Can someone please tell me why my idle is pretty rubbish. It is not a strong idle, and it is easily upset. Sometimes it just dies when it feels like or also when you come off the throttle quickly. My dashpot on my TII manifold is stuffed btw.

Here is the map

Running HR10f which is the lastest 029y5 derivative of msns-extra

What AFRs or PW do you guys use at idle? What timing? What split.


Please help i really want to get this car bacak to being the state of my daily driver!


Thanks for any help!

 

Note that the idle advance setting is deliberately set to threshold at 800rpm because the idle is at 1000, so its running off the table.

 

I run between -5 and 0 degrees timing, and between 12:1 and 13:1 AFR on idle.

Idles very smooth that way. However, my engine is bone-stock aside from the MS itself... you may need to vary things significantly if you've modified the engine.

Ken

 

0BTDC timing was great when msns was just doing spark, I wonder if I have rpm noise on my cas causing fueling fluctuations which is what is upsetting the idle.

 

Do you have a restrictor in your MAP line?

Ken

 

Nope

I do have a spare fuel filter

 

The stock MAP line I believe comes with a restrictor in the MAP line. I tee'd that line to my line to the MS so I could use that. So far it has worked better than any other restrictor I've tried on the rx7.

Ken

 

I made one, it consists of a Z14 fuel filter, and 5/16 fuel hose to meet the map line. Both joins are very close to being crimped shut. This has really settled down the map sensor reading, and I nearly have the car idling clean.

I think I need a new dashpot because mine is flogged out and the throttle can snap shut when you clutch in and brake.

 

Which port on the T2 manifold are you using for the map signal ?

 

When you showed me your datalogs.
They are too rough. it should be smooth(you already know this).

Convert to Normal CAS and put extra shielding on the cable.

 

There's not really any need to do that unless he's got noise on the CAS signal... and even then converting to a normal CAS wouldn't help... and shielding only *might* help. I've found that the CAS signal is a lot more sensitive to having good grounds and a relatively clean +12v going into the MS.

I've run on unshielded speaker wire but with the MS grounded well, and the ground from the engine to the battery cleaned up, and a clean +12v with literally no noise problems. I don't recommend doing that (I was doing it as a test) but it did work.

Ken

 

i moved my map line to just behind the TB, the stock location was just on one runner and was realy bouncy... but how do you guys get your cars to idel at 0 deg timing, mine floodes out and dies, i'm running like 30deg... i also have a 1/3BP on a high comp 6 port motor.

 

Odd porting can make it necessary to run different timing. I'm running a basically stock engine, so it runs great at -5.

Have you verified your timing with a light though to make sure the actual timing matches what the MS thinks it's setting the timing to? You could just have 30 in the MS software, but actual timing of a lot less (if you're 1 tooth off, you can be about 30 degrees off or more).

Ken

 

I do have rpm noise. I've been discussing this with rx72c a fair bit.

I have taken the plunge and ordered a 60-2 3.5" crank wheel.

I figure I will use

1
11
31
41

As trigger settings and enter 60, and -2 teeth. And it will be merry.

I will be buying a honeywell hall effect sensor once I have the crank wheel here.



And if its not thing I'm betting its all of those beather ports near the injectors that I just blocked off. Work will be slowing down as I'm in an industry placement through my uni ata, and my lc-1 is in rma atm as its toast for some unknown reason.

 

hrmm, 60-2 won't help noise, fixing grounds and power will.

Ken

 

They are already fixed. I put in the hudge ground strap and the independant power.

On another bad note, I think I burnt something on my 3.0 board. I shorted out an unfused wire straight from the battery last week onto something on the megasquirt after I took it off the road again and now my megasquirt doesn't power up.

Also I have a fuel leak, ARRGGG

 

That doesn't necessarily fix the grounds. You also have to make sure you ground to the correct place(s), and avoid creating ground loops. I frequently recommend sticking with the stock ground locations, and just cleaning those up, replacing cables only if necessary.

Ken

 

My install is "solid" and the grounding is simple: Everything ECU related, *everything*, grounds to the same bolt on the engine. Including the sensor grounds. Floating grounds simply cannot happen when you do that.

 

Everything critcal is earthed straight to the battery. The only things I've wired in that use the chassi earth are the Coils and the Fuel pumps. Everything else I've added has its own wire straight to battery -ve.

The ms failure problem is more important now tho. Its not powering up at all


Well theres 5V coming out of the voltage regulator. But theres not 5V at the cpu socket.
The F1 polyfuse is very hot

 

5V on the in side of F1, 0V on the other side. So the short to ground is after that. But no idea what or where.

 

If the polyfuse is hot, it might be the fuse itself that's busted... Check your polarized caps and check your diodes as well... all in the power circuit of course.

Ken

 

Thanks Ken, I will have a look. I'm going to step over to ms2 when i get this fixed.

I'm definetly going hall tho, i just hope the active sensor removes some noise problems

 

yeah, 60-2 by itself wouldn't help a bit... but if you're going to a hall sensor, most likely your problems will disappear.

Ken

 

the wheel i'm getting has 60 teeth over ~11-12 inches, so they are close, and the hall sensor is quite big. Is this gonna be a problem?

 

I just removed C1, C22 and C23 and they aren't shorts and also didn't fix the problem.

This leaves many other things. But I don't think it can be the LEDs and it also can't be the LED transistors because they all have series resistors.

I will try and get a new MAX232 from uni tomorrow. Might even have one laying around here.


That leaves. The 5.6v zener being used as a crowbar. Which is a likely suspect. C3 which I can't get to because of the map sensor, and not too many others.