'70 Dart 392 Project; what direction?

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Use the "Diagnostics and High Speed Loggers" tab at the top to view the cam and crank signals.

These are my settings, which are likely the same as yours if you copied the DIY site.
View attachment 1716274672

If you used a generic analog input for the oil pressure, you need to figure out what input you used and scale the sensor. Under advanced Engine tab, select Generic Sensor inputs. Choose the source, name it whatever you want, then enter the scale. On this same section, under tools, there is a sensor scaling tool if needed.

View attachment 1716274675

Are you a pre 2011 gen 3 hemi? According to both the manual and diy website those are the settings for a non VVT gen 3.
This page shows both settings if you scroll down a bit.

How to MegaSquirt Your Chrysler Hemi Engine
 
This is what the diagnostic and high speed logger tab looks like on mine. Where do I select inputs like cap sensor to view? I’m sure it’s right in front of me……

IMG_1635.jpeg
 
Alright now we're getting somewhere!
I had the idea to test the voltage at the connector on my daily driver (ram 1500 5.7hemi) and was getting 5V on signal and 5V on reference. I was only getting 2.39V on my signal wire.

Called DIYAutotune and talked to Steve. He had me jumper in a 3K resistor between the signal/5v ref wires and bingo 4.98V on the signal wire. Same thing on the cam sensor. RPM successfully sync'd!

While testing coils the aftermarket fuel line quick connect plastic fitting on the fuel rail let go and shot a 60psi stream of fuel all over the engine bay and myself.... that was fun, glad I wasn't actively testing spark at that moment! Grabbed the OEM connector clip and no more leaking. Got that problem solved.

Tested spark and no spark. Went through wiring diagrams and while I had everything connected according to MS manual, they don't reference a relay activated power source for the coil packs. Spliced into the O2 sensor relay to the coil packs and boom we've got spark!

First crank and she caught and fired right up! to 3,000 RPM's..... forgot to plug the old MAP sensor port on intake. Got that plugged.

She revs good, has 60PSI oil pressure, no leaks anywhere. Progress!

Now the bad:
After she catches kpa reading on MAP goes to about 30kPa. Not sure if that's normal or indicative of another vacuum leak.

She fires to 800 RPM then after a second climbs to 1750rpm-ish.

My O2 sensors are reading Error 9. Low voltage. Need to dig into the relay wiring with my meter and see whats what.... Pulled a datalog and will try to interpret what I can find.

Also now that everything is confirmed hooked up correctly (minus the O2 sensor voltage issue) I need to wire loom and high temp tape some wires before I dig into tuning too much.

I went ahead and put the header collectors on and slipped the Borla muffler onto the collector extensions for now to try and get an accurate O2 sensor reading. Won't be able to tell until I get the voltage on the O2 controllers where it needs to be.

Thanks for the help everyone! The saga continues....

MIke @ HCA
 
Alright now we're getting somewhere!
I had the idea to test the voltage at the connector on my daily driver (ram 1500 5.7hemi) and was getting 5V on signal and 5V on reference. I was only getting 2.39V on my signal wire.

Called DIYAutotune and talked to Steve. He had me jumper in a 3K resistor between the signal/5v ref wires and bingo 4.98V on the signal wire. Same thing on the cam sensor. RPM successfully sync'd!

While testing coils the aftermarket fuel line quick connect plastic fitting on the fuel rail let go and shot a 60psi stream of fuel all over the engine bay and myself.... that was fun, glad I wasn't actively testing spark at that moment! Grabbed the OEM connector clip and no more leaking. Got that problem solved.

Tested spark and no spark. Went through wiring diagrams and while I had everything connected according to MS manual, they don't reference a relay activated power source for the coil packs. Spliced into the O2 sensor relay to the coil packs and boom we've got spark!

First crank and she caught and fired right up! to 3,000 RPM's..... forgot to plug the old MAP sensor port on intake. Got that plugged.

She revs good, has 60PSI oil pressure, no leaks anywhere. Progress!

Now the bad:
After she catches kpa reading on MAP goes to about 30kPa. Not sure if that's normal or indicative of another vacuum leak.

She fires to 800 RPM then after a second climbs to 1750rpm-ish.

