HEI ignition issues

[Rickster]

Hi all,
Previously I was having some issues getting my engine setup with base timing & getting the engine to run with the computer controlling the ignition.

I discovered that a good part of my base timing issues was a bad timing light. I borrowed one of my mechanic friends high dollar unit and I was able to dial in the base timing with the computer control wire disconnected. I used 10 degrees as base timing. I was able to play with the ignition settings and I got the engine to stay running withe computer control wire plugged in. Once the wire is plugged into the ECU (bullet connector in the engine compartment) the engine runs, but the timing indicator is jumpy as viewed with a timing light. Also the engine misses every once in awhile (approx once every 2-3 seconds), and it is also evidenced by the timing strobe not firing (missing a beat) when this happens. I have my timing table flattened out to 10 degrees as recommended in a video I saw (DIYautotune).

The issue now is that the computer does not seem to really have any effect on the timing. If I set all the values in the ignition table to 15 degrees, the timing light does not show a difference. The engine will change RPM, then settle back to where it was when I make the table change in TS, but the actual timing (as seen by the light) does not change.

This is a MS2/extra built per instructions on this site for a GM HEI 8 pin module.

Since (I believe) the HEI circuit as provided by this site (http://www.msextra.com/doc/ms2extra/MS2-Extra_HEI.htm) uses the HALL sensor (but the actual pickup appears to be a VR?) The adjustable resistors will have no effect correct?

Chevy 350 using an Mallory small cap HEI marine distributor (yle624A), MSD 4pin coil. The Mallory distributors use their own pickup, and do not use the GM style pickup (see attached image).
I have since replaced the original Mallory HEI module with a Bosch unit because I was afraid it was causing issues earlier in the build.

I am attaching a trigger log, tune file and idle log.

[jsmcortina]

There's no need to set the whole timing table to some single number, use the "Fixed timing" option - that's what it is for.

How is you EST connection wired? Lack of timing control is most frequently caused by miswiring or wiring not matching settings. You are set as "D14" as the spark output - is this where you have yours connected?

James

[Rickster]

I used the fixed timing option first, but it was not working so I set the table that way just to be sure after exporting the original table.

I used the board modifications found here under the heading "Internal Mods for V3.0 PCB's":
http://www.msextra.com/doc/ms2extra/MS2-Extra_HEI.htm.

I have absolutely no other mods done to the board, other than the options I needed to choose during the basic assembly process and IAC stepper motor jumpers.

You can inspect my D14 & D16 connections here:
http://98.238.246.71/MegaSquirt/New%20M ... G_3136.jpg
http://98.238.246.71/MegaSquirt/New%20M ... G_3137.jpg
I have fixed an old wiring mistake were I had D14 wired to IGBTOUT instead of IGN (indicated in image)

D1 & D2 are empty.

PIN # Connection
1 Coolant Temp Ground
2 Air Temp Ground
3 N/A
4 N/A
5 N/A
6 SpkB (pin "B" on HEI 4 pin connector) pin second from left
7 HEI Ground (pin "G" on HEI 4 pin connector) pin first from left
8 Shielded Cable Ground
9 TPS Ground
10 N/A
11 N/A
12 N/A
13 N/A
14 Ground
15 Ground
16 Ground
17 Ground
18 Ground
19 Ground

20 Air Temp
21 Coolant Temp
22 TPS
23 O2 Sensor Signal
24 Pickup Signal (pin "R" on HEI 4 pin connector) pin third from left
25 IAC 1A With "mushroom" on top pin#1
26 TPS (5v refrence)
27 IAC 1B With "mushroom" on top pin#2
28 Power to Megasquirt From 3 AMP fuse
29 IAC 2A With "mushroom" on top pin#4
30 N/A
31 IAC 2B With "mushroom" on top pin#3
32 INJ 1
33 INJ 1
34 INJ 2
35 INJ 2
36 SpkA (pin "E" on HEI 4 pin connector) pin fourth from left
37 Fuel pump relay ground

I did apply some extra heat to all of the smaller transistors using solder wick (backside of board) to make sure I had no bridges on any of them. Is there a way to test them on the board?

And a question...In the extra ignition options, is toggling "GM Bypass on D16" the same as connecting and dis-connecting the ignition ECU control wire (pin 6)?

Thanks,

Rick

[Rickster]

I played some more with this today. I have some odd repeatable results that I could really use some input on.

