MikeyZee

I have a Megasquirt 1 pcb v3.00 that I purchased assembled and would like to test it on a stim before I install it. If you have a working JimStim or stimulator 2.2 you are wanting to get rid of let me know. I do not need the wheel simulator and all that so simple is good. Thanks, Mike mguzinski@gmail.com 303-435-1866

I think you would have to get another relay and put it in series to break the ground if no pressure making the ground. The way the factory one works is that if you are starting it will also complete the circuit. I don't think having the switch to battery power will work. It's like you would need a defeat in the event of no oil pressure and you still need to make sure you are making fuel pressure on start as well. That is what I am dealing with right now since my fuel pump runs constantly, key on, crank, no oil pressure. My fuel pump control relay is faulty and I have not been able to find a replacement. I'll let you know if I can come up with any specifics.

http://www.delcity.net/ cheapest I have found

ahhhh.....gottcha. Just making sure you have everything you need connected to make the "car" run and disconnecting that is not needed. Sorry I can't be more help but I feel your pain......

I'm not sure if you will need to keep the originals installed. I mean allot of the connections go to the factory ECU but are sometimes terminated to the harness in other places like to feed the gauges and things like that. I know the Fuel Pump Control only sends power to the ECU and then Powers the Fuel Pump relay. So, not sure if those would be needed. The EFI relay also sends signal to the factory ECU so not sure if that would have to be kept in tact to make the car run. Now, you are using EDIS right? So anything connected to the factory ignition may not have to be connected either I would imagine. I know allot of guys have used MS. It seems to be the preferred aftermarket ECU. I have seen a huge amount of post for it. Have you looked in the specific "Megasquirt" section of the forums? http://forums.hybridz.org/index.php/forum/34-megasquirt/ I wish I would have gone with MS after dealing with so many issues getting mine retrofitted. The guys in the MS know their stuff. It's been done before and I'm sure they can help more than I could.

I am not familiar with the Megasquirt but I know there are threads out there specific to that. I used the factory 78 ECU working in my son's 72. The fuel pump control relay and fuel pump relay should act the same. I know allot of people go with the outboard relays instead. The 78 relays are specific to the 78 and seems like they are not readily available. I have a bad fuel pump control relay and have not been able to find a working one so I will have to construct my own. The fuel pump control in mine is wired up like this: (If you have the harness that plugs into the relay for the color codes) Fuel Pump Control WB to Fuel Pump Relay (powers the fuel pump relay) L to the Alternator S Terminal (Engine Run??) BY to Starter Connection (Ignition Start) WB to Umbilical WB (signal to ECU) YB to Oil Pressure Sending Unit (shuts off with no Oil Pressure and not in start) 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 (+) (supplies power to the fuel pump) Just looked at the wiring for the Holley and truthfully that looks easier than the factory but same concept. I'm not sure if that will help you or if that's what you are looking for. The thing I had a problem with is sending the injection pulse to the ECU.

You mean like this? http://forums.hybridz.org/index.php/topic/86982-converting-a-current-driven-tacho-into-an-electronic-tacho/page__p__855735__hl__%2Bconvert+%2B280z+%2Btach__fromsearch__1#entry855735

The 78 has a fuel pump control relay and the actual fuel pump relay. Other years had the relay behind the kick panel on the drivers side. On the 78 they are both under that beer can shelf on the passenger side right in front of the battery. There is also the fuel injection main relay there as well as an inhibitor relay and a/c relay. I did not have the later two. The big relay is the fuel pump control relay which actually has 2 relays in one case. The next one from left to right is the fuel pump relay then the EFI main relay. I can't remember where I found it but I think it may have been on http://www.atlanticz.ca/ where I found the pictures of the relay bracket. I know it's in the FSM from http://www.xenons30.com/reference.html but sometimes those aren't the easiest to read. As far as the ignition relay....I left the original 240z one in the car.

Is your 260 an EFI or carb? If it's EFI here is a link on a previous post http://forums.hybridz.org/index.php/topic/17205-msd-6btm/page__p__125166__hl__%2Bmsd6a+%2B8920__fromsearch__1#entry125166 Check out the link in there with the hand written diagram. Also if you need the FSM it is available here. http://www.xenons30.com/reference.html They have all the factory wiring diagrams. Not sure about the 260 but on my son's 240z which has a different tach it was a little different.