My O2 sensors are reading Error 9. Low voltage. Need to dig into the relay wiring with my meter and see whats what.... Pulled a datalog and will try to interpret what I can find.

Also now that everything is confirmed hooked up correctly (minus the O2 sensor voltage issue) I need to wire loom and high temp tape some wires before I dig into tuning too much.

I went ahead and put the header collectors on and slipped the Borla muffler onto the collector extensions for now to try and get an accurate O2 sensor reading. Won't be able to tell until I get the voltage on the O2 controllers where it needs to be.

Thanks for the help everyone! The saga continues....

MIke @ HCA
Awesome! I know it’s a great feeling when they finally make noise.
I guess I forgot I have pull up resistors on my cam and crank signals from when I ran the small block. I have them made into the harness inside the car.
30KPA is normal. Mine idles around 45 and I have an aftermarket cam. 100kpa is atmospheric pressure, so wide open.
The rising rpm sounds like the IAC is functioning backwards.
 
Awesome! I know it’s a great feeling when they finally make noise.
I guess I forgot I have pull up resistors on my cam and crank signals from when I ran the small block. I have them made into the harness inside the car.
30KPA is normal. Mine idles around 45 and I have an aftermarket cam. 100kpa is atmospheric pressure, so wide open.
The rising rpm sounds like the IAC is functioning backwards.
Its easy to forget those things! I know the DIYAutoTune usually sets up the assembled boxes for your application and there wasn’t anything in the manual about it. Easy fix though.

Man she sounds nasty though when you rev it! Super stoked!

I will definitely dig into the idle valve. I “guessed” a little based on my meter resistance readings on setup for that.

Mike
 
Its easy to forget those things! I know the DIYAutoTune usually sets up the assembled boxes for your application and there wasn’t anything in the manual about it. Easy fix though.

Man she sounds nasty though when you rev it! Super stoked!

I will definitely dig into the idle valve. I “guessed” a little based on my meter resistance readings on setup for that.

Mike
I think the idle valve is always a guess. It's easy to determine which pins are the coils, but the polarity is a shot in the dark. Mine seemed like it was correct initially, but quickly realized it only moved one direction. It's as simply as reversing polarity one of the coils to make it correct. The "output test mode-stepper motor" feature under "CAN-bus/testmodes will be your friend in getting the IAC right. I've always said setting up the IAC on tuner studio is by far the most frustrating thing of the whole system. The problem with the IAC is the ECM doesn't have any feedback from it to know where it is. When getting your start right, often times the IAC can miss some steps if the engine doesn't start cleanly. You'll end up with a high idle but the steps in tuner studio are showing the correct value. The only way to correct this is turn it off and start over with a clean start. I've never had any luck with closed loop idle either. I tried many times, but I found it best to just leave it run open loop based on temperature, then set your idle VE and ignition advance. However, I have noticed this G3 Hemi doesn't respond to timing changes at idle like my small block did. The hemi doesn't seem to care what idle timing is, unless you go to extremes.
 
I think the idle valve is always a guess. It's easy to determine which pins are the coils, but the polarity is a shot in the dark. Mine seemed like it was correct initially, but quickly realized it only moved one direction. It's as simply as reversing polarity one of the coils to make it correct. The "output test mode-stepper motor" feature under "CAN-bus/testmodes will be your friend in getting the IAC right. I've always said setting up the IAC on tuner studio is by far the most frustrating thing of the whole system. The problem with the IAC is the ECM doesn't have any feedback from it to know where it is. When getting your start right, often times the IAC can miss some steps if the engine doesn't start cleanly. You'll end up with a high idle but the steps in tuner studio are showing the correct value. The only way to correct this is turn it off and start over with a clean start. I've never had any luck with closed loop idle either. I tried many times, but I found it best to just leave it run open loop based on temperature, then set your idle VE and ignition advance. However, I have noticed this G3 Hemi doesn't respond to timing changes at idle like my small block did. The hemi doesn't seem to care what idle timing is, unless you go to extremes.

I HATE guessing lol
Turns out I had my idle screw on the throttle valve about 3/4 turn too much and it was causing a high idle. Now that I figured that out, I discovered that my Holley alternator isn't charging. Charging "+" post (one post alternator) is only reading 11.7V while running, which is throwing my O2 sensors off and they're showing an E9 error for low voltage.... So the computer can't make any adjustments to fuel without the O2 sensors working. It's only doing timing adjustments. Sent an email to Holley about it.

