1970s 40, 350/TH350 on Megasquirt 1 PCB3.0

[toyotaspeed90]

I really do enjoy reading about your problems. I'm looking at doing a boosted 3rz with a Megasquirt ECU and it's nice to see all this information!

If you have the coilpack version - throw EDIS with a 36-1 wheel on the crank and a sensor pointed at it, and you'll be ready to go with MS1 easily.

Those coilpacks, I believe, are the same used on the 7mgte which are also the same used on the JDM late model 4agze.

Those coilpacks work great with EDIS and give the install a nice stock look. (I ran a smallport JDM 4agze on MS1/EDIS).

Make sure to at least get a V3 board.

If you have a 95-2000 3RZ then I assume you have the bosch style top feed injectors, I'm not completely sure on their stock size, but if you're going mild boost, I might have the right injectors for you sitting around (low ohm supra/mr2 turbo 440 cc/min).

 

[toyotaspeed90]

Some screenshots attached.....

One thing to keep in mind, the algorithms used by MS1 and MS2 are different, so you can't necessarily take the required fuel/injector setting from one and dump it into the other. So there are some various changes (no, you don't need to know how any of the background works, the firmware helps you load those values, just saying you can't necessarily take a map/value from MS1 and throw it in MS2).

And the most important, which is the noise filtering. This works based on the values MS receives from the tach/distributor, and if a value is 30% higher than the previous value, then ignore it. This has resolved the tach/rpm issues.

 

[toyotaspeed90]

The software I purchased is extremely handy, the more I get to use it.

the startup sequence isn't as happy as it was with the tune I had in MS1 - it seems once it's running it has a bit of a lopey idle, but getting it to start and stay running (immediately) sometimes takes a few tries when cold.

I thought it was running overly rich.... like just dumping fuel..... to a point where I felt like I was doing a 'flood start'..... well, I was wrong, it's way too lean (high 15-high 16 AFR), which is the opposite of what you want when cold.....

This is a screenshot of the log (I had warmed up the O2 prior to starting)

 

[toyotaspeed90]

Still having issues with a lopey idle - to an extent that it's concerning.

I've considered swapping to a 4.3L v6, both to have room for a mechanical fan (reduce engine temps) and because there may be a mechanical issue with the 350. An opportunity for a 'free' 4.3L V6 with less than 5,000 miles came up (in a running/driving vehicle) - we took possession... and as it turns out the van is WAY too nice to simply cannibalize for the engine (not a fan of Astro vans at all, but wow, it's been meticulously maintained). We are waiting to hear if AZ will release the title or not - and if not, we'll get a sherrifs title to scrap it - and decisions will need to be made.

Either way - I decided that the 350 would need to be pulled apart in one way or another. Tearing it down (retaining valve cover, heads, down to oil pan in tact) and inspecting for any possible vacuum leaks or issues with the timing chain, and nothing came up - other than a couple possibilities of very minor vacuum leaks. I'm planning to throw it back together with new gaskets and see how it does.

Also, either way, I am ditching the mechanical distributor - while it's "new" - the engine was sold to me indicating it's an MSD unit, which is far from the truth - probably some cheap knock off. I'm not a professional when it comes to the spring tension or the vacuum advance mechanism, and there seems to be more play than I like.... plus Megasquirt is expecting a 'clean' spark value which (while MS2 has allowed me to filter it) it isn't getting.

So I have an electronic distributor that I'll be throwing in, and am in the works of modifying the MS2 for an HEI input.

There was previous discussion that the harmonic balancer may be broken, and as such is causing issues with timing - but that simply isn't the case. Harmonic balancer (and the pulleys) are in perfect order.

 

[GLTHFJ60]

@mtweller

Wicked build man.

 

[mtweller]

Do you have EGO correction correction locked out at idle RPMs? I had a lopey idle issue due to EGO corrections trying to chase any AFR deviances. I got my idle VE and warmup correction dialed in, with EGO correction disabled under 1k RPM, and that corrected my problem.

Nevermind, see it's off in the log. I'll read over this stuff later (work is busy today) and see if I have any advice. If you want, send me over your log file and I'll try to give it a look. I'm no tuner by any means, but have had to work through a number of issues on my own for my 2FE on a MS2.

