Hey guys,

I'm using a MS1 V3 board that I assembled with the missing tooth CAS on a (what I believe to be) S4 13BT engine. Its in my 84 FB. The car cranks at about 300 rpm and sounds like its about to catch at any second but just wont. I'm running the extra code, and using the FC ignition components.

I've got 550cc injectors in both rails, FMIC, stripped emissions, freeflow exhaust, ported wastegate, Walbro 255 external pump with a surge tank setup, adjustable FPR, disabled OMP running premix.

I've got shielded CAS wires running back to the MS, and the adjustable pots are entirely counterclockwise as well on the board. I've got the pullup resistors wired to the LEDs for ignition, and have changed the resistor value for the air temp sensor and have updated the values using easytherm.

I'm also getting spark on both Leading plugs while cranking, (trigger angle of 60 with the 1,3-7,9 settings) but nothing on the trailing, though that shouldn't matter to get it started. I've also got 41 psi fuel pressure.

Here is my latest MSQ, ANY help will be appreciated.

Thanks in advance

 

Sounds familiar! I run a S5 turbo setup on an S4 6-port motor in my 79 SA. Makes for a very entertaining ride!

Verify your timing while cranking with a timing light. Once you are confident the MegaTune numbers match what's actually happening, you can put the timing light away.

Sounds nearly identical to what I ran earlier but I still have a functioning OMP. I've since gone to 720 secondaries, a Bosch in-tank pump arrangement, and have tossed the surge tank aside. The in-tank setup greatly simplifies the plumbing, and reduces noise as well. If you have the time, it's a worthwhile mod IMO.

You've done your research. Great job! Sounds like you have a decent tach signal, so the first hurdle is past. One issue to watch for is the polarity of the VR sensor, and associated VR input jumper on the V3.0 board. Be sure you have TSel connected to VROutInv, and NOT TSel to VROut.

Leading only operation is normal at low rpm, as the MS1 code doesn't support trailing below at idle speed and below. It should start and idle fine on leading only.

At first glance the basic settings look fine, certainly adequate to get you started. Are you getting fuel to the plugs? Are the injectors firing?

Where are you located? If you are in Waterloo, I could stop by at some point and give you a hand.

 

Hey, thanks for the quick reply

I believe the injectors are firing as the plugs are mildly wet when I pull them. Also, I do have the jumper on VRoutINV as I saw in another thread. Is there a way to verify the injectors are firing?

Also I've got timing dead on the leading mark while cranking.

I'm also currently in Mississauga, I'll be in Waterloo next week onwards. But the car will stay in Mississauga until I can get it driveable to take to Waterloo. Thanks for the offer Renns.

Any other advice?

 

You might be flooding the engine... I inject a lot less fuel on crank than you are right now.

Also, are you running a BAC valve? If so, you have it completely shut during cranking.

Trailing ignition doesn't come on until 800 rpms, so it's ok that it's not firing.

If it's close to starting but just won't quite get there... try pushing the gas pedal a bit while cranking... If the BAC valve is completely closed, you're not getting much air into the engine on crank, which I've seen cause hard starting.

 

Hey,

I don't have a BAC valve on there. And yea, it does seem when I romp on the pedal a bit it seems its about to catch. I tried using some starting fluid, and with that the engine will run about 5-6 revolutions at about 600 rpm before dying.

I've also confirmed the injectors are firings when I deflooded it once, plenty of fuel came out.

Muy, I'll try reducing the fuel tomorrow. What should pulsewidths be while cranking? The screen shows about 5.9 ms on the gauge when cranking. I don't have anything to compare it to, but this seems a bit low?

And to Renns, if you are up for it- I would gladly pay your gas and buy you a meal if you are willing to come down. I know it may be a bit of a trek for you though depending on where you are.

The battery will be fully charged tomorrow, and I'll try again. I also want to add, I'm getting pretty good compression. Nice strong pulses spinning the engine with the starter while the plugs are out. Its ready to catch...just a matter of time now.

 

If it fires with starting fluid, but not by normal cranking, that sounds like you are not getting enough fuel. Do you have primaries and secondaries reversed? Does your fuel pump run while cranking?

Has this engine run recently? If it's not sealing well due to fresh rebuild or old age, you may need to pull-start it to get it running the first couple times, similar to Terrh.

