Gary Lewis Posted June 12, 2018 Share Posted June 12, 2018 Jose, from Mexico, is looking for the components to convert his late father's '81 F150 to DS-II, as described on his introduction thread, here: Hello People ! But that's getting very little participation, so I thought I'd start this thread in the hopes that others will see it and jump in to help. As you can see in the other thread, his '81 has a computer-controlled ignition. But, with so many things being disconnected I'm pretty sure the computer will have the advanced locked in limp-home mode. So, I suggested that he convert it to DS-II, and he asked me to come up with a list of things he needs. Here goes, but when I go wrong please correct me. And, it looks to me like there are two approaches - go back with the Ford DS-II system or a one-wire HEI: FORD DS-II SYSTEM: Engine Wiring Harness: The engine harness on the truck must be the DS-III harness, so he will need a DS-II harness. And I know of only two ways to do that: Salvage yard: If one of you has a Windsor DS-II harness or can get one from a salvage it would save quite a bit of money. Painless: The only other way that I know of is by buying a Painless Performance #30812 harness. That's available from Amazon, Summit, Jegs, or many other places for $160. DS-II Module: He will also need the blue-grommet module, and that could come from a number of places: I may have an extra and will look later Amazon has a Motorcraft for $40.60, and a Standard Motor Products for $26.91. But there are lots of sources for them. Ignition Coil: A stock Ford coil would work perfectly: Again, I may have one and will look later. Or, this Standard Motor Products one from Amazon would be fine. Distributor: This Spectra Premium from Amazon would fit the bill. HEI One-Wire Distributor: Guys, why not just use an HEI-style distributor and be done with it? No need for a new harness, nor ignition box, nor coil. It is so much cheaper as here's one from Amazon for $50, but there are lots of other options. And, I realize he would need a relay and some hefty wire to light it up, but that's inexpensive and fairly easily done. So, help me think through this, please. And remember that he has to get all of this shipped to Mexico. Link to comment Share on other sites More sharing options...
85lebaront2 Posted June 12, 2018 Share Posted June 12, 2018 Gary, his ignition system on the truck is a TFI-IV unit as was normally used on EFI engines complete with the E-core coil. It makes me wonder if it is indeed a 351 (1981 should have been a 351M, not W) or in fact a 302. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 12, 2018 Author Share Posted June 12, 2018 Gary, his ignition system on the truck is a TFI-IV unit as was normally used on EFI engines complete with the E-core coil. It makes me wonder if it is indeed a 351 (1981 should have been a 351M, not W) or in fact a 302. Bill - I agree that it doesn't add up as a US-made 1981 could have had a 302, but that would have had a DS-II ignition - as well as a Tecumseh A/C compressor. But, might a truck made in Mexico have had later-style systems/components? Perhaps we should figure some things out before we send Jose off to buy parts. But, do you agree that an HEI-style dizzy would be the easiest way to go? Jose - There should be a label on the driver's door jamb. It is called the certification label and should look like the one here: http://www.garysgaragemahal.com/certification-label.html. Can you take a picture of it and post it? And, we need to make sure it really is a 302 as the distributor for a 351W is longer if I remember correctly. So, two ways to tell. The intake manifold is 8 - 9" wide on a 302 and 10 - 11" wide on a 351W. Another way is the lower thermostat housing bolt is really hard to get to on a 302 as it is behind the timing cover, but because of the taller block on a 351W the bolt is above the timing cover. Link to comment Share on other sites More sharing options...
85lebaront2 Posted June 12, 2018 Share Posted June 12, 2018 Bill - I agree that it doesn't add up as a US-made 1981 could have had a 302, but that would have had a DS-II ignition - as well as a Tecumseh A/C compressor. But, might a truck made in Mexico have had later-style systems/components? Perhaps we should figure some things out before we send Jose off to buy parts. But, do you agree that an HEI-style dizzy would be the easiest way to go? Jose - There should be a label on the driver's door jamb. It is called the certification label and should look like the one here: http://www.garysgaragemahal.com/certification-label.html. Can you take a picture of it and post it? And, we need to make sure it really is a 302 as the distributor for a 351W is longer if I remember correctly. So, two ways to tell. The intake manifold is 8 - 9" wide on a 302 and 10 - 11" wide on a 351W. Another way is the lower thermostat housing bolt is really hard to get to on a 302 as it is behind the timing cover, but because of the taller block on a 351W the bolt is above the timing cover. The 351W will also have 2 ribs from the block behind the timing cover going up toward the intake manifold front area. Yes, the damn French ignition system is the easiest solution but I recommend using a relay to feed it because of the current draw, it also makes sure the resistance wire is bypassed. Link to comment Share on other sites More sharing options...
Jose Posted June 12, 2018 Share Posted June 12, 2018 Gary, his ignition system on the truck is a TFI-IV unit as was normally used on EFI engines complete with the E-core coil. It makes me wonder if it is indeed a 351 (1981 should have been a 351M, not W) or in fact a 302. Hi 85lebaront2, There should be no doubt, it is a 302 (not 302 H.O. nor 351), and i can tell it by the firing order 1-5-4-2-6-3-7-8 I took a shot of the certification label at the driver's door, unfortunately it wont be of much help as it is almost gone by corrosion, besides it was printed in spanish. I appreciate all your comments ! Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 12, 2018 Author Share Posted June 12, 2018 Hi 85lebaront2, There should be no doubt, it is a 302 (not 302 H.O. nor 351), and i can tell it by the firing order 1-5-4-2-6-3-7-8 I took a shot of the certification label at the driver's door, unfortunately it wont be of much help as it is almost gone by corrosion, besides it was printed in spanish. I appreciate all your comments ! Well, it certainly isn't a Made In The US truck. Jose - I'm reasonably sure that the easiest and cheapest way to fix your ignition system is to go with the HEI-style distributor. But you will have to add a relay and fuse. Use the Red/Light Green wire that probably goes to the coil at present to pull the relay in. And use a minimum of a #12 wire to the battery through a fuse to provide power to the relay. Link to comment Share on other sites More sharing options...
Jose Posted June 13, 2018 Share Posted June 13, 2018 Well, it certainly isn't a Made In The US truck. Jose - I'm reasonably sure that the easiest and cheapest way to fix your ignition system is to go with the HEI-style distributor. But you will have to add a relay and fuse. Use the Red/Light Green wire that probably goes to the coil at present to pull the relay in. And use a minimum of a #12 wire to the battery through a fuse to provide power to the relay. Hi Gary, I agree, this option is by far the more convenient from all point of view, I will procurate it from Amazón as it seems to be the fastest and reliable way. Keen to show you guys the outcomes of this change ! Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 13, 2018 Author Share Posted June 13, 2018 Hi Gary, I agree, this option is by far the more convenient from all point of view, I will procurate it from Amazón as it seems to be the fastest and reliable way. Keen to show you guys the outcomes of this change ! Good luck! But, do you need a wiring diagram for the relay? Do you need tips for pulling & replacing the distributor? Link to comment Share on other sites More sharing options...
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