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  1. #1

    Default Installing an EGR system

    I am considering putting an EGR system on my car to improve the gas mileage. It has a stock '84 HO 302 with a factory four-barrel intake and EGR plate that is currently blocked off (no EGR valve or plumbing). From what I gather, the EGR system is only good for 1 - 2 mpg increase but this car is my daily driver so any little bit will help. At that rate, the EGR valve will pay for itself in six months.

    I've always been the hot rodder type to ditch the "emissions junk" so I don't have any experience with EGR systems. The more I read about how EGR works and what it does, it actually makes a lot of sense to use it on a street car. Other than the EGR valve, what else will I need to acquire to get it all hooked up? How well does the EGR work on a carbureted engine? Is it even worth the effort?

  2. #2

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    Well, I'm not sure about the carb'd models, but you would probably need the EGR valve, the tube from the exhaust to the valve, the EGR position sensor, and that should do it


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  3. #3

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    IMHO, exhaust gases recirculated, to reduce oxides of nitrogen at part-throttle (off-idle carburetor ported vacuum signal opens EGR), by theoretically cooling combustion temperatures with theoretically inert gases, theoretically allowing increased ignition advance (this is the only slim chance of any possible increased miles per gallon, but with an electronic ignition distributor with mechanical and vacuum advance, unless you physically make increased ignition advance happen throughout the rpm range with tuning of mechanical/vacuum advance, it doesn't happen by itself), for theoretical increases in fuel efficiency. Also IMHO, EGR is an add-on band-aid-to-meet-emissions-"standards" complication and replication of the normal engine function of camshaft overlap, and theoretically inert gases added to the intake charge cannot take the place of a complete lean fuel mixture charge in combination with maximally increased ignition advance, that actually improves fuel efficiency.
    Last edited by Walking-Tall; 10-18-2016 at 07:44 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  4. #4

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    It's really hard to find information about how to "hot rod" an EGR system. The vast majority of what's out there is people removing it. The guys that keep it recommend keeping it 100% original factory stock, any deviation is almost certain doom. The only article I've found, so far, where a guy tweaked the EGR is here;

    http://www.autospeed.com/cms/article...art-2&A=112730

    He had the advantage of an electronic EGR so he could adjust it on-the-fly. Increasing the EGR flow above the factory setting netted a 3% increase in gas mileage and that is on a car that already gets remarkable gas mileage. When he reduced EGR flow the gas mileage dropped 12% from the stock baseline.

    I'm anxious to start experimenting with this. I bought a Motorcraft CX-1223 EGR valve that comes with a bunch of calibration washers. No on-the-fly adjustment but it should allow enough adjustment for experiment sake.

    I also plan to modify my carb so it has both the factory 4180 EGR port and a 4160-style vacuum port to see what [if any] difference there is between the two in regards to EGR function.

  5. #5

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    I had a thought on how to build an electronically adjustable EGR valve. The stock EGR valve has a positive back pressure transducer built into it. The transducer controls the EGR valve by opening and closing a vacuum bleed valve in the diaphragm. The transducer reads the pressure in the EGR valve between the pintle and exhaust restrictor. When the pintle is closed, the transducer sees only the exhaust pressure. When the exhaust pressure rises, the transducer closes the bleed valve and the pintle opens. If manifold vacuum is high and exhaust pressure is low then the pressure behind the exhaust restrictor will drop drastically, the transducer will open the bleed valve and the pintle will close again. As engine load increases, the manifold vacuum drops and exhaust pressure rises so the pintle will open farther and admit more exhaust into the intake. Because the pressure is being monitored after the exhaust restrictor, it its the size of the orifice in the restrictor that determines EGR flow. A smaller restrictor will have a greater pressure drop so it takes less EGR flow to trigger the tranducer to close the pintle. A larger restrictor has less pressure drop so it takes more EGR flow to trigger the transducer. The only way to tune this system is to remove the EGR valve and swap out restrictors.

