Randall

Well I finally got a second hand to watch the timing. On cygnus's tune with 60 degree offset in ms and distributor fully advanced I saw 5 atdc at 700 rpm AFR read at 9 I then changed the offset to 45 and was seeing 15 atdc and idle changed to 1200 rpm with an AFR of 12.8. What is strange is that it ran super with the 45 degree offset great vacuum smooth idle good throttle response but the timing is off.

Yeah I had 5 in there when I set the timing so it is probably off by about 5

It's a brand new walbro 255lph pump so it should be fine. I am positive its probably just the old FPR that I am using. The only thing that still concerns me is the random cranking problems I am having. Looking at the log you can see where the rpms dropped twice while cranking and the one that dropped to zero also corresponds to a voltage drop from 11v to 10v. I wonder if this could be a starter issue? Can't be hydrolock as it started after i started testing spark but before i started adding fuel to the equation... P.S. i fixed the link in my sig

Yeah that is what I meant. Timing was fixed to 0 in the table and trigger offset was set to 60 then I turned the distributor until I saw 0 while cranking. It was late last night so I have not verified timing while it was idling

Yeah it's an LC-1 wideband. I cranked the car without the fuel injector fuses and the pump turned off. At a cranking speed of 300 I set the distributor to 0 using an offset of 60 with timing table set to all 0's First cranking timing I tried was 5 btdc and I had some kickback while cranking so I then changed it to 0 btdc and had two kickbacks as you can see in the log while cranking. I will change it to 10 btdc and see what happens. I think I will also pinch the return line just to make sure but I'm pretty sure fpr is bleeding because after it bleeds if I pull the plugs and crank no fuel blows out of the cylinders.

Keep forgetting to attach.... First_Start.zip

Sorry guess it didn't upload.... Yes it did start on about 2nd 3rd crank. I used cygnus's tune since he has a pretty similar motor setup... It ran ok vacuum was only about 11 or 12 and afr seemed to slowly lean out but thats for sure a fuel supply issue... The only 2 things I am concerned about are: 1. i topped the motor off with oil and cranked the motor to prime it with oil, especially the turbo. (i waited until i saw oil coming out of the oil feed for the turbo. At this point everything cranked fine. But when i started to get the distributor set to match my offset in megasquirt the motor would start to kick back every now and then like you would see when you have the advance set to high. Maybe im just getting some noise while cranking that is sending out a weird spark? 2. when i prime the system it hits 40 psi or so then will slowly drop to a little above 20 psi then if i come out within an hour or so it will be at 0 psi. I don't believe the injectors are leaking because they where not leaking when i bench tested them. So that leaves me with either the fuel pump is bleeding pressure which i also do not believe to be the case because i can disconnect the pre-pump filter and just a little fuel will come out when i still have pressure. So that leaves the stock FPR that i used? Unless this is normal? Also in cygnus's tune he has a req_fuel of 9.1 but mine calculates to 7.2 but we have the same injectors except my motor is bored over .40 and his is .20

I know I was just confused as i did everything by the book this rebuild. Last rebuild i screwed up and it was 180* out from me installing the oil pump wrong so i just moved the wires around like you stated.

Here is a data log of my first start up of my 76 280z. I think my fuel pressure is not consistent (probably need more fuel in the gas tank) Let me know if you see anything that sticks out. Link to my car specs is in my signature.

i think its about 300 for a standard rebuild but i added a t4 50 trim compressor plus shipping mine was close to 400. I bought all of my megasquirt from DIYautotune.com Matt at DIYautotune is very knowledgeable and helpful.

well i was going to weld it but i just filled the two slots for the advance with JB weld

Well I had to pull it apart anyway to lock the mech advance. The mech advance weights are attached to the offset at the bottom. The top section with the rotor and slots can fit on correctly or out 180 degrees. So I just rotated it 180 and filled the slots with JB Weld and then reassembled.

That's what I was going to check but was not sure.