I finally removed the IAC valve from the TB and under the "test" function, if I "Home" the IAC the plunger extends (which would restrict airflow past the throttle body), and in the "run" position it retracts which would allow air flow. The HOME function bottoms out the plunger which blocks off all airflow. Then the "run" step size down from that retracts the plunger the specified amount to allow air behind the throttle blade. I've played with this darn thing all day and haven't made any improvements. If I home it, it blocks off all airflow and kills the engine. It will high idle and rev great above 1150RPM but if it goes below 1000RPM for more than 1 second it putters and dies. The exhaust smells extremely rich, I think I need my O2 sensor issue fixed before I can dial in this idle.

Have tried fixed timing at 10/15/20 degrees with no improvement. The preloaded tuned that came with the ECU has upwards of 35degrees timing and that only helps so far in that it keeps idle over 1,100RPM.


Mike
 
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I HATE guessing lol
The guys at DIY for this function just keep referring me to the manual saying "It explains it pretty good" but there's nothing in there that explains what I need it to.

I finally removed the IAC valve from the TB and under the "test" function, if I "Home" the IAC the plunger extends (which would restrict airflow past the throttle body), and in the "run" position it retrats which would allow air flow. I need to know if the "home" function is supposed to restrict airflow or not. It doesn't make sense that it would because if you allow more air (like a vacuum leak) then idle goes up... So I think it's wired backwards.

Also my Holley alternator isn't charging. Charging "+" post (one post alternator) is only reading 11.7V while running, which is throwing my O2 sensors off and they're showing an E9 error for low voltage....

Mike
Reference what I mentioned above that the ECU doesn't know the physical position of the IAC. If you pulled the IAC out and operated it, you probably noticed that once its pulled in all the way, it still steps but it doesn't move. There's some type of clutch in it to prevent damage. So, knowing this, the only way to the ECU to have repeatable steps to your desired position is to always start at one of the extremes, either all the way in or all the way out. That's why it says to set the homing steps larger than your maximum steps. You can choose the homing direction under the idle control tab. If you have homing direction set to closed, you have your polarity correct for that coil. In my opinion, you want homing direction closed. I have my homing steps set at 300. This guarantees it's closed all the way when the key is turned on. After that, it will go to the setpoint you have in the idle cranking duty/steps curve. There's plenty of time for it to make both of those moves if you wait until the fuel pump finishes priming.
I would install the IAC, make it move 250+ steps to home (closed), then unplug it and take it out to make sure it is in a position that appears closed.
After this, you can build a curve using the test mode by dialing up steps while the engine is running and up to temp. Record the amount of steps and RPM. Then you can make your warmup curve from there. Oh, you should also see the plunger move in (open) when using the test mode for run. If not, one of the coils is backwards.
On mine, I would have thought it would want 0 steps when the engine is full warm, but it doesn't. I'm around 35 steps at 200 degrees. I'm assuming that's from the aluminum expanding and closing up the tolerances.
I hope I explained this well. Honestly, the IAC is the biggest pain to get right with megasquirt. I've probably spent more time messing with that than I have anything else on it. Maybe I'm a dumbass, but like you said, their instructions aren't very intuitive.
 
Reference what I mentioned above that the ECU doesn't know the physical position of the IAC. If you pulled the IAC out and operated it, you probably noticed that once its pulled in all the way, it still steps but it doesn't move. There's some type of clutch in it to prevent damage. So, knowing this, the only way to the ECU to have repeatable steps to your desired position is to always start at one of the extremes, either all the way in or all the way out. That's why it says to set the homing steps larger than your maximum steps. You can choose the homing direction under the idle control tab. If you have homing direction set to closed, you have your polarity correct for that coil. In my opinion, you want homing direction closed. I have my homing steps set at 300. This guarantees it's closed all the way when the key is turned on. After that, it will go to the setpoint you have in the idle cranking duty/steps curve. There's plenty of time for it to make both of those moves if you wait until the fuel pump finishes priming.
I would install the IAC, make it move 250+ steps to home (closed), then unplug it and take it out to make sure it is in a position that appears closed.
After this, you can build a curve using the test mode by dialing up steps while the engine is running and up to temp. Record the amount of steps and RPM. Then you can make your warmup curve from there. Oh, you should also see the plunger move in (open) when using the test mode for run. If not, one of the coils is backwards.
On mine, I would have thought it would want 0 steps when the engine is full warm, but it doesn't. I'm around 35 steps at 200 degrees. I'm assuming that's from the aluminum expanding and closing up the tolerances.
I hope I explained this well. Honestly, the IAC is the biggest pain to get right with megasquirt. I've probably spent more time messing with that than I have anything else on it. Maybe I'm a dumbass, but like you said, their instructions aren't very intuitive.
I edited my post above yours to have some more info.

