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Can't get engine to start

Posted: Tue Jul 06, 2010 4:01 pm
by noface
I have a 1994 Nissan truck KA24E engine I've installed into a 1985 Nissan 720 (originally carb'd).

I've built my MSII V3.0 to the specs here using the MSII to directly control the coil and trigger from the dizzy. Also using the stock Nissan PWM idle valve. This write-up:

http://www.DIYAutoTune.com/tech_article ... _240sx.htm

I bought the MSII kit from DIYAutoTune, plus their pre fabbed DB37 cable and relay board.

I'm using the latest MSII code. I think 2.89? from the website.

I've set the base paremaeters as outlined in the MS build Instructioins and install article.

The engine cranks, I can see all the gauges work in MegaTune, but it will roll over a couple times, and then kick back and/or stall the starter motor. I''ve moved the dizzy all around trying to find a spot where it will start. I've got to the point where sometimes it will fire a couple times, but just maybe on one or two cylinders will hit and sputter.

It seems if I use very short bursts on the starter works best, it'll sputter once or twice, but that's it.

I've connected an inductance timing light to the #1 cyl, and it seems to fire very erratic. I've also connected the timing light on the coil wire, where I'd expect to see a lot of strobe. I see a whole lot more than just being connected to the #1, but it still doesn't look like I'd expect it to. Erratic is about best I can describe.

I don't know my sensor values. SUch as injector properties, coolant tem, MAT temp, etch. I'm using the stock sensors. I've played with the offsets in MegaTune enough that I've now got the coolant temp to show about 70degF, but I still see no WUE on MegaTune when I try to start the engine...

Does anyone have any ideas on how I can get this thing to run, point me to a place where I can get the values to my sensors, or even a MAP/Ignition config that I can download to MS to get this to run?

I haven't got much hair left, and the Optima is even growing tired....

Thanks for any insight.

Regards,
J

Re: Can't get engine to start

Posted: Wed Jul 07, 2010 1:02 am
by trakkies
I'd be inclined to remove the dizzy and MS and set things up on the bench and make sure you're getting the dizzy to trigger MS reliably. It seems you're using an optical sensor which should trigger properly at very low speeds so easy to see it working, just by spinning the dizzy by hand. Once you're happy with this, setup the static timing by eye to about 10 BTDC. Then check with a timing light it is cranking at no more than 10 BTDC.

Re: Can't get engine to start

Posted: Thu Jul 08, 2010 12:17 pm
by noface
verified wiring again, and went over a couple of things in MegaTune.

Tired a different coil, and still same result.

Removed the oil pump and dist to verify timing, and it looks good. Removed valve cover and found that the timing marks are off by one tooth... so this is likely my problem.

I'll update when I get this corrected.

Thanks for the insight.

JS

Re: Can't get engine to start-IT RUNS!

Posted: Sun Jul 11, 2010 3:10 pm
by noface
but it's a b*tch to start

timing is off I'm sure.

It idles at 1800+, and I can't get it to idle any lower.

I still don't know my sensor values (all stock Nissan Truck KA24E 1994 model year). I just plugged in some numbers from some similar injector values I found on the internet. The coolant temp and IAT numbers don't change much, again, I just plugged in some numbers until I got readings that I thought would work. I need some help finding out the values.

How do I get the idle down to 800 - 1000?

Put a timing light on it, and I can't find the marks. Is there an offset in MegaTune that's jacking up my timing?

I think if I get these correct, it'll make it a WHOLE lot better. I'm a newb, so I need some help.

Thanks!
JS

Re: Can't get engine to start-IT RUNS!

Posted: Mon Jul 12, 2010 12:15 am
by trakkies
noface wrote:but it's a b*tch to start

timing is off I'm sure.

It idles at 1800+, and I can't get it to idle any lower.

I still don't know my sensor values (all stock Nissan Truck KA24E 1994 model year). I just plugged in some numbers from some similar injector values I found on the internet. The coolant temp and IAT numbers don't change much, again, I just plugged in some numbers until I got readings that I thought would work. I need some help finding out the values.

How do I get the idle down to 800 - 1000?

Put a timing light on it, and I can't find the marks. Is there an offset in MegaTune that's jacking up my timing?

I think if I get these correct, it'll make it a WHOLE lot better. I'm a newb, so I need some help.

Thanks!
JS
You need to calibrate the coolant and air temperature sensors correctly, if you can't find the data. Remove them, and with an accurate thermometer using a freezer and a pan of boiling water, measure the resistance at approx 0C, ambient and 100C and enter those values into 'calculate thermistor tables'. The coolant sensor has a big effect on the fuelling so must be correct.

Use this site to find your injector flow rates:-
http://users.erols.com/srweiss/tableifc.htm

Re: Can't get engine to start

Posted: Mon Jul 12, 2010 3:49 pm
by noface
I've measured the sensors at different temps and plugged the numbers in. All in all, it runs about the same.

Injector specs for my injectors are non-existent, at least I've been unsuccessful at finding them. I've got Hitachi injectors JS21-1 or 16600-86G10 (from Weiss website- but no data). Sent an email to Hitachi... we'll see if they respond.

So i plugged in the numbers here and used them for my megaTune setup.

http://www.gtsparkplugs.com/InjectorSizeCalc.html

In the dialog box when plugging in the injector numbers it asks for Air Fuel Ratio... what do I put in that field? I put in 14.7 for Stoic?

I'm really confused about how to go about setting the timing and offsets, setting, etc in MegaTune.

How do I make this appear in MegaTune? I can't for the life of me find the button or menu item... I'm a snake hunter baby!

Image

Re: Can't get engine to start

Posted: Mon Jul 12, 2010 6:39 pm
by Bernard Fife
nf,

It's here: http://www.megamanual.com/mt28.htm Look for "trigger wizard".

Lance.

Re: Can't get engine to start

Posted: Tue Jul 13, 2010 2:40 pm
by noface
Thanks!

I told you I was a snake hunter... I bet I been in that menu a hundred times looking, and it was right there.

Now... to make this thing run right... I'll keep plugging away at it!

Thanks again!

JS