With the engine warmed up, fixed timing set to 15 degrees in TS trying to get my trigger offset correct:

1. Shut off the engine, then start. Rough idle, I can physically see the strobe on the timing light while sitting on my stool at the TS console. It is skipping a beat or 2 every second. It is not skipping in a predictable fashion. The timing mark on the pointer is jumping around by about 5-6 degrees as viewed by the timing light.
2. With the engine running, using the trigger wizard, I click the + button about 2-3 times while watching the timing light. The strobe now fires smoothly, the engine no longer misses and the timing mark is very steady on the timing pointer.
3. I hit the BURN button. The engine goes back to missing again, and the strobe is erratic once again. I can repeat this over and over. Its smooth and reacts to my trigger changes, but once I hit burn it is messed up again. Eventually I have to set the offset back to something low like 12, and creep up on it again because the offset gets too high.

I have full logs, tunes, etc attached to my first post.

Also, I am assuming that I don't need to make these connections? (http://www.msextra.com/doc/ms2extra/MS2 ... .htm#1coil) because the single external coil is driven by the HEI unit...

I would be happy to give someone my email address if you would like to help one on one?

Would someone please take the time to look this over??

Thanks

[Rickster]

Could someone also please explain this to me?

FROM the HEI module page http://www.msextra.com/doc/ms2extra/MS2-Extra_HEI.htm

3. Whichever terminal the rotor is pointing at is now cylinder #1. The rotor should be much closer to one terminal than the others (it wil probably have gone by one of the cylinder's terminal by a bit, that's okay - it means it will line up with a bit of advance - you can rotate the engine through very nearly two complete revolutions to check - get it to about 25° to 30° BTDC and it should align with the terminal). If the rotor is pointing between cylinders (i.e., the phasing is off), then it's likely that the distributor is off by one or more teeth at the camshaft (in a V8 HEI install, at least). On a small block Chevrolet, for example, the distributor should be installed so that the rotor is pointing a little in front of the #1 cylinder when the engine is at TDC on the compression stroke for cylinder #1 - all other positions will create phasing problems.

How in the world could "Phasing" be off?

The rotor and pickup sensor vanes are mechanically tied to each other. Likewise the pickup and pin towers are mechanically fixed to each other. I don't understand how it could possibly be setup "one tooth off"??? What ever pin the rotor is pointing at when the #1 piston is at TDC is pin one...rotating the engine over twice will always place the rotor in the same position it started in?

Am I missing something here?? I mean if you rotated the engine twice from where you started and it comes to a different place on the rotor, then it isn't a 4 stroke engine...
Instead of it being a tooth off, you really just don't have your sensor aligned correctly (ie distributor twisted to the correct general position to align the vanes and pin 1)?

Here is an image of the inside of my distributor: http://98.238.246.71/MegaSquirt/distributor/2.JPG

Thanks

[jsmcortina]

I don't know what's going wrong here presently. I do know that there have been many HEI installs already that do work.

James

[Rickster]

Has anyone here done a successful 8 pin HEI module install? I see many 7 pin, but any 8 pin?

Also, this is not a factory GM distributor, but a Mallory unit that uses a different pickup than the factory unit. Would that possibly change things? I would think that because the pickup plugs into the HEI module, and it in turn controls the spark, that it would be setup the same as a factory unit?

I'm starting to think that at this point I might just go fuel only and use my other stand alone Large body HEI unit (Hypertech) that I replaced. Problem is that I will now need to go back and re-work the board for that.

[ChevelleFan]

I had a successfully working 8-pin HEI setup. I had the 'C' wire on the 2-pin HEI terminal hooked to the white wire of my MSD box, so the MSD box took care of the direct coil control (ie, didnt have to worry about dwell settings). But the B-pin and E-pin (2nd and 4th terminals, respectively, on the HEI) were controlled by MS, with the R-pin providing tach signal to MS.

Hard to say about your distributor. I googled it real quick and seems to be a direct replacement for the 8pin distributor. Do you have access to a factory GM distributor? Might be worth a shot. I struggled with my install initially. I swapped distributors and then everything worked as it should. Both my units were used and I didn't know their history.

You mentioned possibly running your large cap HEI instead and doing fuel-only. I did that on my first install to ease the learning curve. This at least lets you get the car running and the fuel side somewhat dialed in.

Here's an MSQ that I'm pretty sure worked fine for me, MS2-Extra 2.1.0d, I think.

[Rickster]

Thanks for your input Tony, I really appreciate the info.

I'm at my wits end trying to get just the basic ignition stuff working. I have built several motors in the past and I have to say this has been/is the most frustrating problem I have ever dealt with (motor wise).

I really enjoy building stuff myself and thought this would be fun. I'm past the fun part now.