    Earlier this week I was helping my nephew with his Jeep. It idled perfectly but would sputter and die when he gave it a little gas. We figured out that his EGR back pressure transducer was stuck and not bleeding the vacuum to the diaphragm. The cool thing was that his EGR had an external transducer so we were able to pop it open, clean it out, and then it worked perfectly. The transducer was insanely simple, basically nothing more than a T-fitting with a rubber diaphragm at the bottom of the T. There was a very light spring between the T and the diaphragm. The bottom of the diaphragm was plumbed to the EGR valve, between the exhaust restrictor and pintle. With a small pressure on this line, the rubber diaphragm would move up and block the open port on the bottom of the T-fitting. I started thinking that a system like this would be easier to tinker with since the EGR flow could be adjusted by changing springs in the external transducer.

    It occurred to me that the mechanical transducer could be eliminated entirely. Hook a 2-bar MAP sensor to the pintle well, feed that to a comparator that triggers a vacuum solenoid that actuated the EGR valve. The other leg of the comparator goes to a trim pot so the threshold could be adjusted on-the-fly. I'm a bit of an electronics geek so I have everything in the junk box to build this. The only thing I don't have is an EGR valve without a built-in back pressure transducer. Did any Ford vehicles ever use an External back pressure transducer? Do any other makes have EGR valves that will bolt up to a Ford EGR plate?

  6. #6
    FEP Super Member xctasy's Avatar
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    The real revolution isn't EFI, but control systems.


    EGR cools intake charge. If done right, it also can improves part thottle mpg. Its generally a win-win situation.

    Like secondary AIR, the stock EGR system in an 84 is out of the ark. No, wait, out of the neanderthals cave.

    You can improve and optimise it. You can't say its stock, but you can say Its present.

    So optimise it and enjoy it!

    Secondary AIR is easy to control via modern electric air pumps.

    And esepcially, cold start warming without a choke, the curse of non EFI cold start warm ups and the creator of cold start cylinder wall washdown and engine wear.


    So you can make a stock carb 5.0 very economical.

    The EGR change is an easy one since it doesn't draw the amps remote cooling fans, or an electric AIR pump does, so its a very benefical change.

    My favorite though has to be supra stoichometric air fuel ratio changes by the a servo controll adjusta jet or the air craft kit.


    Like this


    from

    tomcn@earthlink.net for US $150 dollars excluding post and packaging.
    -Tom McNeilly
    14001 East Williams Field Rd.
    Gilbert, AZ 85296
    International phone number is +1-602-899-7613

    He's in Arizona, USA.

    Northwest Aero Products also has them available. They are at
    13812 179th Avenue SE
    Monroe, WA 98272
    International phone number +1-360-805-8183
    Call displayed telephone number to ask for respective email address of Northwest Aero Products.

    Follow those recomendations and you'll be able to adjust total jetting.Its got a PV block off, but there are other ways to control air fuel spikes requirements.

    There was also an electonic power valve by Holley for 2 and 4bbls frsome years back, but it was withdrawn.

    The plate above is a throttle leaning device used for carb light aircraft.

    This allows someone to remove the choke blade, or do a Dominator style air horn removal. The system is a throttle lean aout device that on terestrial autombiles, allows rich starting, and then lean off during warm up. Servo control could run through a feedback loop.

  7. #7

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    Ford did use external back pressure transducers. They mounted on a spacer that fit between the EGR valve and carb spacer. If I can dig up one of those spacers then that would save me the work of building one. I also need to find an EGR valve from one of these systems.

    Digging through my junk box, I found a PFE sensor. Ford used these on some cars for exactly what I want to do, monitor EGR pintle well pressure. It works similar to a 2-bar MAP sensor in that it outputs about half reference voltage at atmospheric pressure. The advantage of the PFE sensor [in this application] is that it's range is only two or three PSI above and below atmospheric so it will provide much better resolution than a 2-bar MAP sensor.

    I found a few vacuum solenoids in the junk box but I'm not sure if they can handle the necessary constant fast switching. May need to take a trip to the junk yard to get an actual EVR.

  8. #8

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    When researching single-diaphragm EGR valves, I discovered that Ford has already made one that has a tube to hook up a PFE sensor. They were used on '83-85 Escorts. The tube comes out the bottom so it may not clear the intake runner on a V8. I found a NOS one really cheap so I can see if it fits [when it gets here].

    I've kind of shifted gears on the EGR control system. Instead of building an analog controller, I'm adding code to my digital ignition controller so I can adjust the EGR and advance on-the-fly with a single hand-held programmer.

    Does any one know [or can check] the frequency of the PWM signal to the EGR valve regulator in an EEC-IV system? I've been though the EEC Bible several times, it talks about duty cycle but give no mention of the frequency.

