85lebaront2 Posted May 29, 2020 Share Posted May 29, 2020 Ok, a few items from dealing with my son's 1986 F150 EFI 302. First, the 1985/86 EFI system uses the TPS voltage as the idle set point, not rpm. The set point is pretty sensitive as it is 1.0 VDC +/- .05 VDC. This is critical as the EGR controls start at 1.10 VDC and too much throttle opening will cause a solenoid "chatter" or a surging idle as the EGR opens than closes. The 1987 up systems use a "duty cycle" solenoid rather than the Vacuum/Vent system in 85-86. The wiring harnesses on these were also horrible quality, frayed insulation to the point of shorts and grounds. I was able to retrieve the harness(s) I had obtained for him and have perfect set of solenoids for the system. I will not be able really lay these out and do a full inspection/photos until probably 1 June as I am not at home nor will be till Sunday afternoon at the earliest. Ok, did a quick scan of the stuff in the box, it appears there are 2 sets in there. Some damage on each, mostly some missing plug shells. Link to comment Share on other sites More sharing options...
railwayboiii Posted June 7, 2020 Author Share Posted June 7, 2020 Ok, did a quick scan of the stuff in the box, it appears there are 2 sets in there. Some damage on each, mostly some missing plug shells. Fun day today. Got codes (fun!) 23- TPS out of range 10- Cylinder balance (funny story, I was dumb and unplugged the live spark wire from the distributor to see if it was truly dead or not, talk about a shock!) 63- TPS circuit fault 31- EGR valve control fault/EVAP fault 18 Loss of tachometer input, IDM circuit faulure, SPOUT circuit grounded (what the heck is IDM/SPOUT?) Going to test the TPS and EGR to see if it's in range, but I've been digging up other stories of 86's having the same rough idle and richness issues with the codes. I thought that the richness issues could be timing, but fiddling with it did little to no good, especially since my timing mark is too far off! I'm pretty sure the balancer has slipped, so it's all by feel now, until I can get it replaced. I had replaced my TPS sensor the the beginning of the Unscrewing last year. Could a bad ground toast it? Thank you for your help! Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted June 7, 2020 Share Posted June 7, 2020 Fun day today. Got codes (fun!) 23- TPS out of range 10- Cylinder balance (funny story, I was dumb and unplugged the live spark wire from the distributor to see if it was truly dead or not, talk about a shock!) 63- TPS circuit fault 31- EGR valve control fault/EVAP fault 18 Loss of tachometer input, IDM circuit faulure, SPOUT circuit grounded (what the heck is IDM/SPOUT?) Going to test the TPS and EGR to see if it's in range, but I've been digging up other stories of 86's having the same rough idle and richness issues with the codes. I thought that the richness issues could be timing, but fiddling with it did little to no good, especially since my timing mark is too far off! I'm pretty sure the balancer has slipped, so it's all by feel now, until I can get it replaced. I had replaced my TPS sensor the the beginning of the Unscrewing last year. Could a bad ground toast it? Thank you for your help! One thing about codes. Always start with the lowest number first. Often fixing one thing will clear others higher up. SPOUT is "SPark OUT" it is the computers way of controlling advance. When setting base timing you always need to remove a jumper (or in very early systems, disconnect the wire) Your '86 should have a little plug close to the distributor. The most important ground is the one coming from the main harness directly to the battery - terminal. Link to comment Share on other sites More sharing options...
