I've just started up my 1964 Tempest Custom. It runs!...sort of. I thought I'd start a tuning thread for this project since it would appear I'll need some help along the way and I'll be able to post the build specifics in this original post and then ask questions and hopefully get some help as I go without needing to re-post all the specifics. I'll also attach a current MSQ and any datalogs.
The Build:
-1964 Pontiac Tempest Custom
-1968 Pontiac 350 CID V8 (approx. 8.7:1 compression) bone stock (using this as a tuning mule to get the bugs worked out on the EFI programming / supercharger while building a very similar 400 CID with all the good parts to swap in later after the tuning learning curve.)
-Late 1950s Latham Axial Flow Supercharger
-Two Jenvey Heritage Throttle bodies. These each have two BOSCH EV14 https://store.jenvey.co.uk/throttle-bod ... r-tdp40-48
-The Jenvey Injectors were too small, so I swapped them for Bosch Injection EV14 Valve 0280158040
-Bosch T-Map Sensor 0 281 002 401 - Mounted in intake after supercharger (for intake pressure / temp)
-MS3Pro EVO
-Crank Sensor - Pertronix Hall Effect Sensor mounted in a 'locked' OEM distributor
-Ignition - single Bosch BIP373 triggering a single coil to supply hi-voltage to the distributor and out to each spark plug.
-O2 Sensor is the Innovate DLG-1 Dual Lambda Gauge (O2 Sensors mounted in dual exhaust per innovate manual)
-Exhaust 2.5" Pypes dual exhaust with X-pipe
-CLT GM Closed Element
-Fuel System is Radium Engineering - FST-R with Walbro GSS342 255lph pump. Fuel from tank is pumped via OEM mechanical pump to the surge tank, electric pump in tank pushes it to regulator, regulator set to 43.5 psig and supplies the four injectors, with the fuel pressure sensor being closely mounted to the injectors. A return line was added from the fuel surge tank to the main fuel tank in the back of the car.
-New plugs and wires installed.
-Lots more stuff went into this build but I believe this covers the scope from a digital / tuning perspective.
Current Issue:
I'm having trouble getting steady timing. Using a timing light I see 4-8 degrees of movement in the timing, I'm expecting 1-2 degrees of wiggle. I'm at the step in the manual that requires the "Fixed Timing" setting be selected and the "Trigger Wizard" be used to *calibrate* the timing signal the MS3 is outputting to the actual reading on the crank hub/timing mark. I can't tell if the jitter is coming from the pertronix (ie speed pickup has noise?) or perhaps the distributor rotor/rotor cap setup is not aligned enough for the spark to consistently end up being at the proper time. AFR is currently a little rich when running 10-12 (should be 14.7?) but it is backfiring at idle and any time I try to increase RPM above 1500 it begins to backfire. I did re-confirm firing order of the spark plugs and verified wires and I was recently in this engine and inspected the valves, timing chain, and pistons and know that they are workable.
Any help would be great - will attempt to post this with MSQ and data log of the crank trigger.
It seems as though the timing increases with RPM like 10-15 degrees of increase even when I have the setting of "fixed timing". I noted that the manual says that this could be caused by improper settings when using a VR/hall effect sensor so I double checked those, they seem as they should be. I due see a decent voltage increase with rpm as well, I'm wondering if the voltage regulator (stock 1960s style) is causing a problem. I'm still not quite understanding how to log data and get a graph that means something to me that I can use to spot issues. There seems to be some canned graphs but they don't show what I want and when I open the megalog viewer with my laptop's 4k screen its about useless, Impossible to navigate and figure out how to get a graph to show up, any tips? Thanks! - Thor
Did you shim the distributor to minimize the vertical endplay? I think you'd be happier and have less issues and a much more reliable set up using a crank wheel for the engine speed sensor. Nice to see another Pontiac with MS. Cool looking set up.