 

That's odd, the lowest the cranking pulse-widths go in your cranking table is 6.0 ms... so if it's at 5.9, it seems that your coolant temperature sensor is reading a temperature that's VERY far off...

I would also change the cranking speed to 400, just to be sure that while cranking, the MS isn't switching to the fuel table from the cranking pulse-width.

I wouldn't mess with the cranking pulse-widths until you figure out why your cold engine is using the hot-crank pulse-width.

Did you use easytherm to adjust for the coolant and air temperature sensors that are on that engine?

 

I'm at work right now, but I will check to make sure the primaries and secondaries aren't reversed. The fuel pump is definately on while cranking, I can hear it pumping and my friend confirms the FPR gauge is definately registering a good reading.

I do not know when the engine was run last, its a J-spec I picked up a couple months back. So perhaps a pull start may be needed...

I used easytherm, loaded the new file on the MS, and copied the .INC files to the car1 and the main folder, the readings changed from what they were before, so I assumed it was reading fine, and the sensors seem to be functioning fine. The air temp sensor wire came off for a little while, and that was registering funny. But the cranking pulse width is associated to the CLT sensor which was reading ~ 79F when I started, and about ~97F when I gave up to recharge the battery.

I'll recheck the injector wiring, the sensors, and the settings when I get back home to figure out why its using the wrong pulsewidths. I really hope I can get it started today.

 

OK, if you used easytherm correctly, but are still not getting the proper cranking pulse-width, then your cranking rpm is set too low and the MS is using the value from the VE table, or the easytherm changes did not succeed in the firmware, and the MS is using the wrong bin for fuel.

Either way it's using the warmed-up value for cranking pulse-width, which could cause a problem.

I'm sure it could also be what renns said.

 

Hmm.. alright- I'll try redoing the easytherm files and settings. Hopefully that fixes the pulsewidth problem. I'll also check the other stuff mentioned and report back when I can! Only a couple more hours at work...

Also wanted to say thanks, I appreciate you guys offering advice and looking over my MSQ.

 

Okay... I got home kind of late and didn't get a chance to try anything in the garage. But, I think I did figure out why the MS is using weird values for the cranking pulsewidths.

I measured the resistance of R4 and it came out as 9.1K.... The colour code is Yellow/Violet/Orange/Gold which is supposed to be 47K.

And R7 is supposed to be 2.49k? Because thats registering in at 792 Ohms...

I should have measured before I installed it. I will change that tonight, and try again tomorrow. Makes me wonder what other values are incorrect on the board. I'm going to go through the whole thing again tonight and change those two resistors.


I also checked the injector wiring, and I do have the primary and secondary injectors wired up to the correct pins on the MS.

 

When you measured the resistance, was the MS attached to the car? Just being in the MS shouldn't change the reading you get with an ohm meter that much, but if you had it hooked up to the car or the stim when you measured, the measured values will probably be nowhere near what you expect.

 

No, the MS was out of the car when I measured it, completely disconnected from everything else...hopefully this was the problem trying to start it.. Wish me luck today!

 

Okay...well- I checked the resistor values again, it seems they were correct and you were right Muy. I must have measured it with the stim plugged in. I'm going to try running easytherm and putting in the values again.

 

So, I updated the easytherm values on the MS plugged it all in and tried to start the car again with a fresh battery.

This time not even a single stumble. When I looked at the screen, PW1 was reading 0. So I tried cranking again, and sure enough the RPM was reading 0 as well.

Does MS get its rpm signal from the CAS? the coils?

I had also updated my firmware to the latest one on the extra site...029s I think. Could that be my latest problem?

 

If you updated the firmware, you will have to reload your settings.

It gets the rpm signal from the CAS.

 

Ah...so simply opening the MSQ won't work?


EDIT- and by opening, i mean re-burning the values to the MS as well

EDIT 2- Also, it sees RPM when attached to the stim with the stim wheel setting turned on

 

loading and reburning should work.

If you're not seeing rpm after the reflash, try reflashing the older revision and see what happens.... the change in 029s was for wheel decoding, and may have caused a problem.

One thing you should learn to do when debugging a problem is to only change one variable at a time...

So change the sensor calibrations first, then if that works, try the new firmware, etc....

