Toyota 20R/22R GM H.E.I. Ignition Module Conversion - Extra Info 

Glad to be of help. Just passing along the info & knowledge I've gained to help others out. BTW & I don't recall if I mentioned it in this update video, but you can run this without the ballast resistor, IF you use a Standard Motor Products UC 15 Ignition Coil instead of the UC12. The UC15 is internally resisted so it doesn't need the external ballast resistor, where the UC12 isn't internally resisted, so it needs the external ballast resistor. Just wanted to get that info posted here for others to see.

Thank you watching & for the kind words. I do need to tell you though that I have discovered a small but vital point as concerns the choice of ignition coil, which I will be making a separate video of soon. That point is, if you decide to go with an original type of coil specified for the 20R, you're going to need to also wire in a ballast resistor on the RUN side of the circuit, & also wire up your starters "R" terminal to the coil's + post. Ignition coils designed for the 20R may be marked as "12 volt", but I have found that they do not perform well or last too long running constant battery voltage (typically 13.5 volts). They are actually designed to run on 8-9 volts, & only get full battery voltage from the starter R terminal at start-up. This was true up until 1980 models. Even though the 1978 to 1980 models has the electronic igniter instead of points, they also had ballast resistors. Even with a new coil (Standard UC12), the idle run quality is mildly inconsistent, & the coil started to develop hot start issues within 3000 miles. I added a 1.4 ohm ballast resistor (Standard RU-4) with another new coil (also UC12) & the difference in idle & run quality is *Very* much improved. Of course you could choose a 1981 or newer "brick" style epoxy-filled coil specified for the 22R & not need the ballast resistor. Those later coils were designed to work at full running battery voltage at all times. They also have the added advantage of a lower Primary resistance plus a higher Secondary resistance over the older style coils, so you'd get even better spark at the plugs. Just wanted to get this out there for you or for anyone else reading these comment threads. If I can help with any other info just let me know.

Understood, can I pick your brain and ask what wire gauge would you use

@@phillipferrer4668 Of course you can. I recommend a minimum of 16 gauge stranded wire for creating your wire hookups, with 14 gauge being better IMO. 16 gauge will safely handle up to 10 amps while 14 gauge will safely handle up to 15 amps. While the module itself will certainly never draw more than 2-3 amps, the coil could be a different story, depending on coil choice. The older style coils that are designed to use a ballast resistor (like the Standard UC12 that I used) draw 3-4 amps. But the later "brick" style coils can draw up to 8 amps. That's why the difference in wire gauges. I like to have a safety margin of 2X to 3X in my circuits, to prevent overheating & damage to the wiring or components. No one needs to start an engine compartment fire that way. 😬 I also recommend that connectors be soldered onto the wire if possible, instead of crimping them on, unless you have a proper crimp connector tool to use. In either case I also shrink tube all terminal to wire connections.

Thank you for the kind words. I noticed the problems you mentioned as well, which I why I wanted to make the video(s) as complete & direct as possible. The only reason the factory GM system has the capacitor in the wiring is for radio noise suppression. RF (radio frequency) noise can be produced by the ignition system operating, often experienced as a fluctuating "whining" noise that can be heard through the speaker(s). It can also come from the old-fashioned generators & sometimes from alternators, but most of those units came with a capacitor (also known as a "condenser") pre-installed on the unit(s). While capacitors store electrical energy, they also act as a "voltage smoothing" device. The noise interference you may hear are actually changes in voltage frequency. The capacitor "smooths out" those changes so they are reduced or eliminated. There is also a capacitor in your fuel gauge circuit that also does this. It prevents the fuel gauge needle from bouncing around every time the float on your fuel sender moves. You should install one if you are experiencing radio noise interference, even with the HEI conversion installed. I never did it because the late 80's - early 90s vintage AM/FM/cassette radio in my truck has never worked, so it's not an issue for me. For more info on this I recommend the following: www.howacarworks.com/accessories/identifying-and-suppressing-radio-interference BTW you don't need to get or use the "factory" HEI wire bundle with the capacitor in it. Any standard capacitor/condenser intended for auto application that is rated at 0.5 to 1 microfarad (MFD) & at least 100 volts will work. See the article I referenced above for more info. Thanks again for the most kind words & let me know if I can be of any help in the future.