 

[toyotaspeed90]

Once the vehicle is back to running condition I will. I rarely log the data, not sure if I posted it in this thread or not but I have a dedicated rPI with 7" touchscreen for on board tuning.

I did have a bit of an issue tuning while driving - where constant throttle seemed to cause "lopey" power where it felt that rpms and power would change with a constant load - the more it tuned the worse it got.

I backed that file off (reloading a previous tune) - then had the idea to recalibrate the O2 sensor, and tuning did seem to get better.


As a side note - most of my overly-detailed mechanical work is on Toyota's so my brain didn't have a chance to realize what was wrong with the intake install from the engines P.O. - As expected the ends (front/back) were sealed with RTV. As were the water ports, to ensure the gaskets sealed... AND the intake ports. Copper Permatex RTV - which is not ok to work in areas with fuel.

Was it causing a problem? Possibly, but won't be sure until it's back together. Did some light sanding to the intake manifold with 500 grit sandpaper and a wood block to get it mostly level - to remove small dings along all ports.

 

[toyotaspeed90]

Obligatory photo of unnecessarily maintained high mileage Astro van with 346,000 miles and over $13k in receipts since 290k miles....

 

[handcannon]

I have two Astro vans, and I'm sold on the Astro and the 4.3 motor. We have a 97 that we bought new, and a 98 that had somewhere around 180,000 on it when we got it. The 97 is parked at the moment (needs brakes, and no money for repairs), so we are driving the 98, which is at 282,000 miles now. I need to try to sell the 98 as we no longer have a need for that many vehicles. I wouldn't be afraid of having my daughter driving it across the country it is running that good.

The biggest problem I can see with using the 4.3 out of the Astro for the Landcruiser is that the RPM's need to be up a bit to get any power out of it. The 4.3 is not a low end torque motor. But, I've been spoiled by my diesel pickup. It has lots of low end TORQUE!

Don

 

[toyotaspeed90]

I agree, and I don't. It has good, comparable numbers. Make it breathe better with an edelbrock manifold, a 305/350 TBI, and a 250-270 cam - it will flatten the torque curve for added low end power and increase HP. I'm not sold on the idea and is why I'm spending money to work on the 350 first.

With that said - I learned that removing a SBC timing cover cover is easy with the oil pan on.... but if you mess up and try to reinstall with the pan, you just get a bent cover.

 

[toyotaspeed90]

Haven't had much time... picked up a new timing cover.... but haven't got it installed yet. I'm doing the 'loosen the front bolt and throw some small prybars between the block and pan' trick to lower the front of the pan enough to put the timing cover on. Just haven't done it yet (no time with work)

I will be following this to get the HEI dizzy up and going:
https://www.diyautotune.com/support/tech/install/chevrolet-gm/carb-to-efi/part2/

As a quick note - if you have a V3.0 board and you need to add the header pins - add them to the TOP, not the bottom. I thought putting them on the bottom would look better/cleaner (not sure why, since the case covers it all) - but they don't clear the lower case. So I had to desolder/pull them and resolder them.

I also got the intake manifold re-mounted (properly - with new small head intake bolts set to the proper torque... and no RTV on the intake ports). I block sanded the TBI and the adapter as well - the adapter having a bit of unevenness.... all back together with new (thick) gaskets. I did find an 'interesting' mild blowout of the TBI gasket (between the 2 sides)....

Will load some photos soon.

 

[handcannon]

The biggest problem I can see with using the 4.3 out of the Astro for the Landcruiser is that the RPM's need to be up a bit to get any power out of it. The 4.3 is not a low end torque motor. But, I've been spoiled by my diesel pickup. It has lots of low end TORQUE!

Don

I agree, and I don't. It has good, comparable numbers. Make it breathe better with an edelbrock manifold, a 305/350 TBI, and a 250-270 cam - it will flatten the torque curve for added low end power and increase HP. I'm not sold on the idea and is why I'm spending money to work on the 350 first.

Since I already have the two Astro vans I'm interested in what you are saying. Do you know of any links to a thread that details these mods? I would also be interested in any change in fuel mileage, good or bad. I currently don't have the funds to do anything, but I am definitely in the learning mode.

Don

 

[toyotaspeed90]

Since I already have the two Astro vans I'm interested in what you are saying. Do you know of any links to a thread that details these mods? I would also be interested in any change in fuel mileage, good or bad. I currently don't have the funds to do anything, but I am definitely in the learning mode.

