Megasquirt. Advise needed please:)

[Oheggem]

As i`ve had tons of trouble along the way i actually drove it for the first time in years today. It was horrible!

I got the car running full sequential on high idle but smooth. Touch of the pedal it was responsive and willing. But, i had an oil leak that took fire on the header from the chain box gasket/o-ring. Did a repair keeping the cam steady and replaced to same position. But after first startup the ms3pro gave me cam fault and lots of sync errors and would not start unless full throttle. So i thought i messed up the timing when i put it all together again. So, again, took it all apart for cam timing. Timed the cam (only left side) from around 0.98 lift to approx 0.72 ish. All went perfectly but, same problem with running and apparently no cam signal. So f@ck the cam sensor then. Turned off full sequential and changed to one wheel trigger only crank, and it started but ran like ****. Since then it sounds like it runs on 4 cylinders. No power at all and lean. Tried autotuning in TS but just barely get it moving. I was so dissapointed :cry:

I thought i was ok on idle but it sounds like it has 4 cylinders instead of 6 and it runs like a 10hp vw beetle. Absolutely no power at all and barely able to take off. Can this kind of behavior be related to timing? Sorry to be such a n00b btw :roll:

Got 43psi fuelpressure, seem to have spark and did nothing to anything other than relating to chain box.

I have the Clewett/Electromotive trigger wheel and a bit unsure to offset on angle tooth #1. I`ve set it to 60 degrees. This shouldn`t have changed anyway.

Setup:

3.3 on ms3pro standard 930 intake manifold and cams
bb IC, headers and K27 7006 turbo.
Electromotive/Clewett 60-2 trigger wheel, VR sensor, coils
Siemens 80lb injectors
Front 044 fuelpump running 43psi according to the gauge.

Could i have done something to upset the system by work at the back of engine when timing? I really don`t understand.

Some Screens :

[LSR911]

Always start with the basics. Since you had such a difficult time with cam timing I recommend checking compression first to make sure the engine is sound.

Lsr911

[jons911]

I would highly recommend checking your trigger offset with a timing light. When I tried setting the angle by eye, the changes from making fine adjustments didn't make any sense as checked by the timing light. Turned out I guessed right, but was putting the value in wrong because of the way the AEM Infinity expected to read the value (how it was using BTDC compared to trigger position). With the correct value in, I was able to fine tune with the timing light really quick. It went from refusing to start to firing right up.

Also, where did you get the timing for your ignition map? I'm not super experienced with timing for various setups, but it seems a bit aggressive below 2000 RPM. I don't know what load you are at for idle, but my engine idles between 50 and 60 kpa, which would be around 23 degrees of advance on your map. I originally started with around 12-14 (don't remember at this point) at idle, and it would run and idle fine, but was super touchy and had a tendency to die if you let out the clutch without any throttle. I walked the timing back, rechecked, and it got more and more stable. I'm now down to 8 degrees, with the next few cells lowered a bit for a smoother ramp in. I kept lowering it to 5 degrees, but I didn't see any changes and raised it back up. This is on twin plug, so you'll have to add a few degrees to compare.

[flightlead404]

I second jon's comments about making sure the trigger angle offset is correct. I'm using COPs so I made up a short pigtail by hacking off 8" off an old harness and shoving a screw into the end of the wire. I put it between the COP and the plug and able to put an inductive timing light on.

If you have a toothed wheel you should be able to count the teeth that have passed the sensor when at TDC to at least get close enough to start up.

Wrt to the ignition table, that's not going to idle well at all. You need the idle point to be in a sort of a valley so if the engine slows down it advances, speeding the engine, and getting back to target idle speed.

Are you single plug? I'll post mine tomorrow should get you started.

[Oheggem]

Ok thx. Yes, single plug. Engine ran beautifully before i timed the cam. Weird this happened just by doing the cam timing. I was using Autotune function in Tunerstudio before i timed the cam so all those timing numbers are from that. Might not work after i changed the timing. So strange it ran so nice, just high idle before i timed the cam.