Thank you. It could also possibly be done on any 22R carbureted engine up to the 1995 model year, as the same type of distributor was used until then.

@@The13thSword thanks my friend

I'm glad that the vids & info have been of help to you. I will try to take your points & questions in order. I have done quite a bit of research on these modules and the differences in brands. It is my opinion that the Delphi module is just as good in quality (if not better) than the AC Delco module. These days the AC Delco is made in China, while to the best of my knowledge the Delphi modules are still US made. I would seriously doubt that a Delphi module would be defective right out of the box. The fact that you wired it up & it works right off the bat pretty much tells me it's not the module. It is possible that it's become damaged since you installed it but that another thing I'll address later. What ignition coil are you using, brand & part number? I've learned that the original style coil (like the Standard UC12 coil) doesn't do so well with the HEI module unless you use a ballast resistor. The secondary side of the coil tends to get "cooked" at full battery voltage & when that happens, it can damage the module. If it were me, I'd resistance test the coil first with an Ohm meter to check for high resistance in the secondary side of the coil. The original coil specs are 1.3 to 1.7 Ohms Primary (test leads on + & - terminals) & 6500 to 10,500 Ohms Secondary (one test lead on center terminal, other lead on either + or - terminal, doesn't matter which one). Test should be done "cold"; after the engine hasn't been run for at least an hour. Anything higher than 9250 Ohms on the Secondary means the coil is either going bad or is bad. More on coils later. Gaps - Good work on verifying the air gap on the Pickup Coil. Spark Plug gap should be set to stock at 0.031" or 0.8mm to work the best with this setup. Larger plug gaps will not be beneficial. Also (being a bit redundant here (don't take it personal), *NEVER* trust the "factory gap" on spark plugs right out of the box. Always check & set them yourself before installing. What brand & part #'s of plugs & wires are you using? Did you also replace the cap & rotor with new? Distributor/Engine Timing - Correct stock setting is 8 degrees before top dead center (BTDC). This is with the engine fully warmed up, choke fully open, idle speed set correctly (800 RPM for automatic trans, 850 for manual trans) & vacuum advance line disconnected from vacuum advance. The vacuum line needs to be plugged to prevent a vacuum leak (I use a golf tee or a nail of the appropriate size for this). Speaking of distributors..... Are you running the original distributor? If yes, how many miles are on the vehicle? High RPM cutout like you describe can be due to a worn distributor, or more likely a sticky advance mechanism or missing weight springs. Those need a bit of lubrication for time to time on the pivot points for the weights. If the mechanism doesn't "advance" on higher RPM's you could experience the symptoms you're describing here. You could also have a vacuum leak in the line going from the carb to the advance unit, or possibly have the line hooked up to the wrong port on the carb so that the advance unit isn't getting the proper vacuum "signal" at the right time(s). If all of those things check out OK, I'd than suspect that you have a fuel issue, either with fuel delivery or am internal carb issue, or possibly a large vacuum leak somewhere. Is the carb original? Has it ever been rebuilt? While the engine is running/idling have you ever sprayed the carb with carb cleaner to see if it rises in RPM's? That's a good way to find hidden vacuum leaks. There's tons more small or other things I could mention but I think I've given you enough to look at & think about. More often than not with these trucks it's something simple & usually related to age & use. Let me know the answers to those questions & what you find out.

That well could be. When you're "bench testing" this system on the dining room table, are you also grounding the spark plugs? They usually ground to battery negative through the cylinder head via the engine block, motor mount, frame, and battery negative ground cable. But with bench testing, you have to supply a ground for the spark plugs, as none of that side of the circuit is there. You'd also need a direct ground from battery negative to the grounding tab on the HEI module. A "high energy coil" really doesn't make that much difference in normal driving performance, and would just cost you extra $. If your old coil is testing out OK on the Ohm meter (in spec) it's likely not the issue. Correct spec for the '75 to '79 stock coil is 1.3 to 1.7 Ohms Primary, and 6500 to 10,500 Ohms Secondary. These are "cold" readings, meaning the coil hasn't been recently exposed to running conditions or had battery voltage applied to it for at least an hour. If the Secondary spec reads anything over 9400 Ohms the coil is weak & needs to be replaced. For the HEI conversion I highly recommend using the Standard Motor Parts coil UC15. It's internally resisted so it doesn't require an external ballast resistor**. Much simpler. If you have any questions about the above or anything else about this conversion just ask. And please let me know what happens if you do put this system in the truck. ** PS - The original stock '76 20R contact points distributor ignition system had a ballast resistor in the "+" side of the circuit. It was there to protect & lengthen the useful life of the contact points. Your original '76 coil will need to have the ballast resistor on the "+" side of the power feed to the coil, as the coil was designed to function that way. Eliminating the ballast resistor & running the stock coil on full battery voltage will "burn out" the stock coil in short order. If you've done your "bench testing" without the ballast resistor in circuit, it could have caused an issue with the coil's Secondary. Retest it with your Ohm meter to be sure. I've learned about this the hard way & have more info on that detail alone; just ask if you need/want to know more.