Don

The intake manifold..... I'm still not 100% sure. What I can find online is that the Edelbrock manifolds (to effectively bolt on a carb for the Vortec motors) work up to 1995 and I believe I read it works for the balance shaft motors. My van is a 1995 and it has the stupid spider injector - which on this van has been replaced at least 3 times, last time less than 5k miles ago (so I know it's fine, but I still don't like them). If you don't know what that is - Chevy called it "central port injection" or CPI - which there is 1 large electronic connector for the (yes, one) injector at the top of the manifold. It has tubes that feed to each cylinder - at the end of the cylinder is a ball. When the pressure reaches high enough in the tube (with fuel - requires at least 60psi) the ball pops back and sprays fuel into that chamber. It's a bad design and the tubes harden/crack - leak - and then basically fill the intake (and engine) full of gas.

So, anything to get away from that IF (big IF) this engine goes into the cruiser.
Manifold:
Edelbrock Performer Intake Manifolds 2114

The cam - yeah, there are lots of cams available for the 4.3L V6. Aside what others on here say, negatively, about the 4.3L V6 (in comparison to a 350) - this engine was found in the likes of 1/2 ton trucks, the Astro vans, Chevy S10 trucks and S10/15 blazers. It was also a popular marine engine.

A while back I had a 1990 Bayliner Capri, it had a Mercruiser 4.3L with an Alpha 1 outdrive. As much as the marine community claims the "Merccruiser" is special, and different, from an Automotive engine (sometimes that's the case - like reverse rotation) - the engine in that boat was identical to an Automotive engine (of the same year) with a few exceptions:
Brass freeze plugs
The marine manifolds
A different cam

That engine went tits up with a rod knock. Oddly enough, this was about 7-8 years ago, I found an extremely low mileage 1995 4.3L from a Van - same vortec motor with the junk injector (literally just throw it out about a year ago). I swapped the cam at a low price (around $80) and had zero issues.

You can get larger cams that produce more/flatter power as well - some are more expensive because they come as a kit with additional parts. As an example:
COMP Cams High Energy Cam and Lifter Kits CL18-123-4

 

[handcannon]

Thank you for the info. Time to do some reading.

Don

 

[toyotaspeed90]

Back to the project (have had some delays with life happening)....

I got the diyautotune kit - the instructions I found were a bit vague - did some research and just went for it. We'll see how it goes. I originally had the pins and wires on the bottom of the board but the case didn't clear. Redid it with them on top - not overly happy with the placement of the pin/wire and the MS2 daughterboard... but oh well.

The kit I ordered is just 2 wires, 1 with a resistor, each wire having push on clips on the ends, and some pins for the board. I decided to use the pins (instead of just soldering the wire to the board) in the event something goes wrong - I can switch back to fuel only easily (or, much easier via ECU than swapping back to the mechanical dizzy - although I might be able to even run the HEI dizzy sans megasquirt with it set to the constant timing if in a pinch - I know EDIS allows for that).

In putting the engine back together I found the timing chain cover to be a pain - it's not on yet - while I was able to successfully get the front of the pan lowered enough to reinstall the chain cover, one of the prybars ate into the pan gasket.... so I'll just be pulling the pan, installing the timing cover, and reinstalling the pan.

Some photos:

 

[toyotaspeed90]

Well..... technically the chain cover and oil pan are re-installed.

The Felpro Permadry one piece oil pan gasket set is a nightmare to install... at least in this vehicle. It comes with plastic studs which are supposed to be screwed into the 4 corner bolts of the oil pan - then push the gasket onto the studs, then the pan onto the studs.

On my vehicle, one wasn't possible to install (starter and driveshaft in the way) - so I didn't use it there.

The gasket is much thicker than cork - and it comes with new pan bolts (the smaller ones). Instructions state to flatten bolt holes on the pan (if they aren't) - which I did.

The studs hold the gasket and the pan in place decently, but not great. The bolts they provide really aren't long enough unless you start pushing the pan and gasket up towards the engine - which is fine at first.

I tried installing bolts in a circular pattern, of sorts - to get the pan up and flat as possible. As it would turn out - the timing cover side has a lot of "crush" that's needed to get into the timing cover itself - and the ONLY way I could get this was by starting at the back of the pan moving up. Then going back over the bolts over and over and over again.

