76 280z microsquirt project

[darom]

Hi guys,

I will be working on installing microsquirt v3 in my California edition '76 280z stock car which came with EGR/catalytic converter and an exhaust manifold. The car runs fine with the exception of typical lean conditions which gets resolved with a potentiometer pot.

 

The plan is to do it in 2 stages:

Stage 1 (getting "my feet wet" with learning to tune the car with TS):

Milkfab's 36-1 wheel (crank pulley mounted)

Microsquirt v3 + IAC stepper adapter

LM7 truck ignition coils

Pro Tunerz fuel rail (14mm) intake/throttle body/GM ICV

14point7 spartan 3 v2 wb

keeping stock exhaust + LSU 4.9

high impedance injectors

 

Stage 2

Headers + Turbo upgrade

 

In my infinite wisdom I figured I would kill both birds, aka project stages, with one stone - and purchased the Bosch 440cc 'green giants' injectors EV1 (part 0280155968), length 65 mm, Long style. Flow: 43,5 PSI (3 bar) 430cc / min = 41 lb / h. My assumption was to use them on a stock engine, get a turbo installed later, and re-use them. I got a great deal on them and they are authentic Bosch.

 

After reading the mega manual, now I am concerned about the idle pulse width issues and fighting over enrichment conditions running a stock L6 engine. I spent a lot of time going through this forum looking for anyone running similar injectors on an n/a engine and found that in almost all cases guys are running turbo engines with large injectors (supra injectors are popular).

 

The stock engine needs 15 lbs/hr or 158cc injectors. Obviously the 440cc ones I got are a major overkill.

 

Am I over stressing over the issue? Will i be able to tune these injectors for the time being?

 

Or I should keep on looking for 190-200cc injectors on Stan Weiss's site at http://users.erols.com/srweiss/tableifc.htm ? I found a few leads by cross referencing the part numbers and what rockauto has in stock. A lot of GB reman and BWD ones.

 

Do you have any recommendations? I'd like to keep 14mm/14mm top/base long, high impedance injectors, preferably Bosch.

Thanks!

Den

 

 

 

 

Edited July 15 by darom

[madkaw]

Since you will have made the effort of a fuel rail and use high impedance injectors why not go to a pick n pull salvage yard and buy some cheap used Bosch that are a bit smaller . Can’t tell you if 440cc will work or not . I run them in my 3.2 NA but I have 230 rwhp . I think before these I was running 36lb VW injectors . I moved the 36 lbs ones to my 720 truck that probably has 115 hp at the rear wheels - no issues 

[darom]

Thanks, madkaw. I might be able to squeeze by with these injectors. I will test them. If they run too rich, I will start looking for a set of cheap smaller injectors.

 

I need to start documenting the progress otherwise I just procrastinate.

 

Last week-end I made the coil bracket out of 2 chevy truck ones (came off LM7 truck), they overlapped nicely to get an idea where to cut/weld together. Fit mock-up, I might need to move it to the right side to align spark plugs better:

 

 

 

The coils will be grounded to the bracket to the welded bolt behind, the bracket is bolted on the right side to the cylinder head (black wire, ground to engine block). The coil bank connector will be attached to the same location as where Chevy put it originally (left side, there is a clip between coil 5 and 4).

 

The 1st cylinder's spark plug is too close to the coil, will have to lift the bracket up by 1-1.5 inches to make the spark plug wire fit. I ordered a set of spark plug wires to play around with:

 

And a simple visio wiring diagram for the coil plugs:

Edited July 22 by darom

[darom]

Made little progress by fab'ing a relay board for the MS to be installed in the stock ECU location.

A plate:

and the ready to be installed the relay board:

The stock plastic ECU cover will cover up the board.

 

The diagram of the relay board:

 

Finished the coil wiring (cables are exposed for now in case there are any issues). Readjusted the coil bracket to give more room for the plug No.1:

 

[darom]

I made some progress, installed the oxygen sensor. I had to drop the exhaust, fortunately last time I did it, I had used antiseeze on the threads, the manifold exhaust nuts were easy to take off:

 

The Protunerz' intake, my Bosch injectors and rail are in place. The throttle cable from 240SX took a while to adjust. The pedal didn't have enough angle to do a 100 percent open throttle blade opening. I ended up shimming the gas pedal's 'pedestal' to give additional room for pedal to go. The floor pedal adjuster is almost bottomed out:

The fuel pressure regular is going to be mounted by the battery. I bought all the right AN parts to attach it to the fuel rail, however I have major concerns about open exhaust below/dripping fuel from another source. If it drips, it will drip on the passenger side I am waiting for the AN 8 ORB to 5/16 barb (rail) and AN 6 ORB to 5/16 (regulator) to be delivered to move it to the new place.

 

I am having hard time finding a silicone hose reducer (3 in to 2.75 in, or 75mm to 70mm) to use my stock air filter with my new throttle body. I can find the right size, but not the length. I need a 12 in long 45 degree reducer hose, the longest I found were 8-10 inches:

 

If you guys know a place that can custom make or already sells a pre-made silicon reducer hose that size, please let me know. Thanks.