I have not noticed any differences in starting time or fuel consumption. In fact my miles-per-gallon is exactly the same as it was before with the Toyota Igniter ignition module. I would suspect that your carburetor could do with a little cleaning and tuning, if those things haven't been done for some time. Sticking linkages, cables, and/or idle mixture set incorrectly can cause intermittent starting delays/problems. For exterior cleaning you do not have to remove the carburetor from the engine. Use carburetor spray cleaner on all of the exterior moving parts (linkages) to remove any substances that may be making the linkages stick & not able to move freely. You may want to put some cardboard or paper around the base of the carb before spraying to catch any "junk" & keep it off your your engine. Once the carb cleaner has completely dried, it's a good idea to lubricate all of the moving points on the linkages with a light machine oil, mineral oil or ATF (Automatic Transmission Fluid). Don't over-do this, just use enough lubricant to lubricate a moving point or pivot point, or any moving parts that contact each other. Chain & Cable Lube also works well for this (see next paragraph.) It is also possible that your throttle cable is sticking sometimes due to lack of lubrication or wear. It is 29 years old. To lubricate it you'll need a cable lubricator tool. More info here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-aQnMdOL09uY.html DO NOT USE WD-40 as cable lube. The solvents in it can melt the plastic sheathing of the cable. I recommend PB Blaster Chain & Cable spray lube. Next you will want to adjust the idle mixture screw. This is done with the engine fully warmed up to operating temperature and with the choke fully open, and with the engine running at low idle speed (750 RPM for Manual Transmission, 850 RPM for Automatic Transmission). The idle mixture screw may or may not have a plastic cap or plug over it; if yours has the plastic cap/plug it needs to be removed to access the idle mixture screw. The Idle Mixture Screw is located at the middle base of the carb on the right side of the vehicle. Picture of screw location(s) here: www.yotatech.com/forums/f2/carb-adjustment-48857/#&gid=1&pid=1 If the engine is already running fairly smoothly, slowly turn the screw to the left until the engine just starts to run a little roughly, then turn the screw slowly back to the right until the engine runs it's smoothest. This should take 1/4 to 1/2 of a turn. If the engine already runs a little rough (or more), you will have to try turning the screw in each direction & listen to how the engine runs and responds, until you find the correct setting where the engine runs it's smoothest. After doing this adjustment you may have to adjust the warm idle speed screw (see picture) to get the correct warm idle speed. It would also be a good idea to check for vacuum leaks in any hoses going to the carb, & to check that your engine timing is set correctly. 5 degrees BTDC (before top dead center). I hope this helps. If you have any other questions just ask.

I already answered your direct email on this but will also answer here. The Cardone 31721 is correct. Not sure what's going on with that unit having a brown and a tan wire, but there is a way to figure out which one is supposed to be the "red" wire and which one is the "white" wire. Take the cap and rotor off the distributor if you haven't already done so. Look inside the top of the distributor and locate the pickup coil that has the two wires coming out of it. It will look like this: www.rockauto.com/en/moreinfo.php?pk=28291&cc=1275982&pt=7108&jsn=9 Notice that the two wires are "stacked", top and bottom. The bottom wire will always be the "red" wire & the top wire will always be the "white" wire. Just pick one wire and visually follow it to the plug end. Then you'll know which terminal in the plug is which. Also, you said in your email that you have a stock Igniter system in that '77 Rona. There should be a rectangular plug coming off that unit that should directly connect with that Cardone distributor. Those rectangular plugs can only be connected in one way, because of their design. So there shouldn't be any way to connect the two things out of phase or backwards. Have at look at your plugs & you should see what I mean. As long as that stock Igniter unit is from "78 to '80 they should fit. If the plug on the Igniter is round instead of rectangular, the Igniter unit is an '81 & newer unit. That can still work but you'd also need to obtain or fabricate a jumper wire with female spade lugs at each end to connect the two items together. I don't have a source for the stock Toyota plugs. As I said in my email, any specific questions just ask.