  9. #9

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    Tomco to the rescue! After countless hours of searching, I finally found this; http://www.tomco-inc.com/Tech_Tips/ttt32.pdf At the very end it shows a scope trace of the EVR cycling at 200Hz.

  10. #10
    FEP Super Member xctasy's Avatar
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    Quote Originally Posted by mrriggs View Post
    Tomco to the rescue! After countless hours of searching, I finally found this; http://www.tomco-inc.com/Tech_Tips/ttt32.pdf At the very end it shows a scope trace of the EVR cycling at 200Hz.
    What is the replacement Tomco single-diaphragm EGR valve?


    Ha hah!

    Right back atcha! This is one of my favorites, because there are sub fault code component failures all the time with in service EGR and OBD 1 systems.

    I found 19 even better!

    http://www.tomco-inc.com/Tech_Tips/ttt19.pdf

    About a week later, when he encountered the problem, he plugged the vacuum line to the EGR valve and that seemed to take away his problem. He brought the vehicle back to us, but there still were no codes recorded. We removed the EGR valve to check for carbon deposits. There was no carbon buildup that could be causing a problem. Next we checked the EGR valve position sensor’s (EVP) resistance specs according to the Ford service manual. The EVP
    sensor fell within specifications. Every once in a while when we ran the resistance test on the EVP sensor, the analog meter would have a slight hesitation in needle movement. We removed the EVP sensor and carefully cut it apart. Once apart we noticed a section of the resistive material on the ceramichad worn through. This worn section caused the fluctuation in the analog meter. It also tricked the computer into thinking that the EGR valve wasnot open enough. The computer would compensate by opening the EGR valve even more. Too much EGR valve will cause a hesitation, or astalling condition. We replaced it with a TOMCO EVP sensor and he has incurred no further problems.Intermittent problems can be hard to findespecially when there are no codes and the sensor involved has an intermittent fault. Thanks to an alert technician and his screeningof the symptoms we were able to help him solve this elusive problem
    This is the intermediate step Ford made in 1984 when the carb version of the EECIV 4.9, 2.3 Tempo and 2.3 OHC Lima came out with TFI. All had a feedback 1-bbl carb, either Holley 1949 or 6149-6153, or the similar looking but very different inside feedback Carter YFA. Hated by many because of the its goes off line when the knock sensor signal goes haywire, and you end up with a 10 degree total advance enigine...

    By the time the CFi version of the 1-bbl Tempo came out, fully electronic EGR. I think the 5.0 CFi and 3.8 CFi used the next step to TAB/TAD

    We have looked at the EGR solenoids and the EGR valve and EVP for testing and problems. But there could be a low vacuum problem. Check the source vacuum and make sure there are no leaks in the line to the solenoid. Also make sure you check the line to the EGR valve itself. In many cases the systems we have been looking at start to open the EGR valve at 1 to 1.5 in HG and only need a maximum of 4 in HG to open fully. When checking to see if opening an EGR valve will make a difference in RPM, we hook up a vacuum pump and apply 15 inches of vacuum. This is almost 4 times as much vacuum as the EGR valve will see under normal operating conditions. This might cause us to miss a partially clogged or sticking EGR valve. Apply the vacuum to the valve that it will see under normal operation to test it more accurately
    A resistance check can be performed on the EGR solenoid(s). A rule of thumb for resistance on these solenoids is:

    EGRC/EGRV Solenoids should be 32 to 64 ohms.

    EGR Shutoff Solenoids should be 51 to 108 ohms.

    EVR Solenoids should be 20 to 70 ohms (100 to 135 ohms for 7.5L engines).

    Fig 6 shows the general operation to the Fords std EEC IV black and grey wire



    Lasly, you golden gem

    Figure 8 shows the signal of the EVR cycling on and off. As you can see we have set the scope voltage at 5 volts per division and the time base at a 5 ms per division. This pattern was captured loading the engine in drive. The Scanner reads about a 40% duty cycle. The maximum high of this signal is 13 volts while the low voltage is 8.8 volts. If you look at the on time of the signal (where it drops to a low voltage) it appears to be at the 40% duty cycle we have seen on the Scanner.



    Thanks.

