Checked the plugs this morning and they are clean.

:D :D :D
I have just been for a drive around the block!

I still have a few problems to sort out, but I am back to having a car that starts and runs reasonably well.
The no-start issue seems to have been related ignition settings for Number of Coils. The only setting that seems to work now is "Wasted COP".
Also, although I checked a couple of the plugs previously and they looked OK (wet, but not drowned), it was only after I removed them all and thoroughly cleaned them that I managed to get enough sparking action to start the engine. Once it got going and warmed up, it ran fine.

The engine will not start with Number of Coils set to "Coil on plug" even though it ran for the past few years at this setting. :confused:

I have found and fixed a wiring problem with the Clewett cam sensor. The wiring diagram that came with the sensor was ambiguous but has been clarified on their current installation instructions. I now have a cam signal in the composite log, but it doesn't look like others I have seen. There is definitely something wrong with the signal because when I select sequential coil on plug, the engine doesn't fire at all.
I tried adding 360* to the Tooth #1 angle setting to make it 447* instead of 87* and it started but sounded like it was on three cylinders. :confused:
Changing back to "Wasted COP", the engine fires up straight away.

I still have a few things to figure out, but at least we are getting there.

Bill,

Glad to hear you got the engine running again even if it is wasted spark. The tooth composite log you posted a few posts back did not show the cam input. (By the way, the red lines at the bottom are sync losses.) If it did, there would be a green line at the top portion of the log and a single pulse would show up every two engine revolutions. Do you know if jumper JP7 is installed on the MS3X card? That needs to be there for a pull up when using a hall cam sensor. Also, the trim pots (R11 and R32) need to turned fully anticlockwise, then turn R11 three turns clockwise.

Bill,

Something to be aware of when running wasted cop. If you have 12vdc supply fused for the coils, you may blow the fuse at high RPM's because of the added current draw from firing the coils twice as many times. It happened to me when running wasted twin plug back when I was using MS2, blew a 15 amp fuse.

After rereading your post, I see you now have a cam input on the composite log. Can you post a picture of that now? Do you know approximately how far BDTC #1 cylinder the cam sensor should give a pulse? Also, what firmware version do you have installed?

I don't know the purpose of the render option, but the composite log looks like this with render set off and on.

http://forums.pelicanparts.com/uploa...1521509200.jpg

http://forums.pelicanparts.com/uploa...1521509213.jpg

As far as the position of the cam signal is concerned, I am not aware of any setting to change this. The sensor timing bolt was installed in the end of the cam as per Clewett's instructions and I rechecked it when I had the sensor out last week.
The cam signal seems to neatly straddle every second missing tooth event at the flywheel.

Last weekend I worked through all the pot settings as per the current MS manual and they are now set as you have described. I don't recall setting these when I installed the MS3X four years ago ... may have, just don't recall.

I don't know which firmware version I am running at present and can't connect right now to check. Last time I updated it was probably a year ago.

I have the coils running on two 15A fuses, one for LH side and one for RH side.
Initially I had them on two 10A fuses but managed to blow them one day in test mode when I set it up to run at 10,000rpm! If it dies at high speed, at least I'll know where to look first. :)

Bill,

I "think" MS would like the cam pulse to happen BTDC on Cylinder #1. Maybe try changing the cam setting from "Falling edge" to "Rising Edge" to get the cam signal generated BTDC and see if that will make a difference.

The reason I asked about the firmware is because later versions have an cam input option called "Polling" where MS looks for the cam signal at a specified engine angle BTDC. But I don't think you would need that because it looks like you have a nice cam signal, but I do think it needs to be BTDC. The latest version firmware is 1.5.1, which implements engine states that required some research, datalogs to determine some of the parameters and then fill in the data for the engine states.

Yes, Rising Edge would trigger the cam sensor right before the missing tooth for TDC.

Render ON shows the entire time the signal is present. Meaning, as the bolt passes the sensor it generates a box car shape. The actual trigger point is the short pulse shown with Render OFF. IF you change from falling edge to rising edge you will move to the other side of TDC - meaning trigger from the front of the box shown in Render ON mode.

Rushed home from work tonight, switched my edges, turned off wasted and who'd a thunk it! It just started up straight off and idled normally!!
Love you guys :D
Thanks heaps.

I haven't had a chance to go for a drive tonight (damn dinner guests), but I see a trip to work tomorrow in a Porsche instead of a VW.

Awesome news.

Bill, It has been a journey. I am very glad you got this issue sorted out. Now you can do some fine tuning and maybe get an IdleCV working.

Except 5 cylinder motors sound awesome :-)

Haven't heard one

Awesome news, Bill!!

It's always something easy.....

Started on that today. I ran Autotune on the 20 min drive to and from work today and pulled out lots of fuel in the middle and high load areas.
I had done this (Autotune) before when it was running in wasted spark but it seems that now that it is running in sequential, it needs less fuel.

I have two driveability issues to resolve.
I get quite severe surging at really light throttle between about 1000 and 1300 rpm.
When I stomp on the gas, I get a bit of a hesitation, otherwise it runs and idles fine.
Got any hints?

I am not yet sufficiently recovered mentally to tackle the IACV again. Fortunately, the weather is still warm and I don't really need it. :)

Light throttle surging is usually due to wrong advance settings. Also look to make sure you don't jump values in timing from idle to 1300 rpm.

If the AFR is rich then retard the timing. If the AFR is more lean you need to add timing. Its a balance. The datalog is your friend here.

for stomping on the pedal you need to look at the acceleration enrichment (AE). Needs a shot of fuel when you open the throttle. Turn OFF AE until your fuel VE Table is well mapped. Then add AE to fix the transitions.

Bill,

Over on the Megasquirt forums, member "whittlebeast" has a thread under the "Tuning" category that deals with AE tuning. Lots of good information there as well a link to YouTube videos that deal with setting AE up. Since you are running ITB's, AE will be based on 100% TPS.