 

Edited September 2 by darom

[darom]

Forgot to mention that I had installed the MilkFab's trigger wheel that gets mounted on the 280z a/c harmonic balancer. This is their picture (I didn't take one):

 

Last time I changed the timing chain (6 years) ago, I advanced it by 4 degrees, the notch is to the right of the cam gear mark:

 

The MilkFab's instructions are calling for centering the sensor on the 6th tooth: "Adjust the trigger wheel while the mounting screws are loose to align the center of the sensor to the center of the 6th tooth if using the 36-1 wheel."

 

I couldn't get the 6th tooth aligned (not enough adjustment), I could center it on the 7th tooth. I thought I had done something wrong. Searched the forums and found Chickenman's post (whose opinion I respect on this forum), who is recommending to use 7th or 8th tooth: "The missing Tooth should be 7 - 8 Teeth ahead of the sensor. Each Tooth = 10 degrees. So missing Tooth has to pass Crank sensor 70 to 80 degrees BEFORE TDC. This is very important. Re-position Crank wheel to get the missing Tooth ahead of Crank sensor by 7 to 8 teeth Minimum. "

So my understanding is that my setting is at 60 degrees before TDS plus an additional 4 (physical cam advancement), 64 degrees.

36-1 wheel is a 10 degree per tooth. We need to count gaps. I placed mine on the 7th tooth, 6 gaps, i.e. 60 degrees (plus 'built-in 4 degree advance), 64 total.

 

I hope I got it right.

[darom]

Morning,

I ended up getting a 3" exhaust pipe tip and welding it to my stock air cleaner box:

 

The relay board is installed, I left some fuses out while setting up the initial timing, the board will be covered with a stock ECU plastic cover:

 

I installed the Microsquirt ECU on the passenger side to separate wires carrying 12V for inj/ign/WB etc from the relay board on the driver's side. This is a fabbed bracket:

and in the installed position:

 

Reflashed the stock ECU firmware with the msextra code, all sensors are calibrated (with the exception of the Spartan3 WB). The GM IAC will be worked on later while I am setting up idle.

The coils passed the test from the TS. The LS2 truck coils are set at 3.5ms dwell per the manual.

Edited October 18 by darom

[darom]

Now  I am overthinking the initial timing configuration. My hall sensor is pointed at the 7th tooth. I found some posts advising to count the gaps and official doc saying I have to count teeth.

If I set my Tooth #1 Angle (deg BTDC) at 70*, and command 10* at fixed, my advance timing light is at 10* - I get sync between the pointer and my harmonic balancer mark.

 

I am confused about my timing chain/cam sproket 4* advance that I did years ago.

 

Can someone please tell me if I need to add these 4 degrees to the 70* to have a "real" 10 degrees since the ECU is not aware of the mechanical cam advancement? If I use 74 degress for 36:1, 10 degrees fixed, my advance timing light at 10 degrees, I am off my pointer/balancer mark.

 

Appreciate your input. Thanks.

[darom]

I re-read Chickenman's post here:

and set my 36:1 to 70 degrees, fixed timing at 10, the advance timing light at 0 degrees, and I have the timing pointer properly synced with my balancer's timing mark. I am still looking for those 'missing' 4 degrees

 

Found another thread on setting up initial timing here

"Please note this is nothing to do with cam timing or mechanical advance etc. you can set these independent of the bottom end using a vernier pulley."

I guess I was confusing 2 different things here.

Per that poster's write-up, the advance (variable) timing light needs to be set at double degree setting due to the wasted spark mode. So if I am commanding 10 fixed, the light should be at 20 degrees.

 

Edited October 18 by darom

[darom]

I was able to run the car with 70 degrees trigger crank wheel, 10 fixed. With advance timing light set at 0 degrees, I was seeing synced timing marks. Now, back to the previous post about doubling the timing light to 20 degrees to check my timing? Is it needed or I am good to go?

 

I turned off the fixed timing, the car ran very rich, stumbling. I realized my MAP sensor (intake mounted unit from a used LS1 vehicle) was not working, it was stuck on 100 kpa. I am going to get a GM wall mounted unit.

 

Saga continues. Thanks!

2024-10-18-auto-timing.mlg

Edited October 18 by darom

[darom]

Found some posts suggesting to use 0 degree fixed timing, this way I am avoiding any issues with timing light/wasted spark results. I don't have any timing marks (-10 to 10) besides the timing pointer I got with the trigger wheel.

Tested with 0 degrees fixed advance and 0 degrees cranking advanced using 2 timing lights (old school with a variable knob on the back and the modern electronic one set at 0), both showed the TDC. My 36:1 Tooth #1 Angle (deg BTDC) was set at 60 degrees.

Edited October 19 by darom

[NewZed]

On 10/18/2024 at 11:45 AM, darom said:

So if I am commanding 10 fixed, the light should be at 20 degrees.