Lots of reading and research last night and I focused in on the voltage regulator. The voltage was very high and would swing higher with little RPM. The voltage regulator was an original 1960s AC delco style unit. So replaced that today with a new solid state one and now the voltage is rock solid on 12.5 volts when running. The timing is also much more solid only swaying 2-3 degrees which is about what a Pontiac typically sways due to a little slop in the cam to distributor gear and a little slop in the timing chain.
I set the timing to 12, mashed the "fixed timing" setting and with the engine running I adjusted the timing offset so that the '0' on the crank hub lined up with my 12 degree mark. The engine stills is back firing when over 1500 but I figure that is next, first step is solid timing. it seems less jumpy with the solid 12.50 volts. The timing still advances though even when it is set to fixed...
Next Issue: figuring out the VE table and ignition tables.
Scott65 wrote:Did you shim the distributor to minimize the vertical endplay? I think you'd be happier and have less issues and a much more reliable set up using a crank wheel for the engine speed sensor. Nice to see another Pontiac with MS. Cool looking set up.
No I haven't yet shimmed the distributor, but that's probably in order. Happy to find another MS-Pontiac as well. How is your ignition set up, curious if I chose poorly...
Mine is coil near plug using LS style coils. Here is a link to my build thread. Shows fairly good detail of how I did the crank and cam sensor set up and coil mounting. https://forums.maxperformanceinc.com/fo ... p?t=820018
Scott65 wrote:Mine is coil near plug using LS style coils. Here is a link to my build thread. Shows fairly good detail of how I did the crank and cam sensor set up and coil mounting. https://forums.maxperformanceinc.com/fo ... p?t=820018
Nice build thread! I took your advice the distributor was a little loose so I pulled it out and shimmed it, it now has the factory minimal slop in it.
I also found one issue and corrected it. The coil was a 1.5ohm pertronix one and it required like 8 ms dwell to get a junky spark, so i thought perhaps the longer dwell time was possible a part of the issue. I re-installed by original AC Delco coil and it runs a nice spark at 3 MS dwell.
Current status: I can get a great idle at 12 ignition advance and it runs around 12-13 AFR, but even when on "fixed timing" I'm still seeing a giant amount of advance come in when the RPM is increased from idle to 2000 rpm. I tried changing the "prediction" from "1st derivative" to "no prediction" no change. I've been trying different timing offset zones and it is currently running well at idle with a trigger offset of 47 degree and the base timing at 12 degrees advance. The voltage issue has been fixed and is now very steady at 12 volts.
Some thoughts on what could be causing the timing advance when the timing is set to "fixed"
1. Could there be electrical noise on the pertronix hall effect sensor that is causing the drift? How would I know/troubleshoot?
2. Could the MS3 be sending a varying timing signal and I'm just not seeing it? (I have a gauge "ignition advance" and on the gauge cluster tab and it mimics what I expect the output to the car should be, stays fixed at 12 degrees when I fix it, and matches the table when I point the ignition to "use table").
3. It is an 8 cylinder engine with a basic trigger (1 magnet goes past hall effect sensor for each spark event), the RPM seems to feel right (I know this car have had it almost 2 decades and the RPM signal matches my ears expected RPM) but could there be a math error somewhere or setting error that is increasing the advance output. I try to get the car warmed up and steady before messing with it just to make sure cold advance isn't coming into play.
Maybe include a regular log also. I have no experience controlling timing with MS on a distributor, but I notice that your trigger angle falls in between the areas that are recommended in the tool tip. (0-19 or 50-80 degrees) Maybe revisit the set up of the trigger angle to get it in the recommended area.
Have you tried swapping your input edge to falling and re-syncing the distributor?
When I converted the SBC in my dads 68 Poncho (don't ask...) to EFI, his distributor had a breakerless points conversion in it. It had the exact same timing wander with Rising Edge and fixed timing. The minute I set it to falling edge and set the trigger angle to 10 and turned the distributor to match the balancer, the timing was rock solid when fixed and would follow commanded when i reverted back to the table. See pic for the settings I used.
