420A motor first start fires but will not run

[Tired2]

So, I'm pretty new to this... I managed to get everything wired up and tested, sensors, spark, etc. I realized that I had a bad fuel injector, so I replaced them all with 560cc injectors. Trying to start the car now, it will ignite a few times, and then when the "cranking" light goes off on the gauges in TunerStudio, it dies.

My car is an eclipse with a 420a motor, 2.0L 4cyl running wasted spark with 2 MS2 internal BIP373 coil drivers.

The injectors are Low-Z (2.5 ohm), and I have my settings set up as stated in the manual for MS2 with Low Z:
Current Limit: 30%
PWM Time Threshold 1.0ms
Dead Time 0.6ms.

Req_Fuel is at around 6ms, but when I convert the injectors over to the base fuel pressure I'm running (60psi), I get 660cc, or 4 ms Req_Fuel. I tried both values with no luck.

Also, I'm running the "suggested base tune" from Symtech Labs, but I have not really messed with the fuel or spark tables, and to be honest I don't really know where to start changing them yet. The car is turbo, hence the injector size.

Worth mentioning also, is that I neglected to check my base timing, my timing gun failed me, and I have yet to get a new one. Could that be a problem? It ran on the stock ECU okay prior to MS, so it should be close, right?

Does anyone have any ideas that could help me out? I know I have fuel pressure, and I know I'm getting spark. Can someone look over my MSQ and a cranking log and help me find out what is going on? Thanks.

[rickb794]

Did you calibrate your sensors?

In the TS tools menu.

[Tired2]

Yes...

CLT and IAT are GM Sensors, which I believe are stock calibration on MS.. They read close to ambient temp when the car has been off, so I think they are good.

I calibrated TPS as well, and selected my WBo2 sensor (though I have ego feedback disabled I'm pretty sure). MAP is stock MS unit and reads near 100kpa when the engine is off. Crank sensor sync has not really had any problems either.

[The Deviant]

Worth mentioning also, is that I neglected to check my base timing, my timing gun failed me, and I have yet to get a new one. Could that be a problem? It ran on the stock ECU okay prior to MS, so it should be close, right?

Why does everyone think this is optional

Having confirmed that the coils work as expected and with the fuel pump still disconnected, hook up a timing light/strobe to plug lead #1. Yes this is really needed - correct timing is very important.

Seriously- this is not optional. It *could* be close... ...or maybe not. It would be a complete guess unless you check it with a light.

Running through a pre-start check list is a good idea, and helps make everything EASY.

I know the "first start" manual is under MS3, but it's a good 'step-by-step' for EVERY install. http://www.msextra.com/doc/ms3/firststart.html

[duxthe1]

DO check it. It bit me in the ass on my initial install. I had a buddy strobe it while I fiddled on the laptop to set the offset. Well he found 10 ATDC instead of 10 BTDC. Needless to say I was struggling big time trying to get it up and running right with the timing 20 degrees late. I wasn't until I locked it at 0, 10, and 20, and then strobed it did I realize what was goofed.

[Tired2]

Thanks, I'll get a new gun and give it a go.

I have a very bad habit of always learning things the hard way

I'll report back what my timing is, hopefully it will go well.

[rickb794]

I'm not sure the Neon-420 code needs to be adjusted since it is crank triggered and not moveable.
Worth checking to verify though.
Spark does increase (not much but it is not dumping).

In the log I see fuel spiking as the rpm decreases and the tp increases.
I'm thinking it is either getting too much fuel or not enough.

I'm leaning towards too much fuel because as the map comes down (vacuum comes up) fuel is not increasing (significantly) and rpm is.
then you open the throttle and AE pours in fuel and the motor dies.

It's difficult to analyze without standing next to it and hearing what it does.

Can you increase the throttle plate angle at closed some and try to start it without opening the throttle? I think it just needs more air to start.
As you started to open the throttle the RPM picked some until AE kicked in and flooded it. SWAG!

What are you doing for Idle speed control? 4 wire IAC? Increase starting steps.....? Or just temporarily turn up throttle closed setting.

[Tired2]

Interesting, thanks for taking a further look.

My natural instinct is to feather the throttle a bit, but I definitely think something goes wacky when it switches out of cranking.

I am using a 4 wire stepper based IAC, it is hooked up, but I have yet to verify it is actually working, I should probably test it out as well. I had it disabled in the code for the start that I attached the log for.

Unfortunately my car has no throttle body blade stop adjustment, so maybe getting the IAC functional is more important than I initially thought.

[rickb794]

Not familiar with the Mitsu throttle body but it has to have some kind of stop the keep the blade from sticking.
Shim it open some from closed, maybe just pull off the power brake hose to raise the idle speed.
There may be a hidden screw you can uncover to adjust the throttle plate angle stop.

Tuning the ISC without the motor running decently will be difficult, as changes to the throttle angle will cause other features to confuse things.
I usually start with a fixed idle and get the fuel and spark tuned very well in the idle area before turning on the ISC.

[Tired2]

Here is a shot with the TB in it:
https://picasaweb.google.com/lh/photo/i ... directlink

The spot where there is typically an adjustment screw, it is filled in with metal... I think they just do that to keep people trying to adjust it since it uses IAC/ISC. Also note that this is the Chrysler 420a engine in a mitsu car, its the bottom of the line car (RS), all the others (GS, GS-T, GSX) use the 4g63/4g64 Mitsu engines. The 420a is used in lots of cars, including the Neon.

[rickb794]

That throttle stop is adjustable, there is a cover over the screw.
Punch or drill a hole in the cover and use a screw to pull the cover off so you can adjust Idle.
Once you get the IAC working you can retrun the throttle stop to the the factory setting (which should be just short of closed).
It is set that way as PCV gack will eventually close a partially open throttle gap. So just short of closed to prevent sticking is the correct setting once the IAC is functional.

Just to clarify, I believe Chrysler liscened the motor design to Mitsu.

OH here it is, in the Neon FAQ

Is the Neon's engine really a Mitsubishi product in disguise?
- No! This is a persistent myth, particularly among DSM owners, founded on the history of cooperation between Chrysler and Mitsubishi.
In fact, the naturally aspirated Eclipse 2.0 litre is based on the Neon engine, which was entirely developed by Chrysler.
However, the head is reversed in the Eclipse installation, with the exhaust manifold facing front.
The Mitsubishi turbo engines, on the other hand, were designed in Japan and do not have any common parts with the Chrysler product.
The 420 is a Mitsu and Neon motor is a Mopar

[Tired2]

Hey, just an update, and marking this 'solved'...

Thanks for all the help and suggestions. I got a timing gun that worked, and checked my base timing... looks dead on.

After playing with it for 20 minutes or so, I finally tried everything and was reading the startup guide again, and realized I had set my PWM current limiting at 30%, instead of 70% for my Low Z Injectors. I think it would kick on using fuel from the priming pulse, and whatever else it could get, and then starve for fuel due to the injectors not opening enough.

Now I just need to tune them in and work on tuning the idle and such. It runs just fine, but I could not really play much tonight. I'm excited. Thanks!