I have a timing light so i`ll try to get that working. Guess i can mount it on all the plugleads to see if all of them ignite. Does sound like it`S just on 4 or something.

[Oheggem]

Originally Posted by smurfbus

Wasted spark and you talked about full seq?

Did you put your plug wires correctly? Easy to mix two and run ****ty.

I had it running full sequential wasted spark before i changed the chain box gasket. It ran very nice just a little high idle at 2000. But that was related to the ICV. I had it as on off but should be PWM. After i did the repair i got cam fault and no cam signal, no sync. So i turned off sequential and only one trigger wheel instead. I need to get the camsensor sorted eventually.


I`ll check that too. Did not think of that. Although i didn`t touch them until i timed the cam. This started just after i changed the chain box gasket/o-ring. But i will check.

[cabbi]

I have about 6 years running MS3X but I may be able to help.

1. As others said check compression first to make sure you didn't mess up the cam timing. Can't go any further until engine checks out mechanically. Did you recheck valve clearance?

You mentioned fire? I would recheck functionality of all sensors and continuity thru the harness back to the MS plug at the unit. Check for shorts between individual wires as well. Did you melt a wire or sensor somewhere? Check coils functioning. Did a ground wire melt off or dislodge?

2. Where is your cam sensor located? I would review that cam sensor installation again to make sure you didn't cut, pull, or melt a wire by accident or dislodge the sensor or bolt. Check gap again. You never know!

3. I also have the clewett 60-2 and my angle is at 64 checked with timing light.

4. If you're running COP or CNP, are they securely attached to the plugs? It can take a fair bit of pressure to get them to seat properly. You can use the testing area of TS to check each coil to make sure it's firing and in the correct sequence.

Regarding the timing map, Are you running the idle advance/correction option in tunerstudio, or running right off the timing map? I don't know the proper idle and timing for a 930 but it's not 2000rpm and 35deg if you idle at 40kpa. I would start at 900rpm and 10deg and work from there.

See if you can get a datalog while cranking to see if the crank / cam signals are coming thru. Or there's the diagnostics tab in TS - composite logger I think. Cam signal may be there but could be inverted somehow or triggering at the wrong time.

80lb Siemens injectors...I don't know your boost pressure but this sounds like a lot. Are they within the stable PW region at idle? This may play a role in your idle issues.

Hope this helps.

[Oheggem]

Thx for that extensive answer. I have a lot to check out tomorrow.

[jpilcher]

I had a similar experience trying to get the sequential cam sensor to work. Car ran like crap.
I remember trying all the various configurations for the Ignition /Wheel Decoder.
I had read somewhere adding 360 degrees to Tooth #1 Angle may help. Car fired up and ran great.
My initial crank angle was 55 + 360 = 415 BTDC. Follow the setup procedure in the manual to determine crank angle with a timing light. I would check all the sensors around the area where you had the fire.

[jpnovak]

Are you running 3 bar of boost? 400kPa is our top row on timing, AFR and fuel trim tables.

That's. UMM... a bit much.

Spend some time scaling your tables properly for the range you will actually run. And yes, you will likely need to adjust some of the fuel and timing values during the tuning process.

[flightlead404]

Here is the ignition table I ended up with after the dyno, hope this helps.

This is an '86 turbo with SC cams, K27/29, RarlyL8 headers and hooligan exhaust, Turbokraft long next intercooler, and FrankenCIS. I'm using Denso COPs with NKG BKR8EIX plugs in a wasted spark configuration.

Of course, none of this will be of any use until you're sure your crank ignition angle is set correctly.

[Oheggem]

Thanks a lot. Really! I`ve been drunk since this setback happened so hopefully tomorrow i will dig into it again.

i will document what i do so it can help others if needed. I am just a hobby car lover and it seams i have a hard time learning certain things. So appreciate all the help i get.

[Alan A]

Also check shielding and grounds. Some of these sensors (tps I’m looking at you) can be real finicky.

[flightlead404]

Originally Posted by Alan A

Also check shielding and grounds. Some of these sensors (tps I’m looking at you) can be real finicky.