ECU was an MS2 v3.0 board, not entirely sure of the electrical differences between the EVO, but might be worth a try. The symptoms read similar to what I experienced.
Kris
PS, another Pontiac here
Attachments
2020-08-25_16-19-11-PonchoIgnition.jpg (307.09 KiB) Viewed 726 times
krisr wrote:Have you tried swapping your input edge to falling and re-syncing the distributor?
When I converted the SBC in my dads 68 Poncho (don't ask...) to EFI, his distributor had a breakerless points conversion in it. It had the exact same timing wander with Rising Edge and fixed timing. The minute I set it to falling edge and set the trigger angle to 10 and turned the distributor to match the balancer, the timing was rock solid when fixed and would follow commanded when i reverted back to the table. See pic for the settings I used.
ECU was an MS2 v3.0 board, not entirely sure of the electrical differences between the EVO, but might be worth a try. The symptoms read similar to what I experienced.
Kris
PS, another Pontiac here
Krisr, Thanks for the input and settings advice. I'll give that a shot. I'm glad to find another Pontiac on here!
Current Update:
I attempted to put an oscilloscope on the pertronix ignitor II output signal tonight and proceeded to mistakenly reverse the polarity and fried it. No more RPM sink. Took it out and ran through some tests and it was dead, nothing we did would show any feedback or get the car to run. I know the output side of the ignition is okay because we pulled a plug and put it in test and it fired the plug nice and bright. I ordered a new pertronix so when that shows up I'll get back into the troubleshooting. Maybe by chance the pertronix was in fact faulty out of the box and by chance the death of it may be a blessing as a new one might work? If not, I'll try the settings above and see if they work. Also, as noted by Kris, the timing offset angle is within the impermissible range, if I can adjust that a little I will which will probably mean physically indexing the pertronix pickup a few degrees in the distributor to move the offset angle out of the impermissible zone. I'll be able to make quick work of that modification. So, now wait for a Summit package...
Also, attempted to a megalog viewer from tonight's run before I fried pertronix. If someone might be so kind as to let me know if that is the type of log and in the format that is useful for this forum that would be helpful (Still trying to learn this system).
Update: New Pertronix installed. To be fair to Pertronix, the previous one was just fine, the pull up resistor had been yanked to hard during troubleshooting and had exposed bare wire with 12v and then found ground and blew the fuse (not a pertronix issue --- my bad). With new pertronix installed the car fires up and idles and I can get it to rev up a bit, but the timing still advances. My next step is to machine/adjust the location of the pertronix inside the distributor. When we hooked up an oscilloscope to the spark output signal and the pertronix signal you could see the size of them changing with RPM and you could set the signal translating separately. As per the MS3 EVO Manual, the trigger offset angle needs to be in a certain range to work with basic trigger. Right now, it appears the MS3 is looking at a magnet flying past the hall effect sensor and using that to trigger a spark quite a few degrees later, I want to aim more for the 0-10 degrees of offset from BTDC which is going to require some mods inside the distributor.
I did try changing the falling edge/rising edge, going low, going high settings and I could see a change in the way the advance reacted but it still advanced on "fixed timing".
Some Progress. I removed the distributor gutting an old vacuum advance mechanism, replacing the diaphragm with a slotted plate that I can adjust from outside the distributor while the car is running that moves the hall effect senor about the axis of the distributor. In this way I was able to mechanically adjust the hall effect sensor while the car was running to get it to align with the trigger angle offset of 10 and a fixed timing single of 12. This worked great and will be a huge help in the future as offsets and base timing needs adjusting or changes. I fired the car up and it ran the same with a jittery timing and it would advance with RPM. I read up on and began to add noise filtering and got the timing signal to be very smooth. It still sways with RPM. I started playing with the dwell and noticed it had a profound impact on timing. So I did some reading on the pertronix ignitor II and it actually says in the advertising:
Adaptive dwell maintains peak energy throughout the entire RPM range
Compensates for inherent electronic delay by adjusting the spark timing throughout the entire RPM range
So I'm not sure that that isn't the problem and either the dwell or the pertronix's spark timing adjustment isn't the problem. So I read up on the Pertronix Ignitor (PN 1181) and it seems much dumber and the advertising says nothing about timing adjustments or changes to dwell. So I ordered one and it will be here tomorrow and we'll see what happens on friday.