You're exactly right on it being a pain. I ended up measuring with calipers the "step" of a 50ms and it equaled right around .050" movement. With that in mind and taking some measurements I ended up with a guestimate of 265-290 steps to reach home (right in line with yours). I'm in a fairly hot shop and the engine temp got up to 190-205 today with all the high idle testing I'm doing but I got the fan control working and its keeping it at 200-205. So not really a "warm up" tune situation for most of the day.

I "stepped" it back in 25ms steps at a time in the test mode but it doesn't really seem to work. IT affected some small changes but nothing really eye opening. I really think my O2 sensors not working are messing with me. The actual settings limit you to 25 steps per movement and 25 steps initally from home. I played with these settings for a good 6 hours today and really didn't make much progress.

I also have a CAM sync error which puts the injectors into batch fire mode which might be part of my rich condition as it disables the sequential ignition/injection events. Guys at DIY suggested to still run the Hemi VVT setting but that didn't help. Because I'm running aftermarket cam I might have to go in and do a custom "poll" setting and count the teeth per dialogue and get it sync'd that way. They did look at my datalog and said it lost sync at the beginning but then had sync after that but it's still showing CAM sync error on the gauge display.

Not too much progress but we'll see what happens. Won't get back to it until monday....

Mike
 
Okay now that I've got some time to go over the manual, talk with a buddy of mine who does tuning, and research some more.
Game plan is to attempt to poll the cam sensor. If I can't get cam sync the engine automatically goes into batch injector and wasted spark operation. Not ideal... Looking at the manual and my data log it appears I can poll on tooth 10 "rising" after the missing tooth crank wheel signal. (this is getting complicated but it forces me to learn this stuff). According to the manual that might make the ECU happy.

ALSO! I'm an idiot and never knew that an alternator needed to be "turned on" to charge. Just always assumed if they were spinning they were charging. I've always said you don't know what you don't know. It's likely that with the hybrid of wiring I've got in this car that the 12V switched source that is part of the holley 4 wire connector isn't activating appropriately (never did check it, just wired it according to the painless wiring manual). But a quick search in the Megasquirt manual shows that I can control the alternator switching on with either a PWM output or a High Output signal from the ECU. Will get this done on monday and I think it'll help solve some issues.


If I can get my Cam sync solved and my alternator charging and keeping the O2 controller happy I should then be able to actually dig into this idle. I really think it's just loading fuel like crazy below 1000 RPM's and causing it to bog down and die. Exhaust was rich enough it wasn't pleasant on the eyes in the shop...

Mike
 
Okay now that I've got some time to go over the manual, talk with a buddy of mine who does tuning, and research some more.
Game plan is to attempt to poll the cam sensor. If I can't get cam sync the engine automatically goes into batch injector and wasted spark operation. Not ideal... Looking at the manual and my data log it appears I can poll on tooth 10 "rising" after the missing tooth crank wheel signal. (this is getting complicated but it forces me to learn this stuff). According to the manual that might make the ECU happy.

ALSO! I'm an idiot and never knew that an alternator needed to be "turned on" to charge. Just always assumed if they were spinning they were charging. I've always said you don't know what you don't know. It's likely that with the hybrid of wiring I've got in this car that the 12V switched source that is part of the holley 4 wire connector isn't activating appropriately (never did check it, just wired it according to the painless wiring manual). But a quick search in the Megasquirt manual shows that I can control the alternator switching on with either a PWM output or a High Output signal from the ECU. Will get this done on monday and I think it'll help solve some issues.