[ChevelleFan]

Thanks for your input Tony, I really appreciate the info.

I'm at my wits end trying to get just the basic ignition stuff working. I have built several motors in the past and I have to say this has been/is the most frustrating problem I have ever dealt with (motor wise).

I really enjoy building stuff myself and thought this would be fun. I'm past the fun part now.

I've been in your exact same situation, believe me! I had a lot of troubles getting the ignition parts going for whatever reason too, but once it worked, it worked. I'll try to help you out here.

To try and address a couple of your questions -- I don't think the phasing can be off, as you said. Set the motor to 10-20* BTDC, stab the distributor in, line up the VR pickup points in the distributor, and wherever the rotor is pointing is now #1. I usually try to make it similar to factory -- If standing at the front of the car, the typical #1 terminal would be about 5-oclock on the distributor.

Also, I am assuming that I don't need to make these connections? (http://www.msextra.com/doc/ms2extra/MS2 ... .htm#1coil) because the single external coil is driven by the HEI unit...

Right -- follow the HEI instructions, not single coil instructions. Having said that, in my situation, I use an MSD 6AL to actually drive the coil. I have the HEI C-terminal connected to the white wire on the MSD.

On your HEI module, what are you connecting the B-terminal to? MSExtra2 manual says to go to D16. But for some reason, on start up, D16 doesn't get activated until the engine is in Run mode for 5-seconds. I don't know if doing a burn affects/triggers this behavior, so it might be something to keep in mind. I know my engine runs kinda crappy during those first 5-seconds of startup. DIYAutotune, in one of their articles, wired the B-terminal to TPS VREF, so that the distributor was getting/using timing advance signal immediately from MS. I haven't personally tried this, but I'm going to when I get my car back together in the next few weeks.

I don't have TunerStudio on this machine, but I'll try to take a look at your MSQ sometime today to see if I see anything obvious.

-Dave (Tony is my friend, whose motor I was using at the time)

[jsmcortina]

On your HEI module, what are you connecting the B-terminal to? MSExtra2 manual says to go to D16. But for some reason, on start up, D16 doesn't get activated until the engine is in Run mode for 5-seconds]

That is by design to match what GM does in their vehicles it should give stable timing during cranking at the "base" advance.
Check your timing with B unplugged.

James

[ChevelleFan]

On your HEI module, what are you connecting the B-terminal to? MSExtra2 manual says to go to D16. But for some reason, on start up, D16 doesn't get activated until the engine is in Run mode for 5-seconds]

That is by design to match what GM does in their vehicles it should give stable timing during cranking at the "base" advance.
Check your timing with B unplugged.

James

Hi James, I probably should've been more explicit, as I've seen your explanation on that before. I just know that on my engine, it runs junky that first 5 seconds because my base timing was only 10-15*, but my true desired idle timing is more like 28-30*. I have a bone-stock '94 Chevy 5.0 truck, which is a factory 8pin HEI, and don't notice any discernible change in the engine like that on startup. I've never put a timing light on there to confirm, though.

I was surprised to see DIYAutotune mention hooking the B-terminal to TPS-VREF in one of their articles, http://www.diyautotune.com/tech_article ... 2-nova.htm. I think it will help out my own issue and thought it could be an alternative for the original poster, Rickster. If it works, I think my engine will run better, -- and that's the whole point of this, right?

Rick, in comparing my MSQ to yours, I see differences on the "More Ignition Settings" dialog, and the Noise Filtering dialog. Check my settings. Also, I see you have your ignition table flat, at 10* everywhere. I presume you're doing this for testing. Once you get it working, try my spark table as a starting point.

I looked at your log and I can see the engine idling, TPS never moves, KPA between 44-47, rpm 950-1200, and the advance is always 11* -- not sure why 11* and not 10* like your table.. I'm not an expert. Even just for testing, I would just bump your table to 20*

Describe the rest of your engine/car setup. Where are you located?

-Dave

[Rickster]

Thanks for your input Tony, I really appreciate the info.

I'm at my wits end trying to get just the basic ignition stuff working. I have built several motors in the past and I have to say this has been/is the most frustrating problem I have ever dealt with (motor wise).

I really enjoy building stuff myself and thought this would be fun. I'm past the fun part now.

I've been in your exact same situation, believe me! I had a lot of troubles getting the ignition parts going for whatever reason too, but once it worked, it worked. I'll try to help you out here.

To try and address a couple of your questions -- I don't think the phasing can be off, as you said. Set the motor to 10-20* BTDC, stab the distributor in, line up the VR pickup points in the distributor, and wherever the rotor is pointing is now #1. I usually try to make it similar to factory -- If standing at the front of the car, the typical #1 terminal would be about 5-oclock on the distributor.

