on, coil, ignition relay, and the fuel pump. Then they all seem to tie in to the connectors to the fuel pump control and fuel pump relays and fusible links even. I don't see the brake light connection. hmmm?

I do have a copy of the FSM but it doesn't really give me an idea of how the harness is tied in. figure (EF-41) is helpful but I'm not sure how the harness is separated under the dash that goes out to the engine compartment or from the fuel pump relay, fuel pump control relay, and fuel injection relay. I could cut and splice and make a harness but I would rather pull what I need from my friends car leaving what he needs.

We are going with EFI for drivability. We are at an altitude of about 6000 feet, going up the mountain passes can take you up to 10000 feet. We also frequently have up to 40 degree temperature swings in a days time. We do not want to sit there and adjust it once or twice a day. The SUs that were on there were junk and actually duct taped together and leaking fuel so they were swapped with old Weber DGVs early in the game. We picked up the L28e and most of the gear we needed and a 5 speed for $100 with the EFI as well as the ECU and harness. Now....that raises a new question though about the fuel lines. The hard lines won't hold the 40 psi or so put out by the 280z pump? I know the rubber hoses will need to be replaced. Thanks for the reply!

Hi All, My son and I are swapping a l28e from a 78 into his 72 240z. I have the wiring harness from the 78 as well as ECU, dropping resistor, fuel pump, fuel relay, ignition realy, and EFI relay. There is a 4 position plug downline from the ECU connection that plugs into the "umbilical" harness that I assume connects to the EFI, ignition, and fuel pump relay. Can someone let me know what else the "umbilical" is connected. Does it hook into the fuse block or any other relays? We have an outboard electronic ignition so we will not be using the factory 280z electronic ignition. I have looked through the 78 280z wiring diagrams but it seems not to cover that real well. Maybe I'm missing something. Since I don't have a 280 right here to look at it's a little tough getting my head around everything. I have a buddy that is donating me the wire harness because he's doing a SBC swap I just want to make sure I can get the harness and the relays out without causing him issues with his swap. Any diagrams or pictures would be helpful too! Thanks! Mike

You may be able to switch the carbs around and see if it's the carb or a fuel delivery issue. Check your filters too. A fuel pressure gauge might give you a clue too.

You can always use the universal bicycle shifter/brake cable stock. That stuff is pretty cheap.

You could also try feeding the carbs from a gas can instead of the tank. It may help eliminate certain parts of the system. I unhooked the fuel supply from the under hood filter and ran a hose into a jerry can to help diagnose. Good Luck!

http://forums.hybridz.org/showthread.php?t=138772&highlight=DGV+fuel+pressure

Hey, my son had the same problem with his 72 240z and the Weber DGVs. His problem turned out to be a dirty tank. We ended up having his tank boiled out at a radiator shop for about $100 and he has not had the fuel delivery problem again. When the fuel level got low enough it would suck up the dirt from the tank and clogged the filter under the hood. There were issues like the rear carb would not spray, the front would. We switched the carbs and they worked for a few minutes then the rear carb would stop working. Just blew my mind cause I knew we had just put a new filter on it. Like I said it was just when the tank got low. For the pump, you can just rely on the mechanical fuel pump and see if you can get it to run consistent. The electric pump was just to fix a vapor lock type of issue. The DGVs only call for a few pounds or pressure maybe 4-5psi. You could measure the fuel pressure at each carb and different places before and after the fuel filter and stuff.

OK....the other red wire....where does that go? and which wires go to the tach? maybe if you can draw a schematic of how it's wired now. I think there are 2 tach wires one should terminate at the ballast resistor and one on the coil as I remember I could be wrong.

Check this out.......... http://www2.zhome.com:81/ZCMnL/tech/MalloryDist.htm This is what you need to check. Let us know how it turns out!

Go up to MSDignition.com They have the schematic diagrams for each tach adapter on their site for download. You should be able to determine which one you need for your application. Do you have another ignition box on it or is the distributor points type? I don't think you can run without an electronic box if you are running electronic ignition. There may be a 12-80 module from a later Z on it to run the ignition.

Great advice all. I'm not doing the concourse stuff....and it has to be budget minded. There are not allot of places that plate or powdercoat in Colorado. It's going to be a driver. I like the information about baking the rails. I have seen some guys who do their rails and they are always flaking and chipping. Guess I'll be doing that tomorrow. THe rail is blasted, cleaned up and wiped down. Thanks again!

I used an MSD 8920 tach adapter. I am also using a Jacobs electronic ignition.

Looked at AtlanticZ and found the manual. That's all I needed!

You know how the fuel rails have that yellowish-goldish coating to them? Well I'd like to blast off that protective coating and paint them. What experiences have any of you had doing that? What did you use that stuck real well? I need it to be resistant to heat, chips and fuel. I'm thinking of using either engine paint, wheel paint, or caliper paint. Has anyone had any luck with these? I know Eastwood sells stuff but it's pricey. Thanks!!!!!!

Thanks for all the information. It is an early (wide ratio) trans according to the inlinestroker site and Jason (JBK) i wonder how it will run with the auto 3.545 R180 rear that is in the 240 now. I did find a couple parts cars with the R200 3.90 but want to get it on the road first.......Jason....any luck with the pedal box removal?

Hi All, We have a 5 speed that was with the L28 we got and would like to know what it came from. The only thing I can find on it is a serial number I think. I know there are many different 5 speeds wide ratio and close ratio. Does anyone know of a way to tell which one this is? I will post a pic later once I figure out how but the number is 7521128. Thanks! http://s808.photobucket.com/albums/zz5/mguzinski/72%20240z/?action=view&current=CIMG1357.jpg

We had this problem on my son's 72 240z. We had cleaned the tank but not flushed the lines or changed the filter. It was crud from the tank clogging the filter. When you said you cleaned the tank did you have it boiled out or what? There could be sediment still left in there. Just a thought. Good luck!