Author Topic: Almost no spark, Nissan SR20 initial set-up.  (Read 20573 times)

Offline BenFenner

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Almost no spark, Nissan SR20 initial set-up.
« on: September 29, 2007, 09:30:53 am »
Okay, I've spent most of the day getting VEMS and sensors configured. I'm really on the final stretch. All of my sensors are working and calibrated. I am at the ignition timing step. When I crank the car to begin timing, the rpms display 180-210 and very occasionally I'll get the timing light to strobe, but not very often, and not very consistently. I've triple checked my wiring and everything seems to be in order. Any thoughts?

This is a single coil, wasted spark with distributor set-up.

My current ignition settings are:

Ignition outputs in use in h[2]      00 only
Ignition driver type                    DUMMY
Invert driver output                   Disabled
Dual Output Mode                     Disabled

Coil chargetime @14V (ms)         1.98
Coil chargetime added @6V (ms)  1.51



Changing the dwell times blindly doesn't seem to help much.
« Last Edit: September 29, 2007, 09:40:13 am by BenFenner »
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline rob@vems.co.uk

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #1 on: September 29, 2007, 02:19:56 pm »
Start with a charge time of about 4mS @ 14v for the single coil.
Have you set up the ignition outputs to only fire the coil channel?

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #2 on: September 29, 2007, 08:00:50 pm »
Yes, I have things set up to only fire the single coil. I'm not sure of the settings right now as I'm not working on the car, but I do believe I have that set-up correctly. I'm gunna take a shower and head out for another day of tinkering. Wish me luck.
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #3 on: September 30, 2007, 12:23:22 am »
I couldn't figure anything out, so I took the old coil from my old setup and plugged VEMS into it. I then ran a single spark plug wire from the coil to cylinder 1. This produces consistent spark, but it seems VERY slow at 1 spark per second at about 180 rpms. Shouldn't it be more like 12 sparks per second? 4 sparks per revolution with 3 revolutions per second.
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #4 on: September 30, 2007, 01:12:04 am »
I'm still sitting here with about 1/12 the sparks I should be seeing. I notice that when I disable the secondary trigger, I don't get an rpm signal anymore. This seems odd. I've tried switching the primary and secondary trigger wires with both enabled and that prevents rpm reading as well. Still stumped.

I'm just gunna wait until I get some more advice. I'm all out of ideas.
« Last Edit: September 30, 2007, 04:51:07 am by BenFenner »
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline rob@vems.co.uk

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #5 on: September 30, 2007, 05:43:00 pm »
First lets check the Settings->Ignition Settings screen.
Ignition outputs in use h[2] should be set to 00 only
Ignition driver type is DUMMY

Now in Settings->Ignition Outputs you need to set 0 to the Pin that you've connected the coil to.

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #6 on: September 30, 2007, 06:26:24 pm »
Yep, those setting are correct. EC36-pin35 is the one I'm using, and all of the rest of the settings match. Next?
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline rob@vems.co.uk

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #7 on: September 30, 2007, 07:25:01 pm »
3 revs per second two firing cycles a revolution.
Also at a low speed you might be on the verge of a synchronisation issue, can you pull the spark plugs and retry?

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #8 on: September 30, 2007, 07:44:55 pm »
3 revolutions per second, sure. But shouldn't I be seeing 4 spark events per revolution? One corresponding to each cylinder? Remember, I have the coil connected directly to spark plug wire 1, taking the cap/rotor out of the equation. My timing light will show me every spark event.

Pull the plugs? You want me to put the cap/rotor into the mix, pull my plugs, crank the engine and watch the plugs for firing?

If that's what you mean, I'll go do that and note the firing frequency and order.

I'd like to get this figured out within the next 9 hours or so, so if you could check back here frequently until you pack it in for the night, I'd greatly appreciate it. =]
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline rob@vems.co.uk

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #9 on: September 30, 2007, 08:41:19 pm »
Its a four stroke so that means two revs per cylinder for each firing event.

Pulling the plugs and addition of a seperate battery (if possible) will get that cranking speed up, ground the plug that you have the HT lead connected to, and you should see the RPM speed well past 300rpm, with a good spark.  Concentrate on getting the timing set to the cranking advance specified in Priming Cranking and afterstart, as long as the timing mark stays constant (on every other ignition flash) then you can consider the trigger to be okay.

Once you've adjusted the TDC after trigger value to get the cranking advance correct for the set value, you can then introduce the distributor into the mix.

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #10 on: September 30, 2007, 08:58:29 pm »
It's a coil and distributor set-up, wasted spark right? So one revolution per cylinder for each firing event?

I see, you wanted me to pull the plugs so the engine can crank faster and easier. Done.

I've taken videos of the spark plugs while cranking. When I crank the car using the cap/rotor set-up I get very inconsistent spark (plug 2 only I think) and very slow. Once every 4 seconds or so.

When I crank the engine with plug 1 hooked directly to the coil, I get consistent spark on plug 1, but it is still pretty slow at 1 spark every 2 seconds.

You're saying I'll be able to set the timing with plug 1 connected directly to the coil? Even if it's flashing so slow? I'll go give it a shot, but I'm not hopeful.
« Last Edit: September 30, 2007, 09:16:07 pm by BenFenner »
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline rob@vems.co.uk

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #11 on: September 30, 2007, 09:30:40 pm »
Its not wasted spark, and will fire once per trigger event (every 6 teeth with disk running at 1/2 engine speed)

With the distributor cap we may be having issues with where the rotor is when the ECU decides to fire, so you may need to mess with the trigger tooth and swing the distributor around to get the timing closer...

If you can do me an MSQ file (File->Save As...) I'll see if there is anything that seems to be out of place, there shouldnt be though...

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #12 on: September 30, 2007, 09:49:19 pm »
Not wasted spark? I've been assuming that this whole time. Damnit.

I'm uploading a video of the timing light pointed at my crank pulley. I'll have that link soon.

How should I send my MSQ file? E-mail?
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)

Offline rob@vems.co.uk

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #13 on: September 30, 2007, 10:36:00 pm »
With the cam mounted 24+1 trigger we're sequential ;D
Email is fine.

We're trying to shift this forum to another server because this one has become too slow, so if you have problems uploading or contacting the server then you might have to wait until tomorrow.

Offline BenFenner

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Re: Almost no spark, Nissan SR20 initial set-up.
« Reply #14 on: October 01, 2007, 12:21:49 am »
I've been trying to get the timing to 0 degrees using the single coil connected to plug 1. I couldn't see any timing marks on my crank pulley even while turning the distributor. I flipped the CAS disc, and now with my distributor at full advanced, and Crank Advance (deg) set to 63.75 (full advance) I can finally see the timing marks on the pulley. They are close, but off by a bit. Nothing I've done can get them any closer. I need to advance timing more I think, but don't know how.

As a side note, I see the markings every timing light flash, not every other as you said would happen.

Any new ideas?
1994 Black SE-R (VEMS, going turbo)
1994 Black SE-R (with sunroof)