I second this! Especially the grounding. Thoroughly ground everything, ground everything to one place to avoid current loop issues, make sure there's a REALLY solid ground to the engine block, and that is well grounded to battery negative. For shielded wires, you only want to ground ONE end of the shield (probably the end closest to the 'squirt) and minimize exposed wires where the shielding is stripped off.

Also I found that with a 60-2 wheel that I was over driving the VR sensor starting somewhere around 4k rpm (dig up my old threat on this). Make sure you're not doing that, I found an oscilloscope to be very useful. There are several approaches to dealing with this, but I ended up putting a VR conditioner inline.

Finally, if you've got RPM limiting enabled, double check the settings on that, and finally double check your overboost settings in the 'squirt. Remember they are ABSOLUTE not gauge. So your overboost should be at 2bar not 1 bar (I spent an entire day on this before the light came on duh!).

[xbmwguy]

Also I don’t believe you can be wasted spark And sequential together. Iirc one or the other. Also this is fast930 from the ms forum. Been super busy at work and will try to get you some baseline tunes from my older computer

[Oheggem]

Hey I just think it is strange that before i the first time i opened the left side up to change chain box gasket/oring to cam tower i had it set to full sequential and it had the smoothest idle. Throttle response was awesome. With wasted spark. Then after i did that repair i suddenly had cam fault on no sync and ran ****. That's when i thought i`d messed up the timing and went back in to time the came from 0.92 to 0.72 but no change. So i think something happened to the cam sensor or my tooth inside. So annoying!!

I went back to my initial setup but turned off full-sequential and got it running an ok idle but same as before sounding like 4-5 cylinders running. I was trying to find the correct degrees on tooth #1. Should i set timing fixed to 0 when i do and adjust until i get tdc on crank wheel to tdc? Found the timing light handy. Never used one before.

If i cant fix this i will have to just bite the lemon and buy the Clewett scavenge pump with cam signal and cops. It`s a big cost though so hoping to avoid it.

Wasn't able to do much as my 680 battery had enough. Its on charge now so bak at it tomorrow

[cabbi]

Originally Posted by Oheggem

So i think something happened to the cam sensor or my tooth inside. So annoying!!

This was my first thought. Are you getting anything in the logger in TS? If not you'll need to get in there to see why.

Originally Posted by Oheggem

Should i set timing fixed to 0 when i do and adjust until i get tdc on crank wheel to tdc? Found the timing light handy. Never used one before.

I paint a little white dot on the Z1 TDC mark on the pulley so it's easy to see with the timing light. Start TS and engine. Then set TS to Fixed timing to 10 degrees, crank angle to 60 to start, then set your timing light to 10 degrees and adjust crank angle up or down until you see the white dot line up at 10 degrees.

[smurfbus]

Try the TS - composite logger cabbi suggested before. I have alternating + full sync on my TS and if I have cam sensor failure it will switch to alternating squirt. I also have on wheel decoder 'one coil 'and 'tacho' out where you have wasted spark and spark. I use Trigger wheel arrangement = Dual wheel with missing tooth and falling edge for my VR and you can test which works better for you. I also have that 10kohm between VR black and white wires.

White dot was usefull for me too.

[jpilcher]

Try adding the 10 ohm resistor. It will help to stabilize the signal. One thing that helped me was to use a protractor to find the angle from the center of the VR sensor to the TDC on the crank pulley. The composite logger can be used to verify the angle.

[flightlead404]

Originally Posted by jpilcher

Try adding the 10 ohm resistor. It will help to stabilize the signal. One thing that helped me was to use a protractor to find the angle from the center of the VR sensor to the TDC on the crank pulley. The composite logger can be used to verify the angle.

I tried the protractor route it was a pain.

Simple math will tell you how many degrees for each tooth, and eyeballing the number of teeth will get you close enough to start the engine with, say, 10 BTDC fixed timing, then put a timing light on to adjust accurately.

I also tried a number of different resistor setups with my 60-2 toothed flywheel, none were really satisfactory at high RPM. I ended up using a VR conditioner from the Speeduino project inline, and worked well.