Hi everyone!

I'm having trouble with my MS 1 v3.0 installation.

The setup is as follows:
'88 RX-7 GTU with a street port
new hi-imp 460cc injectors
new TRE Performance 255 lph fuel pump
Stock CAS (no missing teeth)
i also have a relay board with the MS (don't know if it matters that much)

It was a real trouble to get it idle, so we have to tune idle at ~1000 RPM (although when we plug the stoch ECU back the idle is pretty good ~750 RPM)

The engine is hard to start and revving very lazy.

Could someone review the .MSQ and DATALOG to see if there's anythings is obviously wrong?

Many thanks in advance!

 

Sounds like the timing is off or AFR is off.

For timing it might not be caused by anything in the settings, but the CAS position instead.

I'll look at the settings when I get a chance though.

Ken

 

If the CAS itselft would be way off, it would work like crap with stock ECU as well, right? So most probably it's the MS settings.

 

Ken, please note a weird thing on the log: when i depress accelerator slightly MAP raises as well as pulsewidth, but AFR drops for a moment! This looks very odd to me and i can't find explanation so far...

 

You need to set the CAS after the 'Squirt is installed. In the Spark Settings, set the timing to a fixed -5 and then line the CAS up with the leading mark on the pulley.

The lean spike is caused by not enough accelerator pump.

 

Aaron is correct which is why I was suggesting that you check your timing.

If you're using the stock CAS stab, you'll want wheel decoder settings of 11,1,5,7 with a 65 degree trigger angle.

Ken

 

Thanks, guys!

I will try to re-set the CAS and will get back to you!

 

Today i've re-settled the CAS with a strob light and shortened initial set coupler on stock ECU (it has been way too advanced by the marks, like 35-40 deg), but car started running like **** and now has probably half the power...

What could be wrong? I remember reading Kevin Landers' post that not all pulleys has the same marks on them and there's a chance that during the rebuild different pulley was installed... Maybe that's the case?

 

Why is the stock ECU even involved here?

You need to stab the CAS and time it to the Megasquirt. Trying to set it with the stock ECU won't help. Then verify your timing with a light.

If in doubt about the pulley, find TDC.

 

We've made the MS installation reversible with stock ECU in minutes, so I've reinstalled the stock ECU to get to the workshop with strob light.

I've been thinking that the stock mark 5 deg ATDC postion would be the same with the MS, given the 11-1-5-7 wheel decoder settings with 65 deg trigger angle. Will try to check the CAS position with strobe on the MS anytime soon.

Anyway with this CAS position i've been able to start the on MS and get it idle pretty stable on 800 RPM with 46-47 KPa of MAP, i guess this is more or less ok MAP for idle, right? We've even been able to make several test runs logging everything, so most probable the problem was the CAS in wrong position.

 

I run a 86 RX7 Race Car 13B street port. I use the stock 460 on the primaries and 700 on the secondaries. Secondaries cut in at 3800 RPM. Stock ignition system, ported intake runners, stock throttle body, header to 3” exhaust system. As you can see nothing special. Stock rotors and seals, and bearings. Up graded oil pump to turbo and increase pressure to 95 PSI at 3500 and up. V3 board MS 1 but I went with the missing tooth idea.

In my first race season I ran the MS system that was wired in parallel with the stock CPU as a back up. The next year I had the confidence to drop the stock system. I rewired the car so that I can remove the motor and MS system with weather tight connectors. I also have a back up MS box on the side burned and ready to go if I need it at the track.

I looked at your data log and see four thing that are stand outs with me (Note I am not a expert just tuning my car on my own for 2-3years at the track and shop).

Your MAP at idle is the same as mine. I would say you have no vacuum leaks and your good. Mine floats a bit due to a small play in throttle bushings. I don,t care I only need it to perform from 4500 to 8600 RPM.

1- Your idle AFR are at 14.5 and up mine is set at 12.8 to 13. (Adjust AFR in program add fuel.) Also on top of your throttle body there it a screw that you can turn. I found a quarter turn can make a good difference.
2- Your AFR with throttle applied is way to rich 10s this will make it miss and kill throttle response.. (Use the tuning program and adjust with the key board as you operate it). With no load 13.8 is wear I like to be. You will find your throttle will sharpen up.
3- AFR under full load from 3000 RPM to 12000 RPM (12A race engine not mine) 13.2 to 13.4 NO MORE AND NO LESS.
4- Spark setting THIS IS MOST INPORTANT BE CAREFULL. (BROKEN APEX SEALS!!!!!!!)
Never under full load exceed total advance of 26 Deg. Thank fully you are rich in most areas this would save your seals. You also want all your advance in by 5000-5500 RPM. (Look at my attachment).