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If I can get my Cam sync solved and my alternator charging and keeping the O2 controller happy I should then be able to actually dig into this idle. I really think it's just loading fuel like crazy below 1000 RPM's and causing it to bog down and die. Exhaust was rich enough it wasn't pleasant on the eyes in the shop...

Mike
when I got my mega squirt gold box up and running it ran very rich at idle witch was at 1000 rpm. When I started driving it would back fire ,sputter and fart for the first ten miles using the auto tune feature in Tuner studio but then everything smoothed out but I still had to change the fuel table to get idle to 14.7 to 1 ( burning eyes ) the car is very streetable hot or cold. The only issue I have is it does not make the power it should. I am trying to learn how to tune on my own using carborater knowledge. My Hemi swap turned my duster from a high 11 second car to a 14 second car. I may get it dyno tuned before instead of guessing
 
when I got my mega squirt gold box up and running it ran very rich at idle witch was at 1000 rpm. When I started driving it would back fire ,sputter and fart for the first ten miles using the auto tune feature in Tuner studio but then everything smoothed out but I still had to change the fuel table to get idle to 14.7 to 1 ( burning eyes ) the car is very streetable hot or cold. The only issue I have is it does not make the power it should. I am trying to learn how to tune on my own using carborater knowledge. My Hemi swap turned my duster from a high 11 second car to a 14 second car. I may get it dyno tuned before instead of guessing
That would be incredibly frustrating!

I had about 20 mins in the shop today and I put a 12V jumper wire to my alternator and bingo, I’ve got AFR and no cutout on my gauges!

Also in my ignition setup screen I changed my cam input to poll on tooth #10 AND changed startup to wait for cam input and now I don’t have a cam sync fault! Progress.
Car also was able to idle on its own after giving it a little fuel after initial startup. Looking forward to digging into idle more tomorrow.

I saw on a YouTube video yesterday that unless you run legit ethanol free gasoline that stoichiometric is actually 14:1 not 14.7:1. I’m going to keep that in mind as I tune. Will keep everyone posted.

Mike
 
That would be incredibly frustrating!

I had about 20 mins in the shop today and I put a 12V jumper wire to my alternator and bingo, I’ve got AFR and no cutout on my gauges!

Also in my ignition setup screen I changed my cam input to poll on tooth #10 AND changed startup to wait for cam input and now I don’t have a cam sync fault! Progress.
Car also was able to idle on its own after giving it a little fuel after initial startup. Looking forward to digging into idle more tomorrow.

I saw on a YouTube video yesterday that unless you run legit ethanol free gasoline that stoichiometric is actually 14:1 not 14.7:1. I’m going to keep that in mind as I tune. Will keep everyone posted.

Mike
Glad you are making some progress. There's always that "Ah-Ha" moment when things start to work.

You know, the thought of adjusting stoich for modern fuel with ethanol in it never crossed my mind. The problem is you'll never know what ethanol content you have unless you use a flex fuel sensor. I considered adding one just so I can run E85, but the closest gas station to me that offers it is about 30 miles away, and more importantly, I'm out of analog inputs on my MS3X. I'd have to add a micosquirt or one of the digital displays that have extra inputs. I'm not looking to spend thousands just to have flex fuel that isn't even convenient to get.
This being said, I really don't run mine at 14.7 anywhere except for cruising RPM. My idle is usually around 14.2-14.5.
 
Wish I could post a video on here!
Got it running better a bit today and even drive it around the block!

Will post more details tomorrow but it was a good day!
 
Wish I could post a video on here!
Got it running better a bit today and even drive it around the block!

Will post more details tomorrow but it was a good day!
You can make a short youtube video and post the link...
 
You can make a short youtube video and post the link...

Here ya go! Obviously just with some exhaust pipe slipped onto the mufflers/collectors but it gives you an idea.



Couple technical updates. With the issues I’ve had getting a decent idle and AFR I checked my injectors again and they are for sure NOT OEM injectors and have zero markings on them to identify flow rate or size. Rather than mess around with sending them off to get flow tested I have a set of hellcat 600cc injectors on the way. There’s a seller on FB marketplace selling sets of 8 new in box for $385. Found that hard to beat and I’ve been fairly impressed with OEM quality stuff the last 10 years.