 

Good point Muy, wish I had done that.

But, I have good news and bad news!

I got the rpm signal back, I don't know what I did, since I didn't change any settings, but they're back! So, I started cranking again, got a stumble. Increased the cranking pulsewidths, and the gauge on megatune showed the right pw. Sweet.

So, the increased fuel reduced the stumbling, so I reduced it. The engine caught for a few revolutions then died- first time ever without starter fluid. So, I reduced it even more, the engine ran for a good 5 seconds! So I figure I should reduce my req fuel settings as after it started running, the pulsewidths went up from my 8 at cranking to 12 and thats when the engine died.

So, I dropped the req fuel slightly, go to turn the key and the car goes pfffft. Nothing. Everything died. I check my battery terminals, start looking at all fuses, and everything is good. I look under the car, and sure enough, my + battery wire was hanging down. (Battery is behind the pass seat). Seems like all that cranking the starter combined with a bad crimp shook the cable off the terminal on the starter.

So, all in all- wasn't a total loss. I have my MS running proper, I know what setting to change tomorrow and I'll get a new starter terminal for the cable tomorrow. Though it seems some unknown force doesn't want this car to start... mother nature perhaps?

Thanks for all the support though, hopefully tomorrow I'll have some great news for you guys!

 

After re-loading an .msq file, you need to power-cycle the MS, as some of those settings are read in during boot only. To confirm proper thermistor calibration, you should see air and coolant temps nearly identical (3-4 degrees spread at most) after the engine sits for an extended period of time.

Sounds like you are making progress. Are you in an area where you can try pull-starting? That would be easier on the starting system, and could get the engine rpm up higher where dynamic compression will be better than that you'd see while cranking. An old engine of unknown pedigree may need just that.

If you have flooded the engine multiple times during the start attempts, you could also squirt a bit of oil into the chambers to improve sealing. There's a good chance the engine oil is contaminated as well, so change that out after the first bit of running.

 

Glad to hear you've got it catching and trying to run. If you're tinkering with req_fuel to keep it running, then you've been reading the megasquirt docs, so that's a good thing!

Renns also has a good point about restarting the MS after loading settings.

Finally, once you settle on a req_fuel that allows the car to run, don't forget to set it back to the calculated value and rescale the VE table.... especially if you had to increase req_fuel to get it to run. Having a lower req_fuel can give better tuning resolution in the VE table to a point.

 

That makes sense renns, it must have had something to do with that. Also, i noticed the coolant and air temps were within 2 degrees today, I don't recall them being as close before. So I must have messed something up before.

Unfortunately, I can't pull start where I am. Im right in the middle of a busy residential neighbourhood. I'll definately try squirting some oil in there though, thanks for the tip.

Muy, I've definately been reading this forum and the megasquirt docs like a guidebook. So many of yours and Renns past posts have helped me out both here and on msefi. I'm surprised I made it this far without having to post anything before now. Also, its a good thing you mentioned the VE table rescaling, I probably wouldn't have thought of that.

Hopefully I'll have some good news to share tomorrow!

 

Well....looks like its over for now. I found out why its not starting, 0 compression on the rear rotor

 

Oh no... Sorry to hear that. Here's to hoping it's just stuck seals!

Was it dead on all faces, or one blip and two duds? If you can get your finger in the exhaust port you can check for existance of apex seals. Also, check to see if they spring back nicely when depressed, and run your fingernail across the face of the seal to see if you can feel any damage. If the seals are all in place but stuck, you might be able to loosen them with any of a variety of carbon-softening products you see discussed on this forum.

Be careful not to turn the engine over with your finger in there. It's tough getting your pinky out of the housing once it's sheared off and fallen inside!

 

I'm really hoping its stuck seals. It seems like thats what it is, as the seals appear to be there and intact through the leading plug hole. I don't know if I can get the turbo manifold off without pulling the engine to look through the exhaust ports. As you probably know on your car, theres very littel clearance on that side. I'll have to take a look.

The front rotor has 105 psi on a cold and dry crank. The rear has 0. I've been reading those carbon softening threads, and I've got some MMO handy. So I'm going to try soaking the rotor overnight and see what that does. I'll try not to lose any fingers, then I'd definately have to crack open the engine...

I've got to move to Waterloo on saturday, and I'm running out of time...