I am looking for a CAI for a 78 280z NA EFI. I would prefer a K&N oiled type of filter. Please contact me email, PM, or phone. Thanks! Mike Guzinski mguzinski@gmail.com 303-435-1866

Here is a post that helped me. http://forums.hybridz.org/index.php/topic/37376-getting-your-early-240z-tachometer-working-with-an-msd-6-series-ignition/page__p__298874__hl__%2B8920+%2Bmsd__fromsearch__1#entry298874 It is real straight forward. Hey your in Colorado too? I'm in Parker.

I have checked the voltage and operation of the cold start and seems the thermo time switch may be bad. There is no continuity on the switch when cold, nothing changes at all on the switch from being in the fridge to being in boiling water. Bad thermo time switch. In Colorado mornings have been down in the 60s, soon to dip down into the 40-50 range within 2 months. I want to make sure it's pretty easy to hop in and just start. I have done some research and the thermo time switch actually completes the ground of the circuit and introduces a ground to the cold start injector to allow it to fire. If I ground the cold start injector while starting it fires right up. The #21 is filled in the harness but since the ground is handled bu the thermo time switch the wiring for that going back to the #21 in the harness is not needed, thus no connection to the ECU and no pin in #21 on the ECU. I have researched and it's the same ECU for 76, 77, and 78. Both of my ECUs are this way (A11-600-000). I have the 78 manual and looking at the other ones would just confuse matters since it's a different animal then the other years I have found. I know the fuel pump should not run when the car is in the on position when the car is not running and my problem with that seems to be a bad fuel pump control relay. The relay is a dual relay, saying that both must be switched on to get power to the fuel pump. My relay as tested will allow the fuel pump to run regardless of if oil pressure is present or not. Bench testing shows that is I power either side of the relay the circuit will be energized, either....not both. As an in car test I had the car running and unplugged the connection to the oil pressure sender and the engine continues to rum, thus a bad fuel pump control relay. These are not easy to find it seems and may have to make my own to make it work properly. I have heard that some EFI Zs will run the fuel pump for a few seconds when you turn the key to the "on" position to allow a "prime" but have not been able to confirm that for sure. I may have missed something from the EFI bible but that was written based on a 76 so some things are different. I am still using the Jacobs ignition and it is working flawlessly. It looks like I'll put the MSD in my Dakota if I'm not using it in the Z....bonus!!! The tach is still off but not real worried about that until we get the starting glitch, the fuel pump control relay, and a few other issues worked out. Although timing it accurately without knowing the actual RPM is well....impossible. We may go ahead and put a 280z tach in it to eliminate extra "stuff" under the hood but who knows at this point. All in all I think things are coming together nicely. Starts (with the jumper), runs, and drives this point, down to fine tuning at this point. I really appreciate all the help with these issues and could not have done it without all the help from the board members. The good thing about this board is that you get many different opinions on what may be wrong and sometimes helps you think outside of your box. Oh and thanks again for the tach adapter, that will help immensely! I guess at this point we can call this solved! Thanks so much again! I know my son is just so excited to get his Z with the new guts back on the road.

"With regard to your remaining car issues, I suspect your no start condition might be related to either (1) the fuel pump is not getting power on the key "start" position or (2) at very low (starting) rpms, the EFI box is not getting a strong enough signal on Pin1 to know to send fuel to the cylinders. I think in your thread you mentioned that the fuel pump was running in the start position, but the simplest way to check is to disconnect the fuel line after the filter and turn the key. Might be a little messy, but it's foolproof." The pump is running in "on" and "start" 13.2 V or whatever the battery is reading at that point. I just spray about half a shot of starting fluid and it fires up like a charm. I can fool the entire cold start system too by putting 12v + and - on the leads.....hear the injector click once then turn it over and starts right up. It just seems like the cold start system in my 78 is not complete with that #21 pin just not being on any of my ECUs. Maybe the thermo-time switch when energizes shorts against the ground and sends the signal back to the cold start injector. I checked to see if either of the pins on the thermo-time switch are grounded to the chassis and one is. That may be a possibility because the thermo-time and the cold start injector are in parallel.

Hey all. My son and I just got his 72 with a 78 fuel injected motor running. One of the problems we are having is that the cold start injector is not firing. I tested it by running direct power to it and it does click and sprays gas. When I did this and cranked the motor over it fired right up. Previously the only way to get it to start was to spray some starting fluid in it. I traced back the wiring and studied the diagrams and it shows that the leads run back to #21 and #4. These two wires also are connected to the thermotime switch according to the diagram and confirmed by a continuity tester. The problem seems to be completely wierd. One of the leads from the thermotime switch and cold start injector both come back to the #4 position of the ECU connector the other one comes back to the #21 position of the ECU connector. The #4 wire is confirmed to get power on start through the umbilical cord BY wire. The power also feeds to the cold start injector and the thermotime switch on start. The thing that is puzzling me is that the #21 position on the ECU connector has no pin on the ECU for it to terminate. The 2 ECU I have are a11-600-000 which is supposed to be the correct ECU. I also have another harness from a 78 and it is identical. Has anyone else noticed this? Do I somehow have the wrong ECU? I have checked to see if maybe there is a splice in the harness but there is not. Anyone have any insight or knowledge of how to get this working? Thanks All!