The HEI Module modification will work even better with the later style rectangular ignition coils. This is due to the fact that the rectangular coils have a much lower Primary resistance than the older style "can" coils, on the order of 50% less. Secondary resistance specs are pretty much the same. The rectangular coil will actually put out more voltage on the Secondary side than the "can" style coil. The 4 pin HEI module system was originally designed to work with an epoxy-filled rectangular coil with resistance specs of Primary 0.2 - 0.8 Ohm & Secondary 5000 - 11,000 Ohms. This is very similar to your stock 1982 Toyota "Type III" coil specs (Primary 0.8 - 1.0 Ohm, Secondary 7000 - 13,000 Ohms. So the short answer is yes, your stock Toyota coil should work fine with the 4 pin HEI module. They are very compatible. That also means your stock spark plugs, plug wires & plug gap spec should work without modification. Toyota's stock Reluctor gap spec is 0.008" - 0.016" (0.2mm - 0.4mm). I have mine set right in the middle at 0.012" (0.3mm) & it triggers the HEI module with no issues. No epoxy-filled rectangular style ignition coil that I am aware of requires a resistor. Most of the old oil-filled "can" style coils needed am external resistor to keep it from having too short of a service life from overheating & failing. There are a few "can type" coils that don't need an external resistor, but either type is almost always clearly marked on the outside of the "can" which type they are. Reference: www.rockauto.com/en/moreinfo.php?pk=47707&cc=0&pt=7060&jsn=3 In your case, no external resistor is required. As usual with this mod there are a few important/critical items that must be correct. Clean & solid ground from the module ground tab to body or frame ground is crucial. Wiring should be 16 gauge stranded or heavier. Terminals should be soldered onto wires where possible; crimp-style connectors can fail & have on me before. Now I will only solder & shrink-wrap my connectors. That's about as complete as I can make this at the moment but let me know if you have any other questions or need other info. Thank you for the compliments, they are greatly appreciated.

@@The13thSword Thanks for that prompt reply. Have ordered the Ig Module and heat sink, will install with my new, but standard, plugs and cables and my OEM coil. Thanks again for all your work on this project!

@@ibbryn2190 No problem, just glad it helps people out. Your plan sounds good, let me know how it goes.

I will preface my answer by saying that I have never tried to do this conversion on a 22RE personally, so I have no real world practical experience on how that would turn out. I am not entirely sure if it would work, or work well enough to be a viable alternative. After doing a bit of research the main difference between the 22R & 22RE ignitions is that the carb system uses a vacuum advance/retard & the EFI system doesn't. The EFI distributor doesn't have the vacuum diaphragm system on it. This leads me to believe that the EFI ignition control module (ICM) also regulates the ignition advance in tandem with the ECM (engine control module). With that said, I'd likely lean to the answer being a qualified no, it probably won't work well enough to be a viable alternative. One alternative is to source a working used ICM. There are several currently on Ebay for the 84 to 88 22RE. Or give Jim's Used Toyota Truck Parts in Denver a call. yodajims.com/ I've dealt with them several times before on my '78 & they usually had what I needed. If you can find a used but working Toyota OEM ICM that would be your best alternative to get the truck going again.