I had everything installed (mind you, this took over an hour just to install oil pan bolts) - and I pulled the "studs". Back bolts were no problem. Front bolts..... I was able to just *barely* get one in - and as I did, I watched the other side pull away from the block.

There was a nearly 1/3" gap between oil pan and engine block at the last corner bolt - WITH all bolts tightened (that I could tell).

I was able to rip the locking nut off the last corner bolt itself, and have *just* enough threads to grab and finally tighten it down. Then went back over all bolts.

I'm 99% sure installing this has warped the oil pan, and I will have a leak.

If Felpro is making a specialty plastic stud for this application only - why wouldn't they just include steel studs and nuts to make the job easier for the installer and cheaper for them to produce.....

 

[toyotaspeed90]

Finally got some more time to work on it, a little bit.

The modifications to the ECU don't seem to be working - it isn't getting any kind of signal from the distributor. I know it, and the new coil, are wired properly as it's sending spark and the tach (gauge in the car) is registering while cranking - and I've triple checked everything else. I've reached out to DIYAutoTune as it's their "upgrade" kit I bought and it's them who wrote the article, we'll see if or how quickly they respond.

I was curious - and I went back through the build instructions and compared fuel only vs Hall/Opto circuits and they're nearly identical. In fact, it will just be a matter of removing a few components and adding jumpers. I wish I had just gone through those instructions before as I think it would have been, overall, easier than using the simple "upgrade" kit.

 

[toyotaspeed90]

For anyone following, I'm now sort of "typing out loud" and curious on your thoughts, while I impatiently wait for a response from diyautotune.

The instructions for the Hall/Opto and the triggering off the coil negative seem very different when you initially read them. That's why I went with the "easy kit". The more I read into it the less I understand how the "easy kit" is supposed to work.

Here is the instruction set for fuel only (reading coil negative):

1. Install and solder R12 {390H-ND, 390 Ohm, ½ watt, orange-white-brown}. This is installed between the resistors you have just been installing and the CPU socket. This resistor should be mounted roughly 1/8" (3mm) above the surface of the PCB. Also, the value of this resistor may have to be changed if you trigger from the negative side of the coil depending on application - start with the supplied value, and if gets hot while the engine is running, then increase the value, in steps, up to 10K (like 470 Ohms, 560 Ohms, 680 Ohms, 1K, ...), or even more in some applications (consult the MegaSquirt Forums list for advice). However, do not adjust this resistor on assembly, unless you have a good reason to do so.
2. Install and solder R13 {4.7KEBK-ND, 4.7k, yellow-violet-red}. This is located 3 places close to the heat sink than R12 (which you just installed).
3. Install and solder D1 {1N4001DICT-ND}. This is the famous Wing Diode - you will want this if you are triggering off the negative side of the coil - such as with points (reduces tach signal false-triggering).
4. In the place of D2, install a 22V or 24V Zener diode {1N4748A-ND}, in the reverse of the indicted orientation (i.e., put the band at the other end rather than that indicated on the silk screen). Note that the stim will not be able to send a signal through this diode. If you have installed it, jumper it for operating on the stim. Later, when MegaSquirt® is installed in the vehicle, you should remove the jumper. If you find that the tach signal sometimes jumps too high (20000 rpm or more) you can either replace the D2 Zener with one having a higher voltage rating (28, 32 or 36 Volts), or add one or more 5.6 Volt or higher Zener diodes in series into the tach input wire to DB37 pin #24 (the banded end of the diode(s) should be closest to the negative coil terminal).
5. Install/solder opto-isolator U3 {160-1300-5-ND, 4N25). This is located near the center of the PCB. If you have bought a socket (AE10021-ND ) for this component, solder it in place instead, then insert U3 into the socket. Observe the proper orientation (notch matches PCB - towards the heat sink, or dot for pin #1 which is the square pad on PCB at the notched end of the silk screen). If neither are there, hold the chip so that the writing is facing you and the right way around. Pin #1 is on the bottom left.
6. Install and solder C11 {399-4326-ND, 0.01µF, 103 marking}. This installs at the top of the row of 'vertically' oriented capacitors above "Bowling" in the copyright notice.
7. If you are going to use the negative side of the coil to trigger MegaSquirt® (I.e., you are not using ignition timing control), then install and solder C30 {399-4353-ND, 0.22µF, 224 marking}.
8. If you are going to use the negative side of the coil to trigger MegaSquirt® (I.e., you are not using ignition timing control), then install and solder C12, the Ed capacitor (399-4202-ND, 0.001 µF, 102 marking}. This is located above "Bowling" in the copyright notice. The value of this capacitor may need to be increased if there are noise problems with the tach signal - values up to 0.1µF will work. The 0.001µF value is a good starting point