Also, I am assuming that I don't need to make these connections? (http://www.msextra.com/doc/ms2extra/MS2 ... .htm#1coil) because the single external coil is driven by the HEI unit...

Right -- follow the HEI instructions, not single coil instructions. Having said that, in my situation, I use an MSD 6AL to actually drive the coil. I have the HEI C-terminal connected to the white wire on the MSD.

On your HEI module, what are you connecting the B-terminal to? MSExtra2 manual says to go to D16. But for some reason, on start up, D16 doesn't get activated until the engine is in Run mode for 5-seconds. I don't know if doing a burn affects/triggers this behavior, so it might be something to keep in mind. I know my engine runs kinda crappy during those first 5-seconds of startup. DIYAutotune, in one of their articles, wired the B-terminal to TPS VREF, so that the distributor was getting/using timing advance signal immediately from MS. I haven't personally tried this, but I'm going to when I get my car back together in the next few weeks.

I don't have TunerStudio on this machine, but I'll try to take a look at your MSQ sometime today to see if I see anything obvious.

-Dave (Tony is my friend, whose motor I was using at the time)

Thanks Dave for the input.

Thanks for clarifying the phasing question. I was pretty sure you couldn't get that messed up, but I was starting to doubt myself. It is installed in the factory position with the rotor pointing just before cylinder #1 at TDC on the compression stroke. I have the distributor body rotated so that the plugs point to the passenger side fender.

The "B" terminal is connected to pin #6 of the DB 37. I assume that by following the instructions on this site for the MS2/Extra v3 board that this connects in turn to D16? The instructions had me wire a 1K resistor from the 5v proto area to the -ve side of D16, then a wire from the ve side of the resistor to SPR4. Does SPR4 = pin #6?

I am going to go through the rest of your suggestions and see what I come up with

Thanks!

[Rickster]

I tried using the 5v ref from the TPS.
Before starting I verified that the recommended pin # 6 was functioning properly. When the key was off = 0volts, until 5 seconds after start it was zero volts and then it switched to 4.2 volts (this should be 5v?)

Then I found the 5v reference line for the TPS and verified I had the right one with a voltmeter. 4.89v key on, 0v key off, no movement with throttle position change.

When I connected the 5v from the TPS to pin "B" (second pin from the left on the HEI connector) the engine would not start. I have the air clearner off so that I can see the injectors fire. There was very little injector activity. I switched the pins back (B to pin 6) and it fired right up with strong injector activity.

So, it appears that wiring the "B" wire of the HEI module to the TPS 5v ref line is doing more than just sending a 5 volt signal to the HEI?

Should I just package this up and send it to DIY for diagnostics and possible repair?

When DIY tests a board is every single component tested, or is it just a spot check of critical components? Can I be assured that the ECU coming back is 100%?

Thanks all.

[ChevelleFan]

Sounds like you've been pretty methodical about it.

When you have B-terminal wired up per the Extra Manual (pin 6) and it starts like you say, where is the timing?

I don't think you have a bad MS. DIYAutotune is a pretty reputable supplier, maybe even the biggest? You should have no worries with those guys. If you can get Matt Cramer to look at this thread (try sending him a PM?) , maybe he can make a suggestion before sending it in.

-Dave

[Rickster]

I have base timing set to 10 degrees. I have also tried 0, 15 and 20. None of them make any difference.

Just for a re-cap, the issue is that I cannot get the computer to actually control the timing. Once I set base timing with the "B" pin disconnected, then reconnect the "B" pin, I cannot get trigger wizard to set the angle correctly, and when the ignition displayed in TS changes, the timing at the light does not change.

For example, when I rev the engine slightly the timing display rises in TS but it stays the same (decreases by a few degrees actually) on the light.

I will send Matt a PM in the morning.

Thanks again for the extra set of eyes.

[Matt Cramer]

If the engine runs with 5 volts on the "B" pin but the timing won't adjust, I would suspect the HEI module and not the MegaSquirt.

[Rickster]

I did too, its a new module.
-=8-)

New pick up as well. And I bought the distributor new.
The only thing used is the Throttle body, and plug wires. But it idles just fine, so I figure those are OK. I have not seen any arcing from the plug wires in the dark either.

As a test I also bypassed some of the old wiring between the ECU & coil. That made no difference either.

Rick

[Matt Cramer]

New is not always the same thing as good.

[Rickster]

I changed out the HEI module to a new Bosh unit and I still get the same results.

Thanks,

Rick