Thanks to everyone for the input and food for thought. I found a post earlier about the 8920 tach adapter and a neat little schematic. Like I said I have an 8920 for the 240z tach. I hooked hooked it up as the schematic says (added the switched power to the red lead). Then something that Pharaohabq said about it being 180 out. I thought maybe I got it off a little when I had the head pulled. We pulled the valve cover tonight and turns out the cam was lined up perfectly to the crank. Hmmm? But the dizzy was out 180. The dizzy was the 79 280zx dizzy that we had put on the L24 to convert it to electronic ignition. Guess we grabbed the wrong on! The ZX dizzy is 180 out from the 280Z distributor! Swapped it out for the correct one from the 280z and started to try to start. Sprayed a little starting fluid in it and fires right up! WOO HOO! It's just a little loud with the open header! The next thing we have to figure out is why it won't start without the starting fluid. The 78 280z wiring diagram has the position #21 connector terminated to the cold start injector and thermotime switch. Pin #21 on the ECU has nothing in there, no pin to connect to at all. The two ECUs I have are a11-600-000 and neither one has a pin in the #21 position. Any one run across this before? I have not actually tested to see if the cold start injector is working at this point. I'll have to check this tomorrow. If anyone has any insight about this please let me know. Another thing is the tach seems to be reading high. Barely idling at about 700 RPM (by ear) shows as it's at 1100-1200 RPM on the factory 240z tach. I have yet to put another tach on there but it just seems inaccurate. Wasn't there a cure for this by putting a resistor or diode in the signal line? If not I guess I can either get a 280z tach or a 8910 tach adapter for the EFI and use the 8920 for the tach. Any help is appreciated! Thanks all.

I am looking at some diagrams here (slacking off at work). One setup looks like someone is running the 8920 to the blue (signal for the EFI) http://forums.hybridz.org/index.php/topic/17205-msd-6btm/page__p__125166__hl__%2Bmsd6a+%2B8920__fromsearch__1#entry125166 I'll try that and see if that gives me any results but I am thinking I will have to revert that back to the configuration I have now and add an 8910 as well. The actual configuration I have now has the older 8920 with the white going to the tach signal from the ignition, black goes to ground, violet feeds the 240z current controlled tach and the red.....lol....no connection! Yeah, it's working and accurate. My son is getting restless to get his Z running again. He is a teenager and has no patience at all I don't want him to lose motivation and interest. I want to keep him motivated but we are in a "holding pattern" now. I'll PM you about the 8910.....Thanks!

tennesseejed- Thanks for the reply. I currently have a MSD tach adapter (8920) running the factory 240z tach. I am thinking I will need to run both a 8920 for the tach and a 8910 for the ECU/Fuel Injection pulse. I just acquired a MSD 6a and a SS blaster coil, a more standard setup always seems to help. I mean it's been done before. The output of the Jacobs ignition should be the same as the MSD but I'm not real sure. I thought the 8920 would drive the signal correctly for the fuel injectors if I read the other posts correctly. I read somewhere that someone was using both the 8910 and 8920 in a configuration like mine. The alternative of course is to convert to a 280z tach but then I would still need one adapter. Correct? Of course I'm more concerned with getting the engine running and the tach can come later.

This weekend we did many tests on the components of the EFI on the car. This is what we came up with. The fuel pump control relay powers the fuel pump relay whenever there is power introduced to the BW lead on the relay (ignition on) power and does not need to have oil pressure to power the fuel pump. Thus our fuel pump always runs. The fuel pumps also runs during start so I don't think this would be the problem with it not starting. The fuel injectors are not pulsing at all. The injectors are getting voltage with the key on. I do not get the injectors to pulse on the 3rd break. The EFI relay comes on so I did the tests outlined in the EFI Bible. All the tests show the wiring is good and the system is getting voltage where it should and there is continuity where it should be. I went ahead and bought another ECU as suggested in the EFI Bible. One of my concerns is maybe it's the electronic ignition I am using. I have a Jacobs Electronics CD ignition and then to get the tach to work we had to add a MSD tach addapter. The ignition and tach were both working on the L24 with the electronic distributor. I am sending signal to the tach and ECU with the tach wire from the Jacobs box. Is this a sufficient signal for the ECU? I did notice one thing about the ECU and connector. The ECU is a11-600-000 and the #21 has no pin however the harness has a connector in #21 which as I read is for the cold start injector. Has anyone else noticed this? Is the 78 ECU unique to the 78 or are other model year ECUs? I did a search and the a11-600-000 shows that it is for a 76-77-78. If anyone has any suggestions that would be greatly appreciated.