For anyone else reading this, what follows are my personal opinions, based on my own research & experiences. My personal opinion is that *currently available* MSD equipment isn't necessary, will cost you a lot more money than OEM-type parts and is of less quality than OEM-type parts. You're basically paying higher prices for the "name" & the now old racing association & previous quality of the brand of these parts. I have looked at the MSD parts you mention and really can't see any difference between them (except for quality) & higher grade OEM-type parts from Standard Motor Parts, Wells (WVE) or NGK. For example the Blaster 2 coil usually sells for about $65 US retail & is made in China. A comparable NGK coil (NGK 49030) is made in Japan (*very* good quality BTW) & normally retails for about $53 US. That's 18% less $ for a much better quality coil. The Standard UC12 is either US made or made in Mexico (the Mexican coils are still just as good quality as the US made one) & are about $40 US retail. That's 38% less $ for better quality than the MSD Blaster 2. As for the module the same issues apply. More $ for China-made parts vs US or Japan made parts. From much personal experience, the China-made parts (regardless of what brand name is on them) just aren't anywhere near as good in quality or durability. Any goof quality coil that is intended as a standard replacement will work with the HEI module. The usual Primary resistance is usually 1.3 to 1.7 Ohms & you'll get all the spark power you need from one of those. If you really want to go with a lower Primary resistance coil, you can consider the newer-style "brick" epoxy filled coil for a 1981 to 1988 22R carbureted engine (not EFI). The Primary on those is 0.2 to 0.8 Ohms with a Secondary of 7K to 13K. The Standard UF12 would work very well. www.rockauto.com/en/parts/standard+motor+products,UF12,ignition+coil,7060 Only thing different is that you'll have to figure out a way to mount it, due to it being a "brick" shape & not a canister like the old-style coil.

It's not a matter of a stronger spark but a more reliably consistent spark over the older contact points setup that was used before electronic ignition systems were created. Either the Toyota Electronic Ignition "Igniter" or the HEI module will be more consistent that a points system as it is electronically switched instead of mechanically switched. Plus mechanical contact points can wear or get pitted from arcing over time & cause weak or missed spark. The initial reasons for this conversion is that the original Toyota Igniter module stopped functioning, and that replacement Toyota Ignitors for the 20R are either very hard to find (even working used ones), and even if you could find a new one they are expensive. Last new one I saw was 5 years ago & they wanted $600 for it. The 4 pin HEI module like the LX301 is $25-$30, is widely available, & functions the same basic way the original Toyota unit did. The module is basically a switch that turns the power on & off to the Ignition Coil. How "strong" the spark is, is dependent on how the ignition coil was designed & made and the condition of the rest of your system, such as spark plugs, rotor, cap, wires & even how well your engine is grounded. As long as all this is in good condition there shouldn't be any need for a "hotter" or "performance" ignition coil. Most stock ignition coils will put out on average 40,000 volts, which is plenty for a street-driven vehicle. NOTE/TIP: If you are considering doing this conversion, don't "cheap out" on the ignition coil. I know from experience that they aren't worth using & don't last. Get a good quality brand like SMP/Standard, NGK or WVE/Wells. NAPA/Echlin is the same as SMP/Standard just with the NAPA name on it & usually at a higher price. Hope this answers your question. If you have any other questions about this conversion just ask.

What is "best" is always a matter of opinion. Many would say the coil that can handle the straight 12 volts input (805, see below) would be better, usually with the reason given that it would provide a "hotter spark" & therefore better combustion. However you'd also have to change to a higher quality of spark plug to handle that extra spark power correctly. If not, the "stock" spark plugs may deteriorate sooner than expected & give you a run quality issue. You'd also be well advised to use a "premium" spark plug wire set with those upgraded plugs & coil. Ignition components must be matched to work well with each other. I use the stock copper/nickel Denso 3027 plugs with a 0.031" gap (stock spec) plus the Standard Motor Parts UC12 (803) coil with the RU4 resistor, & a "standard" wire set. The engine runs well this way for me. The trick is basically a daily driver, not a performance vehicle, so I don't really need the extra performance. It's currently getting 20+ MPG city on non-ethanol gas. You could use the Standard Motor Parts UC15 (805) coil which doesn't require the resistor (full 12 volt power input) but I'd upgrade to platinum plugs, either the Denso 4501's or the NGK 7082's with a 0.040" gap. You need the better quality plugs & larger gap to take any advantage of the "hotter spark" output from the "full voltage" coil. Plus the higher quality plugs will last longer than the "stock" plugs" under that "hotter spark" condition. Plus a premium wire set made by either Denso or NGK would be wise. So basically, you need the resistor with the "803" coil (SMP UC12) or you don't need the resistor with the "805" (UC15) coil. Because the "803" coil isn't designed to handle the full 12 volts constantly; it will become internally damaged & stop working properly in 1000 miles or so (or maybe less). The "805" coil is designed to handle the full 12 volts, so no resistor is required The choice is up to you. Any other questions just ask, but be as specific with your questions as you can, so I can give you as complete a response as possible.