 

On 10/18/2024 at 10:25 AM, darom said:

command 10* at fixed, my advance timing light is at 10* - I get sync between the pointer and my harmonic balancer mark.

 

Not sure exactly where you're going or what the current problem is, but I think that the first comment above is incorrect, and the second one is correct.

 

Also, you were talking about cam timing and ignition timing together at one point (the 4 degrees thing).  They are completely separate as far as spark goes.   You could move cam timng all over the place by switching holes on the sprocket and it would not affect when the spark occurs, relative to crankshaft  position.  Timing sensors are all measuring where the crankshaft is in its rotation.  Cam timing is also relative to crankshaft position but adjusted separately from ignition timing.

 

Just some hopefully helpful commentary.  

[darom]

Thanks, NewZed. Appreciate your input. I did arrive at the same conclusion about the cam timing finally - two different things. Appreciate confirming it. I was way overthinking it lol.

 

I think I finally nailed the initial timing config using 0 commanded degrees in the Fixed Timing section of the TunerStudio. I set 60 degrees in the 36:1 section, tooth #1 Angle (deg BTDC), which confirms Chickenman's statement about counting the gaps times 10 degrees for 36 trigger wheels (I have 6 gaps, 60 degrees). If I count teeth, my hall sensor is pointed at the 7th tooth.

 

Question: I checked some of the guys' tunes on this board (cyrgnus and madcaw's) being curious about their total timing on their engines, and most of  them have 41-43 degrees by 3000 rpms. I have a stock n/a engine with a N47 head, should i go with a more conservative number like 36-38 degrees?

[NewZed]

You have to look at your MAP tables.  At high vacuum (low pressure) you can run more advance for a cleaner burn and better efficiency and better throttle response.  At higher RPM under open throttle most people have found that about 34 degrees is where you get the most power.  You can read a bunch in the L6 FAQ sub-forum about having timing set "all-in" at about 2500 RPM or various numbers around that.  Meaning that it stops advancing and just hold at that advance number from there to the high limit.

 

If I was starting with an MS tune I might first just mimic a stock engine's timing curves.  Nissan provides them in the Engine Electrical chapters.  You have to do some translation.  And the charts are in distributor speed so that's where you have to do the doubling.  From back in the days when they had distributor tuning machines.

 

The early FSMs have an actual graph.  Later ones have just a table and let you imagine the lines.

 

Here is 72 and 78.  78 would be like your engine probably if it's a stock 290Z engine.  They have different options for different markets and different transmissions.  Generally, lower advance is for emissions states, like CA.  Reduced timing is cleaner.  notice that they give the starting point, zero degrees at XX RPM.  So the first entry shows vacuum advance starting at 200 mm Hg, and increasing to 15 engine RPM at 350 mmHg.  Centrifugal starts at at 1200 RPM and rises to 17 degress at 2500 RPM.

It's like a mini general physics course.  It can be confusing, especially since centrifugal is tied to crankshaft rotation but vacuum is just tied to air pressure in the manifold.  Sometimes I still wonder if I'm thinking about it right.

 

It's easier to grasp if you have a stock distributor on a running engine with a timing light to learn on.  Good luck.

 

1978 EE chapter.

 

1972 EE chapter.

 

 

[NewZed]

This part of the Megamanual might help.

 

https://www.megamanual.com/begintuning.htm#spark

 

https://www.megamanual.com/ms2/tune.htm

[darom]

Great, thanks!

[madkaw]

Be conservative with the timing under load . Yes the engine can run at 45 degrees at light cruise with low Kpas . I would agree that 34 at full load is more realistic . Make yourself some detonation headsets and listen to your engine . Make adjustments accordingly 

[darom]

Sounds good, thanks Steve. For now I will build a conservative timing table with max 36-38 degrees.

 

I've been messing with my GM IAC I got from Protunerz. Managed to catapult the pintle into oblivion a few times. I didn't realize there is no stop. My max homing/closed/moving is at 160 steps. The IAC properly extends and stops at whatever CLT temperature is at. If I set the IAC at always on/hold current, it is making high pitched annoying noise. I will leave it at 'Moving' for now.

 

I attached a fused 12V supply to it without my car running. What I _couldn't do_  is to use the 'Idle Warmup Duty' and put the max 160 steps in the 60-80F range to make the IAC completely close. Not sure, if this is because the car is not operational?

[madkaw]

36-38 max at 100 KPA ? If so I would back that off to about 34 . No problem to be at 40 at light cruise 

[darom]

Replaced the MAP sensor, it is properly showing the kpas now.

 

I have a bad air leak around cylinder 1, protunerz intake didn't seal the gasket. I did install it following the torque specs and order. While running, the air leak was audibly noticeable. I removed the intake, and didn't see any warpage. Ordered a new gasket.

With GM IAC installed and in a closed position, the throttle body is making high pitched whistling noise. I guess the shape of the opening for the valve makes this bad harmonics issue.

I also noticed my fuel pressure was around 50 psi. Adjusted the FPR, it is around 40-43 psi now.