I have a 92 GMC typhoon had these models fail so often that I probably have bought ten or better. I was looking for a more permanent fix. I am going with a complete rewire and eliminating the og distributor for a holley duel sink where it will give cam/crank sensor. Also eliminating the batch fire injection system to a SFI system like the grandnational.

@@jdgreen214a lot of the modules fail because of poor grounding. The wires in the primitive computer chip don’t take much overload before they pop. Even more so on brand new china modules. Once the circuit trace burns it’s dead. Fix the external problem first before you continue

@@Gleone58 I think the wiring had run its course as well. It's interesting because we are now entering the age where the classics went electronic. I have a 87 grandnational as well and had to put some money in electrical updates as well performance improvements. What made the previous muscle cars so collectible is their absence of electronics minus the lights and stereo systems. Can you imagine 30 years down the road the hellcats and newer muscle cars that 100% rely on electronics needing fixes to keep going? I'm sure part of the ICM failure was do to cheep parts also the I'm not 100% sure what it's called is it a thermal pace? It sits on the bottom of the ICM not sure if enough was placed. I heard the dual sync distributor gives a better signal than any of the OEM or OEM style distributors.

Never thought to try that, thanks for sharing.

same, just with an 84 G20 van

The 7 pin modules are for TBI systems that don’t utilize a crank position sensor. On these, you have a two pin connector (+/C) for your module and coil. A two pin connector (N/P) for your pick up/hall sensor A four pin connector (A/B/C/D). Pin A is your Distributor Ref High input to the PCM. Pin C is your Distributor Ref Low to the PCM. These two are essentially your RPM signal the PCM uses for injector timing. Pin D is the good old fashioned spark timing control (ignition timing). Pin B is your ignition module bypass as explained in this video. Those systems have no other rpm signal except for the signal produced by the pick up coil. This is in essence what we know as a cam position signal today. The PCM uses this signal to control the TBI injectors, as it needs to know what the engine is doing and fire the injectors accordingly.

You're describing the 8-pin module.

@blownzed I just added some part numbers in the description... Thank you!

Unfortunately the TBI ESC modules do not work stand alone. They do not control timing. They are connected to the TBI ecm, and the ECM controls timing. The older steel box ESC modules can still be found if you punch in the part numbers on a search.... 16029011 or 16042121

@@raysoto1969 thank you for the response and the information Ray. I to have been using the four pin HEI module for every dis with mechanical advance from waste spark four cylinder engines to old Toyota six cylinder engines to ford and Chrysler V8s my next one will be too try a 4.3 vortec engine with a m 90 supper charger on propane. Again thanks for the info and keep up the good work your video's help me.

@@domenicscarfo1866 Awesome... you should make a video about your builds 👍

Yes, Echlin is one of the few current brands that offer decent quality these days. I prefer to buy new old stock, NOS, on ebay. Or anything not made in China, which is becoming rare

Yes, I've seen people with four and seven pin modules connected to points also. You can find diagrams on the internet on these also

Yes it will

thanks@@raysoto1969

The P pin on the 7 pin module is a very weak AC signal. It can not be tested with a test light. The B pin should get only 5 volts when the vehicle is running. But zero volts when the vehicle is not running. The R pin is the signal the ECM needs to pulse the injectors. It is a very weak square wave pulsing grounding signal from the 7 pin module. The only way to test it is with an oscilloscope. Therefore, it's easier to just change the 7 pin module for another one and see if it fixes the problem.

@@raysoto1969 Sorry I was not clear. Too much info I talked about. 1. The pickup coil AC low voltage, have you any idea of the real normal voltage range ? Everything I have found so far is all over, from 0.3VAC to 3 VAC. 2. The shop manual says to check the pickupcoil by disconnecting it and putting a test clip on battery positive and just touch the P terminal on and off ..and you should get spark. ( assuming no spark prior that was pickup coil suspect) . 3. For the R terminal that feeds the purple/wht for injector pulse I know it is reading 1.3 to 1.8 V with multimeter. Of course it is in a square wave and if 50% duty cycle , peak could be 2.6 to 3.6V. Just wondering if you ever checked the voltage for yourself ? 4. Again, back to the shop manual. It says disconnect the 4 wire connector ( R, E, B , and also a Ground ) . Test light clip to battery positive, touch pointer to harness side R purple/ wht that goes to ECM for just an instant , on and off , and the fuel pump should prime and the injector noid light should flash. ( I have only the fuel pump priming). So I thought maybe my 1.3 to 1.8 was not enough voltage and wondered if you ever checked a good running one , so I can compare ? I think I have an ECM problem, ( probably injector driver problem) , but I just wanted to be sure. Last night I put in a new module, but problem is still the same. THANKS !!

@danieljurgill1681 Yes, I get about the same voltage readings as you. You are checking it correctly, and it sounds like the module is not the problem. Will more likely be problems in the harness or the ECM itself

​@@raysoto1969 Good news. Installed a remanufactured ECM...car started right up !

@@danieljurgill1681 Awesome!

You can use a wide variety of coils with the HEI distributor. They can even be externally located with minor modifications to the cap

@@thisisyourcaptainspeaking2259 Not the factory 7 pin on HEI's. Some aftermarket & marine modules have timing built in

@@raysoto1969 I guess that would be the 8-pin module that has a built in limp-mode advance curve. There have been so many, I lose track, lol.

Sorry, I should have explained better. Do not use the condenser The B terminal is power, connect it to 12 volts. The C terminal goes to your coil negative. Connect the small G pin directly to your points. Then make sure you have a 1K ohm resistor connected from 12 volts to the G pin also.

@@raysoto1969 thanks for responding back. I'll give it a go and let you know the results or if I have any more questions. Thanks again.

Ok first hurdle, difficult finding 3 prong hei modules and expensive for nos, so if one can convert a 3 prong into a 4 prong, can you convert a 4 prong into a 3 prong????? How would I wire a 4 prong into a 3 prong, if thats possible?

Do you have a source for your 1 ohm resistor?

@FIXANDREPAIR The 3 prong module can still be found on ebay for about $13 free shipping. Punch in one of these part numbers... D1919 or LX314. A pack of 1K ohm resistors can also be found on ebay for about $3 free shipping. If you prefer to use the 4 prong module, you can wire it exactly the same as I mentioned, but you would need to wire the W pin to ground.

The eight pin module was not used in the large cap HEI distributor. Although it is an interesting module

Then for some reason your ecm is not sending a timing signal to the module. Could be bad ecm or wiring. It runs when when the 4 wire connector is disconnected... then the pickup coil is good and probably the module is good. It's going to be something bad outside of the distributor

@mattsurode85 You can use the 4 pin module for points the same way... just ground the W pin

@@raysoto1969 tyvm ive been trying to use an hei 7 with 5v supplied to it constant but they keep having issues

@mattsurode85 yea, that's a more complicated circuit. I prefer the 3 or 4 pin module

@@raysoto1969 is this supposed to work with a hall signal? Trying to get this to work with an after market ecu

@mattsurode85 No, none of these modules are used with hall effect. However, some later HEI distributors had a hall effect sensor (separate from the module) that was used in engines that had sequential fuel injection