All of this sounds reasonably normal to me. I will explain. There should *never* be 12 volts at the W & G terminals, as it is connected to the Pickup Coil in the distributor & not to the vehicle battery. The Pickup Coil is basically a pulse generator that generate AC voltage. When turning, it should be putting out on average 3 volts AC. You can try to measure it with a volt meter if you want to, but you have to be sure you have the meter set up to read AC volts. You also have to be sure that the air gap on the Pickup Coil is set within specs, with one of the reluctor ring vanes pointing directly at the center of the coil core. Spec is 0.008" to 0.016", or 0.2mm to 0.4mm. I set mine right in the middle at 0.12" or 0.3mm. "12 volts" to B & C terminals is correct. It should be the same or maybe 0.1 volt less than resting battery voltage. Typical battery voltage at rest (vehicle not running) should be at least 12.5 to 12.6 volts. When cranking, battery voltage drops. When cranking, battery voltage shouldn't drop below 9.6 to 9.7 volts. So around 9 volts when cranking is pretty normal, IF you have a good battery & good, clean, solid connections. If battery voltage drops below that when cranking, you either have a bad battery, a bad battery to chassis ground connection, a high resistance (old?) battery negative ground cable, a combination of these, or all three. Connection could be dirty, corroded or loose. That also applies to positive connections, at both the battery & the starter. One of the most critical things with this mod is making sure the module has a solid ground connection. It can be a body or frame ground connection, but if the battery negative connection to frame or body isn't good & solid, it can be an issue. You didn't say whether you got this mod to run or not., what the precise voltages are, or whether you are running a ballast resistor or not. Those plus other factors could affect function. Let me know.

@@The13thSword I know I have a bad battery but I have it jumped unless that doesn’t work. I noticed that I wasn’t getting a spark after I installed the HEI module. I installed it like you did in the video. I grounded it to the engine bay where other grounds are just no spark.

Does it the module run off a fuse or just the 12 when I turn the ignition?

@@MrNunez1 The module and ignition coil should be wired into the the ignition circuit. That power is controlled by the ignition switch. That circuit has it's own fuse in the fuse block.

@@MrNunez1 OK but have you checked ALL of the grounds like I described in my earlier reply? The ground side of the circuit is like a chain; there can be several "links" (connections) that could be bad that need to be cleaned up & tightened. You have to be thorough with this older vehicles, as they often have things like that going on. The bad battery being jumped could be a problem, especially if the plates inside are shorted (common issue when a battery "goes bad"). It's better to test the system with a good battery in place on it's own. Have you resistance tested the Pickup Coil in the distributor with an ohm meter? If it's the old distributor/pickup coil, it could be worn & have high resistance, which would prevent it from generating a pulse signal to the module. The factory spec on the Pickup Coil is 130-180 Ohms cold. Is the ignition coil new or old? If old it also needs to be resistance checked with an ohm meter. I can't give you the coil spec on that because you haven't told what year or model of vehicle you are working on there. If the pickup coil tests good, another reason for no spark is too bif of an air gap on that coil. Set it to the spec I previously mentioned in my earlier reply. It would be very helpful on my end if you gave a complete description of all the new parts you've used w/brands & part numbers, plus any other actions you've taken.

I do not recommend it. The 22RE distributor doesn't have the vacuum advance diaphragm like the 22R version does. On the 22RE all ignition timing advance is handled by the Engine Control Module (ECM) computer. On the 20R & 22R ignition timing advance is mechanically handled by the weights in the distributor and the vacuum advance diaphragm, operated by a vacuum signal from the carburetor. If you're doing this conversion on a 20R or 22R it's best to use a 20R or 22R distributor, as either one will give you the ignition vacuum advance you need. NOTE: If using a 22R distributor, those have a double vacuum diaphragm setup, one for advance & one to retard the timing. The advance diaphragm is the outer-most one & that's the one that should get the vacuum signal from the carb. The inner diaphragm isn't used. Any other questions just ask.