So I am almost done with my second l28 build so I am very familiar with these motors. Except this one is being setup for a turbo instead of the triple webers i had on it. I was planning on locking out the stock VR distributor and using it to control timing using MS2. So i have a 280zx distributor from my triple weber setup and i also pulled a distributor from a 76 because i like the long tail coming off of the VR which will make wiring very easy. So onto the problem, the motor is all buttoned up still on TDC from setting the chain. I go to put my 76 junkyard distributor on and it is 180 degrees off!!!!! I was almost at a loss for words cause this is my second time at this. (on my first motor build the same thing happened except I had turned the motor after i set the chain so what a thought was TDC was not when i installed the pump) This time i know i did everything correctly so just out of curiosity i grab my 280zx distributor and it points dead on at #1 on the cap!!!!! How could a distributor be 180 off and another be correct?

so i have the 440cc supra injectors and when i calculate my req_fuel i get 7.2 Your req_fuel shows 9.1 i figured we would have had the same values since our injectors have the same rating. how did you get 9.1?

Here are some updated pics of the 76. I finally got the motor in and am still working on all of the wiring and piping. 76' Album - http://s596.beta.photobucket.com/user/longhorn262/library/76%20280z 77' Album - http://s596.beta.photobucket.com/user/longhorn262/library/77%20280z I decided just to post the albums since every time i post a link to the picture it disappears after a while.

So the verdict was that the 450cc where identical to the 440cc injectors. Im trying to setup MSII with 440cc supra injectors. I am guessing it should look like this with a v3.0 board: Injector Dead Time @13.2V(ms) = .9 Battery Voltage Correction(ms/V) = .2 PWM Current Limit(%) = 75 PWM Time Threshold(ms) = 1.2 Injector PWM Period(us) = 50 Didn't see battery voltage correction anywhere so i just left it at .2

http://www.store.partsdinosaur.com/page278.html This guy was a pleasure to work with and the cheapest i could find when i ordered ITM dished pistons for my turbo setup... Also a cam regrind is another good route. There are a few recommended places to have your stock cam regrind just search. BTW datsunllc gets a thumbs down from me and don't ask why

just curious what the final results were on this. Im going to be running MS2 v3.0. I plan on using the stock VR from a 280z instead of forking out the cash for a turbo distributor. Hoping i wont have any problems with this.

EGT = Exhaust Gas Temperature EGT will be hottest at stoich which is around 14.7:1 If the car is running leaner or richer than 14.7:1 EGT will decrease considering everything else is constant If you retard the timing EGT will go up If your exhaust is glowing your EGT's are probably 1600 degrees F or higher which they shouldn't be when operating normally. 1. Check timing and set idle to 800 (meaning no vacuum leaks) 2. Check your plugs after letting it idle. (if you dont know what to look for use GOOGLE) 3. Check your plugs after driving it hard(try not to let it idle after this period) 4. Check compression You should be able to tell a lot from the last 3 on what is causing problems. I had a rough idle on my dads 77 that we just acquired so i immediately pulled all the plugs and saw one was black with slight oil so i believed it was not getting fuel so i swapped in a used injector that i knew worked and problem was solved.

Yeah when I first bought the car it came with a 12 lb Tilton Flywheel. My dad just bought a 77 280z stock and I have been driving it but i cannot tell a huge difference. I think im going to leave it stock and see how I like it.

Sent if off to Joel @ Arizona Turbo & Tractor Supply Did an awesome job, fast turn around. I highly recommend them.

PM sent. Yeah it is crazy how deceiving that image is didn't realize it when i posted them. Should have taken them sitting flat but the lighting would not have been as good wanted you to be able to see the condition of the skirts and ring lands.

Just measured all 6 exactly 3 and 1/16 of an inch long...was curious why you would think a stock P79 nissan flat-top would have different lengths but picture angles can be deceiving.

That's the camera angle cause they are all stock p79 pistons from nissan ill measure when i get home but when i reinstalled them after the rebuild there was not a specific order i reinstalled them in and there was absolutely no vibrations what-so-ever