The plug wires are all on correctly and all that was done to the engine was a new head gasket was put on. Nothing was turned on the engine or head when that was replaced. The distributor is keyed so I don't think that can be in wrong. When it's firing I can't hear the injectors pulsing. I need to check them to see if they are getting power again. I wonder if the plugs are getting wet from the cold start injector only. Another wrinkle is that the fuel pump is always on when the ignition is on the run position. Maybe it's shutting off the pump when we are trying to start it.....hmmmm? I know that is not supposed to do that. I wonder if somehow I got those mixed up. The Fuel Pump Control relay powers up the Fuel Pump Relay which passes power to the Fuel Pump. I'm guessing the Fuel Pump Control Relay is not wired correctly or is faulty or stuck or something. I have wired it like this. Blue Wire=Alternator (L) Terminal Yellow/Black=Oil Pressure Sending Unit (I have this spliced into the original Wire for the Oil Pressure Gauge. I noticed a 2 terminal sending unit and the manual shows 2 terminals as well. Would this be the wrong sending unit I have installed?) White/Black=Connected to the umbilical harness White/Black and then has a 12v start and run powering it. It seems like we are so close but dang this stuff is not exactly plug and play...lol

OK....At this point we have fuel getting in the combustion chamber cause the plugs and they smell of unburnt gas. The plugs are firing too. We pulled the plug and on crank they fire. I have the fuel injection (blue lead) terminated at the tach output of the Jacobs ignition. The #10 pin is getting power on the ecu and the #5,16,17, and 35 all have continuity with the ground. The engine cranks over fine but doesn't ever seem to ignite. All the fusible links are fine and all seems to power up and shut down fine. Is there anyway to have the timing 180 off or anything? I'm at a loss here.....

Congrats on getting it running!!!! The main reason they put the rear fuel pump in was to prevent vapor lock and hot start issues from fuel vaporizing in the lines. Depends on how you are going to use the car I guess. It will run without it though just fine on the mechanical pump but may have issues listed above.

OK....looks like we got the no crank situation worked out but still won't fire up. I can't hear the injectors pulsing, there were a couple backfires so I wonder if that means we are getting spark. I have to check to see if we are getting any gas or spark for sure though. We ran out of daylight. The fuel pump however always runs once you have turned the key to the on position. The only way to stop it is to disconnect the battery terminal. We reconnect the battery terminal and it does not come on until you try again to start it. Thanks again!

I think we got the issue with the inhibitor switch straightened out. Just not sure if everything else is OK. I have not had the chance to short the switch connections and terminate the others on the reverse switch on the manual transmission. I did not see a neutral safely switch on the wiring diagram on the 78 280z. I do not have one on my manual transmission either. I am not sure the 78s had this safely feature but adding one may be a good idea. Thanks for the info!

Are you sticking with the auto trans or manual? The inhibitor switch is on the side of the gear selector of the trans. 2 leads going to it are to tell the car it can start in P or N. The other two are for your reverse lights. You can take the bracket off and just mount the needed relay(s) to the inner fender well. I'm not sure if any of the other relays EFI Main, Fuel Pump Control, and Fuel Pump relays are needed to tell the computer to keep running the car. I'm sure more will chime in.

OK.....now I feel kinda stupid. It looks like I made a mistake. I hooked up the kickdown connectors from the 240z harness to the reverse switch on the manual transmission. I just wasn't thinking. It also looks like half of the Inhibitor switch harness should be connected to the reverse switch on the manual trans. The other two look like they should be connected together to allow the starter to engage. Can anyone verify that for me though? I have looked at the 72 240z wiring diagrams but they don't have anything referencing the auto trans or inhibitor switch. The diagram for the 78 280z does have the detail on the inhibitor switch auto trans etc. It says for the 280z the wb and wb are the inhibitor leads and the g and g are the reverse leads. Are they the same color wires for the 240z? Thanks again.