I pulled a plug and it was coated in soot, insanely rich. What finally got me down to a decent idle was taking a guess at my actual injector size and putting in 650 vs 455 and the idle cleaned up a lot. So I’m hoping having appropriately known sized injectors will help shorten the path to a decent tune.


Working on exhaust today hope to have it buttoned up and clean up some more wiring under the dash. It will be leaving end of next week for my buddies shop to help me finish interior. Ordered carpet and some other knick knacks for the interior last night.

Mike

IMG_1666.jpeg
 
Another update. Had numerous small problems as you always do with a new build.
Installed the new 600cc hellcat injectors and things are much better initially.

The Holley oil pan just would not seal and kept leaking oil. Not a terrible leak but unacceptable. Changed out the break in oil and dropped the pan and reinforced their O-ring gasket with a liberal amount of black RTV. Also had to helicoil one of their oil pan holes on the aluminum front cover. Replaced the bolts with a true grade 5 bolt as well as the threads stretched on another one with fairly minimal tightening.

I was having an issue with 2nd gear. With easy driving around the block the trans shifted like butter. Very very smooth. However if I accelerated hard in 1st, it would hit a WALL going into 2nd gear. No grinding, no weird noises. Just a hard wall. If I shifted to 4th and back to 2nd it would fall in. Was a little nervous about this one but found a post on FBBO where the guy had the same issue and the ball on the reverse detent had fallen out. I popped the cover off the trans and sure enough no detent ball. Fished around in the bottom with a magnet and bingo found it! Got it back in and reverse actually engages much more solidly now and I dont' anticipate the 2nd gear issue. I believe the reverse lever was getting pushed back under hard acceleration and blocking off 2nd gear somehow.

EFI tuning update: Got things working OK for now. I was focused too much on the IAC allowed movements and not the warm up cycles. Playing with it and it's getting better.

Hot starts were not cooperating. Lots of cranking. Trying to sort this out. Fuel pressure was bleeding off almost immediately after initial prime, installed a check valve back near the fuel tank and it's holding much better but still bleeds off in 5-10 seconds now rather than 1 second like it was doing prior.

Got timing and VE table tuned a bit to where it recovers fairly decent after revving up, but when under a slight load like backing out of the shop it's bogging down, I believe it's too rich in that area of the VE table but I need someone there to help me with it.

Also, I have a weird lean bank issue. Drivers side exhaust pipe past the collector shows more heat discoloration than the passenger side, so I don't think my O2 sensors are misreading. It "seems" to be more consistent when it's cool but after a few hours of playing with idle settings the drivers side leans out. Need to dig into this one.

Car is going to my buddies shop on Monday for glass/interior/carpet/headliner work and I"m going to take a few weeks off from working on the car. It's been great to get it this far, and the car absolutely rips down the road and the 315 tires hook up fantastically.

Got the exhaust all fabbed up and it looks great. I'll follow up with some pictures. Wasn't near as hard as I thought it would be to route the dual 3" pipes up over the rear axle and outside the relocated leaf springs.

Mike
 
Pic of the exhaust tips running out the back. This was before the final hangers were installed so they’re actually even height. I used V band flanges on the mufflers in front of the rear axle so it’s an easy system to take out. You can snake them out the back pretty easy then the collectors just unbolt. Hanger locations are the rear seat bolts and the old rear leaf spring hanger locations.
So far around the block it sounds very good and no drone. We’ll see how it does on the highway.

IMG_1737.jpeg
 
Little more progress Friday. Turns out when I replaced the gasket on the reverse detent plunger that the steel ball fell out and it was only the spring against the reverse lever. I pulled side cover, fished around and found the ball in the bottom with a magnet and got it back in place. Trans shifts perfectly now! Much relieved and that 1-2 shift is so fun!

Also I went through the O2 sensor settings, had the correct injector groupings but they were on the wrong sensors. so it was reading left bank as right bank and vice versa. Seems to have fixed my initial mismatched O2 sensor readings and explains why the more I adjusted settings the worse things got.

Need to play more with IAC settings on the warmup pulses and the injector cranking pulses at various engine temps but we are getting closer.

A little frustrated that the only gauges that work on this refurbed gauge cluster is the amp and speedo. I’m thinking this winter I might redo the whole gauge cluster with new gauges.

Mike
 
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