Here is the HEI Mod kit instructions:

1. Remove the TachSelect to OptoIn jumper, and the XG1-XG2 jumper. You won’t need them anymore while running HEI ignition.
2. The Red (resistor) wire runs from the #3 pin (OptoIn) to the 5v Pin near the MS2 Daughterboard.
3. The Green (no resistor) wire runs from the TachSelect pin (middle of JP1) over to the XG1 pin.
4. That’s it. But for the more visually inclined learners, how about a video?

You can see why I went this route - simple. Remove 2 jumpers, run a couple wires and done.

For wiring this, the instructions are:

1. G (Ground): Wire to TPS Ret on the Relay Board
   
   
2. B (5V): Wire to VREF on the Relay Board
   
   
3. R (Signal from Reluctor/Module to ECU): Wire to TACH on the Relay Board
   
   
4. E (Signal from ECU to HEI Module to fire the coil): Wire to S5 on the Relay Board (S5 goes back to pin36 on MegaSquirt)

G goes to the TPS/sensor return, B goes to the 5V Vref this circuit supposedly creates on pin 6, R goes to Tach on pin 24, and E goes to pin 36.

They suggest to not use the "HEI" option in the software as they are using a different circuit - but I can't quite understand it.


Here are the instructions for installing the Hall/Opto circuit (and I'll touch on this in a bit):

1. Install and solder R12 {390H-ND, 390 Ohm, ½ watt, orange-white-brown}. This is installed between the resistors you have just been installing and the CPU socket. This resistor should be mounted roughly 1/8" (3mm) above the surface of the PCB. Also, the value of this resistor may have to be changed if you trigger from the negative side of the coil depending on application - start with the supplied value, and if gets hot while the engine is running, then increase the value, in steps, up to 10K (like 470 Ohms, 560 Ohms, 680 Ohms, 1K, ...), or even more in some applications (consult the MegaSquirt Forums list for advice). However, do not adjust this resistor on assembly, unless you have a good reason to do so.
2. Install and solder R13 {4.7KEBK-ND, 4.7k, yellow-violet-red}. This is located 3 places close to the heat sink than R12 (which you just installed).
3. Install and solder C11 {399-4326-ND, 0.01µF, 103 marking}. This installs at the top of the row of 'vertically' oriented capacitors above "Bowling" in the copyright notice.
4. Leave the C30 location empty - DO NOT jumper it.
5. If you have a Hall sensor or optical sensor, do not install D1, put a jumper in its place. It is located beside R12, further from the heat sink.
6. For most installations, diode D2 {1N4001DICT-ND, the marked 1N4001} is not needed. Do not install D2, install a jumper (made from a snipped off lead) in its place. It is located beside D1, closer to the heat sink.Note: this diode (D2) is needed only if the ignition system has a large offset bias - most systems do not have such a bias. So, to start, you can either solder in a jumper wire in this location, or, you can install the diode D2, and then install a jumper around the two leads of the diode - in effect shorting it out. The latter will allow you to snip the jumper later on if needed, putting the diode back in circuit. Solder the diode in observing the banded end as on the board, then solder a wire jumper across the diode itself.
7. Install/solder opto-isolator U3 {160-1300-5-ND, 4N25). This is located near the center of the PCB. If you have bought a socket (AE7300-ND or AE10021-ND ) for this component, solder it in place instead, then insert U3 into the socket. Observe the proper orientation (notchmatches PCB - towards the heat sink, or dot for pin #1 which is the square pad on PCB at the notched end of the silk screen). If neither are there, hold the chip so that the writing is facing you and the right way around. Pin #1 is on the bottom left.
8. Leave the C12 location empty - DO NOT jumper it. This is located above "Bowling" in the copyright notice. This capacitor may need to be installed and/or the value increased if there are noise problems with the tach signal - values up to 0.1µF will work. The 0.001µF value is a good starting point.