I also played with the going low/falling edge settings and am currently running that way, I do want to swap back to rising edge going high when I get the new pertronix 1181, I do think that looking for the front edge of the magnet makes more sense but at this point I'll take what works.
I suspect that the Pertronix's rising edge (when it fires the coil) will give a more stable signal; this is usually inverted by the ECU to trigger on falling edge. However, I haven't tested if the signal where it starts the dwell is stable or not. If the module is actively controlling the dwell, it won't be. I get the impression the Ignitor 1 does not control dwell but the Ignitor 2 does; however, this is something I inferred from the fact that the Ignitor 1 uses a ballast resistor rather than being certain from their spec sheets.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Problem Solved: Pertronix Ignitor II varies the dwell which causes the timing to float. I switched the the ignitor II out for an Ignitor I and it now has perfectly steady timing. I did switch it back to Rising Edge and Going High and got a very nice signal, steady timing when on Fixed Timing and actually saw a very slight retardation of timing as RPM increased which I will tune out using the hardware latency setting in the startup/ignition settings. I highly recommend to anyone that comes along and follows this pertronix path to use ignitor I and when you "fix" the distributor, fabricate an adjustable slide on it where the vacuum advance used to be so you can use the Trigger Wizard to set timing to 0 btdc and then mechanically adjust the hall effect sensor (pertronix ignitor) to match that on the timing marks, it is so easy to set the timing now.
After overcoming the crank trigger signal, I set the timing to Use Table with a conservative table I built using some original Pontiac timing curves and some articles on this supercharger and was off to the races. I have a conservative VE table as well. I took the car out for a ride and have begun tuning the table. One open ended question in regards to MS3 that I have in the moment, I'm sure I'll have hundreds more, is where to find good pulsewidth and dead time data on Bosch EV14 0280158040 injectors. I was playing around with that and noticed it has a huge impact on the numbers in the VE table and, as the manual says, should be accurate and set up front before too much tuning. Any pointers on this data would be great.
Thanks for all of your help on the crank trigger timing issue, I am very pleased that is behind me and I can drive the car. I did run into a very slow overheating issue but that isn't MS3 related it has to do with the mechanical setup of the fan which I'll work on getting sorted. I also need to go shorten the belt a bit.
Tuning is going well, I keep getting more and more comfortable with each trip. I keep slowly adjusting fuel and smoothing the table and each trip I get into a newer area of the table and see how it does. I think I need to adjust the advance table, I think its not coming in fast enough and I don't think I have enough initial timing. I'm comparing how the timing line reacts with a Stock Pontiac GTO Tri-power that has mechanical advance and a vacuum advance module against my table and my table seems to be quite conservative and doesn't advance nearly enough. I have yet to hear or run into any pinging. Any of you Pontiac guys that have none boosted or boosted Pontiacs that may have an opinion on my table and how it might compare to yours would help me with a sanity check.
Picture of table attached - for now I'm just trying to get the 0 kpa to 100 kpa to match a stock distributor and will adjust in the boosted zone later.
Timing Table 9720 Tempest.PNG (240.13 KiB) Viewed 533 times
This is what my 400 looks like on gasoline with Edelbrock heads (bathtub chambers) on gasoline. The E85 table is only slightly more aggressive. The biggest difference though is i'm running a healthy solid roller on 108LSA installed at 106 I think I put it, or was it 104? somewhere around there regardless. Idles at 1000 @ 80kpa, no issues with brakes, acceleration, return to idle etc..
2020-09-08_11-41-38.jpg (677.89 KiB) Viewed 529 times