Don,t rush setting the VE table it is the most important thing you do to set thing up I know. Then you can set the warm up stuff and accelerator settings. Note as you drive pay attention to the AFR on your data on mainly TP applications and map increasing. If you have a small spike or drop in AFR on the throttle segment tune before and after. Than look at the table and estimate what should be in the spike or drop ed zone. Then go to the throttle wizard and adjust out.

After each of my rebuilds I reset my AFR table up 6 point across the board to in sure when I go through the RPM range I don,t hurt any thing. I must do this because all I can do is data log and adjust after each season at the track. I can,t push the key board buttons and drive at 140 MPH at the same time.

My recommendation of AFR and Spark is based on at the race track knowledge road racing 30 min heats and 8 hour endurance runs. I also have a friend here that been working on race engines for Mazda for I think35- 40 years now. He was the first here to race with the first two rotor and has built three and four rotor engines. He is quite impressed with what I have done with this Mega Squirt equipment.
I hope this helps as far as the setting go in your program, wheel decoder stuff I will leave that to other that know more on that. In that area I set mine by what the rocket scientist on this site told me and did not touch it after wards. And I still have a few mistakes I,m sure.
Best Regards RX7 Racer Good Luck

 

I would not drive the car until you can set a fixed angle of -5 in the MS, and have the timing line up correctly with a timing light.

Ken

 

Thanks for your input guys! I really appreciate it!

I've had a couple of hours of test runs today and have a new log and map, could you please take a brief look at it? I have a hesitation at ~3600-3800 RPM and no matter what i do - advance/retard or richen/leaning it keeps hesitating, but past 4000 RPM up to around 5500 RPM it is quite nice already!

I'm starting to think that i'm turning on staged injection too early.

Thanks in advance!

 

I can tell from your data log compared to your last one you car idles better. Has better throttle response and is better between fast shifts. I know I have been there. Your fuel map is very close to mine in a lot of areas. No shock there since our porting would be close. A few things that I saw on your log and fuel map.

1- I did not see any major jump in your AFR or PW on change over to the second stage. (Based on what you have it looks OK your not running out of primary flow before the secondary come in.) But if you feel a slow spot or stumble I might say in this area you are way to low on advance. In some spot you have 5 to 7 degrees. I run under load at 3500 RPM 20 Degrees no problem and no dead spot.

2- I see that your AFR is very good now last data log was way rich 10 to 12.8. Your Idle is very good but in some areas under medium to full load your a little high. 13.6 to 14. Take and add in a couple of points to those areas(It looks real good compared to before).

3- I can all most bet you will be running 12.5 from 6000 rpm to 8500 rpm based on what I see on your map. Do not change the map, data log first, check then knock them down in sets of 5 to 10 to start.(Note I'm basing this on my own race car I do run 700 cc injectors on the secondaries not the stock 460. I do have 460 on the primaries. I all so at most tracks run in the 4500 to 8500 RPM range.)

4- A reminder At this point in time ignore the spikes and valleys on when apply the throttle. Work on stead state throttle and full throttle spots. Later get those spots out with the throttle wizard.

5- Do not exceed 26 degrees in total advance. Also check with a timing light before you go out and pulling hard high RPM shifts that your safe. Have a person rev it up slowly to 4500 RPM and make sure that the motor is 100% not pass the 26 mark on your crank pulley. Also never stab the throttle with no load on the engine the small stationary gears crack on the back lash of the heavy mass of 9 plus pound rotors. You will never see at a race track a rotary engine snap off at a idle. We all know your just ******* up the stationary gears. So I laugh at those guys on U-tube each time I see them revving the **** out of them.

I feel by what I see you cant hurt it keep up the tuning.

SCCA RX7 RACER

 

Thanks for all your comments mate!

But during the CAS re-setting i've noticed that most probably my leading coil is failing. So i will investigate it more closely and will get back to you.