Then it suggest to wire it as:
G goes to ground (TPS ground return works here), B goes to the 5V Vref on pin 26, R goes to Tach on pin 24, and E goes to pin 36.


So the wiring is identical with the exception of putting the VREF on pin 6 instead of pin 26 - which bugs me, since the "easy kit" instructions have you remove all of the jumpers that the hall circuit requires.



So I sat down and read the build instructions for installing the ignition circuits, to really just pare it down to the minimum of what is required to be done. I literally wrote out what components to install or not install in the "Hall/Opto" circuit, then went through the fuel only circuit, and check marked if the same, or made a note where different.


The only difference between the 2 above is:
Leave C30 empty (so for my install, remove C30)
Do not install D1 for Hall sensor setup, but jumper (so for my install, remove D1 and jumper)
Jumper D2 (install a jumper across the D2 legs for now/testing)
Leave C12 empty (so for my install, remove C12)


Then install jumpers on:
XG1 to XG2 (was there, removed per the "easy kit" instructions)
OptoIn to TachSelect (was there, removed per the "easy kit" instructions)
TSEL to OptoOut (don't recall)
JS10 to IGN


So, the "easy kit" doesn't seem to work, requires seemingly important jumpers to be removed and I am not getting an ignition signal (and I know it's working). To undo the "easy" kit is simply pulling the wires off - then to install the HEI circuit is simply removing 3 simple components and installing 5 jumpers.


I really wish I had just read the instructions before-hand and just done the latter.


Is there something I'm missing that should, in fact, make my setup with the "easy kit" work?

*edit*
It should be noted - for the HEI components - I can get spark without megasquirt installed. Similar to some DIS systems, it's a stand alone system that will revert to a static ignition timing if it doesn't receive a signal to change ignition advance/retard. So the HEI is working (and I checked spark at plug #1) and the only purpose of VREF is to tell the module to receive the advance/retard signal from the ECU. Sending the signal (and MS receiving it) should be the same on both circuits and should receive without sending anything. Note that the only difference in wiring is, in fact, the VREF circuit - in theory, even if something is wrong with that piece it should be receiving a signal just not advancing timing.

 

[toyotaspeed90]

So progress!

Not happy with the 'promise' that comes with the DIYAututune HEI kit of it being easy. The instructions just don't make sense.

For instance - they have you wire the 5V v-ref to pin 6 (as I mentioned above). Well if you go back a few pages in this thread, you'll see that I followed instructions to send a ground through pin 6 - which uses a "spare" I/O port, connected to SPR4 (spare 4). The DIY instructions don't mention doing anything with SPR4. So with their kit installed, pin 6 goes nowhere since Pin 6/SPR4 goes nowhere per their instructions. Just doesn't make sense.


So I did as mentioned above....

Removed C30, Removed D1 and installed a jumper, Jumper D2 (for now), remove C12, then jumper XG1 to XG2, OPTOIN to TachSelect, TSEL to OptoOut, and JS10 to IGN.

I'm getting a signal, and it is getting spark and fuel. There's either an issue with timing or an ignition setting is off in the software, but at least that means it's getting spark and fuel (and the important part - megasquirt is getting a signal from the distributor).

This leaves me to follow some instructions on setting the 5V Vref signal.... and I think I'm going to do a modification of my own.... that is... the instructions (Megamanual) suggests using a 1k resistor between the 5V signal (there's a port directly on the board) and the Fidle.... well, the DIY kit came with a wire/resistor, and I already have a pin on 5V. So - I figure, Pin 6 I already rewired to the distributor 5v vref - so I may as well just use the jumper, install a pin on SPR4, then connect the pins from 5V to SPR4 - making it a simple solution.

 

[toyotaspeed90]

Super hardcore tip for the hardcore section.....

sometimes coils need a good ground, and your coil wires need to have a good connection.

Spent nearly an hour trying to figure out why it would crank and run with the starter, playing with timing, but wouldn't stay running. Clipped the ends of the coil wire boots (1/4" or so) and ran a ground to the coil, nearly jumped out of my skin when I hit the starter and it fired right up.