railwayboiii Posted July 3, 2020 Author Share Posted July 3, 2020 One thing about codes. Always start with the lowest number first. Often fixing one thing will clear others higher up. SPOUT is "SPark OUT" it is the computers way of controlling advance. When setting base timing you always need to remove a jumper (or in very early systems, disconnect the wire) Your '86 should have a little plug close to the distributor. The most important ground is the one coming from the main harness directly to the battery - terminal. Today leaps and bounds have been made. I wasn't able to get my hands on a Motocraft TPS but a Standard one (for 44 dollars I hope it's near the same!) Installed the new TPS, engine can hold a idle, but still a light surge issue. Did some testing, engine would nearly die and sputter after coming down from pressing on the pedal. After this, me and my neighbor readded the Cat and what a difference did it make! The engine would not die after coming down from high revs except if we floored it! I'm happy but I'm shocked that the exhaust system being whole had such an effect on it! In hindsight now, I wonder if the EGR valve is faulty/dirty. Tomorrow, I will do a full cleaning of it. Â Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 3, 2020 Share Posted July 3, 2020 Today leaps and bounds have been made. I wasn't able to get my hands on a Motocraft TPS but a Standard one (for 44 dollars I hope it's near the same!) Installed the new TPS, engine can hold a idle, but still a light surge issue. Did some testing, engine would nearly die and sputter after coming down from pressing on the pedal. After this, me and my neighbor readded the Cat and what a difference did it make! The engine would not die after coming down from high revs except if we floored it! I'm happy but I'm shocked that the exhaust system being whole had such an effect on it! In hindsight now, I wonder if the EGR valve is faulty/dirty. Tomorrow, I will do a full cleaning of it. That's good news! Congrat's! I didn't realize it would make that much difference, but that's good to know. Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 4, 2020 Share Posted July 4, 2020 That's good news! Congrat's! I didn't realize it would make that much difference, but that's good to know. Gary, the 1985/86 EFI is a bit different in the way the TPS effects the system. On these the closed throttle voltage is what determines the idle stop setting, starting in 1987 it is a IAC closed rpm and the EEC uses the voltage measured at startup as closed throttle (why it is not good to open the throttle when starting). If the voltage is a bit too high, the EEC will open the EGR vacuum valve and then try to balance things resulting in a surging idle and chattering solenoid valves. There is a thread Matt posted on FTE on this issue, his was caused by an aftermarket TPS that would not come low enough on the voltage to make the EEC happy. Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 4, 2020 Share Posted July 4, 2020 Gary, the 1985/86 EFI is a bit different in the way the TPS effects the system. On these the closed throttle voltage is what determines the idle stop setting, starting in 1987 it is a IAC closed rpm and the EEC uses the voltage measured at startup as closed throttle (why it is not good to open the throttle when starting). If the voltage is a bit too high, the EEC will open the EGR vacuum valve and then try to balance things resulting in a surging idle and chattering solenoid valves. There is a thread Matt posted on FTE on this issue, his was caused by an aftermarket TPS that would not come low enough on the voltage to make the EEC happy. They sure tried some strange stuff before settling on "the right way". Link to comment Share on other sites More sharing options...
railwayboiii Posted July 4, 2020 Author Share Posted July 4, 2020 They sure tried some strange stuff before settling on "the right way". It seems as if good deeds do not go unpunished. After doing a full caliper, pad, bearing and rotor installation, it was finally time to bleed the system and take it for the first test drive in months. Unfortunately, after 3 hours of trying to open the back brake bleeder, we find out that it is VERY rusted. I had the bright idea to try to approach it from the tire side, we took out the tire and drum and found that ALL the springs have rusted off!!!! The cherry on top, is while working on freeing the screw, the brake line started leaking due to rust!! It's VERY overdue for a brake rebuild. So now, new hardware and shoes are being ordered and I'm going to sand down the rust off the drums and repaint. It seems as if my new project this week will be getting a healthy coat of POR-15 in the back (she's flaky) In addition to this, what diameter of brake line should I get? Any tips? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 4, 2020 Share Posted July 4, 2020 It seems as if good deeds do not go unpunished. After doing a full caliper, pad, bearing and rotor installation, it was finally time to bleed the system and take it for the first test drive in months. Unfortunately, after 3 hours of trying to open the back brake bleeder, we find out that it is VERY rusted. I had the bright idea to try to approach it from the tire side, we took out the tire and drum and found that ALL the springs have rusted off!!!! The cherry on top, is while working on freeing the screw, the brake line started leaking due to rust!! It's VERY overdue for a brake rebuild. So now, new hardware and shoes are being ordered and I'm going to sand down the rust off the drums and repaint. It seems as if my new project this week will be getting a healthy coat of POR-15 in the back (she's flaky) In addition to this, what diameter of brake line should I get? Any tips? 3/16 Replace the hose/splitter/axle vent bolt while you're at it. Note that the left side brake tube uses a 7/8-20 fitting at the splitter. If you're not making your own lines be SURE to get the adapter bushing to fit the brass block on the hose. The above is a public service announcement, from the sponsor of this program.... Link to comment Share on other sites More sharing options...
railwayboiii Posted July 4, 2020 Author Share Posted July 4, 2020 3/16 Replace the hose/splitter/axle vent bolt while you're at it. Note that the left side brake tube uses a 7/8-20 fitting at the splitter. If you're not making your own lines be SURE to get the adapter bushing to fit the brass block on the hose. The above is a public service announcement, from the sponsor of this program.... Thank you!!! Link to comment Share on other sites More sharing options...
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