  11. #11

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    The Escort EGR valve does fit on a V8. The PFE tube was right against the rear intake runner so I bent it bit to be sure it wouldn't interfere with the fitment of the valve. The main body and pintle size look the same as a V8 EGR valve. However, the calibration washers that came with it all have tiny holes which isn't surprising since it was meant for a four-banger. I'll make a new washer with a 1/2" hole. I imagine that should be close enough since I will be able to fine tune it electronically.

    If anyone was wondering, the output impedance of a PFE sensor is 3k Ohm. Unfortunately, that is too high to hook directly to the ADC on the microcontroller so I'll have to build a buffer. Out of curiosity I also measured the output impedance of a GM 2-bar MAP sensor - 2.2k Ohm. I have some other oddball 2-bar MAP sensors that have 50 Ohm output impedance but the higher resolution of the PFE sensor is worth the extra effort to hook up.

    Still a lot of work to do to the controller. What started as "add a few lines of code" has turned into re-writing the entire program from the ground up. The original program was written for drag racing so it had no input for MAP or ECT sensors. I'm also adding a purge solenoid output, "Economizer" light, and replicating the factory up-shift light which will automatically switch over to a conventional shift light when the pedal is to the metal.

  12. #12

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    I'm starting to realize that it will be much easier to hook all this up if I start with a CFI wiring harness. The sad part is that this was originally a CFI car but the harness was hacked up when it was converted to carb. When I say hacked, I mean HACKED! Scotch Locks, wire nuts, even wires twisted together and left bare. It is a mess.

    The car is an LTD LX, would a CFI harness from a 5.0 Mustang or T-bird be the same as what was in it originally?

  13. #13

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    This forum is an amazing resource! I now have an actual LTD LX CFI harness (thanks Fastlane).

    Since it is already configured to use an EGR valve position sensor [EVP], I'm curious what it would take to make it run off of that? I imagine it wouldn't be as self-regulating as the PFE setup and would require lookup tables. That wouldn't be a problem if I had some idea what the stock computer was looking at to determine the target EVP. I've been able to find examples of lookup tables for spark and fuel but nothing for EGR.

    I also picked up a Tripminder in hopes that it would allow me to see instant changes in gas mileage while I adjust ignition timing and EGR flow at cruising speed. At this point, the plan is to get the Tripminder working then configure the ECU for simple manual control of the EGR. If EGR doesn't show any improvement in mileage then there is no reason to waste time programming the ECU to control it.

  14. #14
    FEP Super Member xctasy's Avatar
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    Good fortune. It'll suprise you how well the brain dead pre OBDII's respond.


    Net injector duty time and fuel consumption is a much better assessment parameter for a set road load than EGT or O2 sensor output.


    We lost a lot of good information when the Trip Minder got minised and nested as a data option in cars. The age of gluttony was the 1985 to 2008 era, and I'm not even sure we are back on track since safety over rides fuel consumption for many. The advent of the electronic throttle has forced the throttle applications to go into the soft mode, as we race to keep up with significantly faster average traffic speeds.

    I'm not knocking the 23 years from 85 to OCT Owe Eight, it was nice to see the trancending rise of hp, but actual power to weight didn't improve much. The reverse trenches were also hefty weight gains in the 1999 and 2006 S cars.




    I like the concept of EGR, because you can prove MPG imporovment, its not just hot air, its, if you pardon the expression, a benfical cold fart!

  15. #15

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    There have been a lot of other things on this car that have required my attention. I'm still plugging away at this, slowly but surely.

    I had to pull the Tripminder apart to swap the mounting brackets (it came from a Crown Vic). While it was apart, I replaced all the electrolytic capacitors and cleaned the switch contacts. Installation was as simple as removing the clock from the dash and putting the Tripminder in it's place. The power connector for the clock plugs right into the pigtail on the Tripminder. There is a separate connector on the Tripminder pigtail for the fuel and VSS inputs. I still need to hook those up. This car already has a VSS for the cruise control so that part is easy. Since my car is carbureted, I have to use a fuel flow sensor. I got the sensor mounted and plumbed last weekend so it just needs the wires hooked up.

    I finished writing the code for the controller and gutted a junk EEC-IV box to build it in. I've got at least a month to build the ECU. That's how long it will be until I can swap in the CFI harness. This is my only car right now so I can't tear all the wiring out of it until summer time when I don't need it to drive the kids to daycare.

  16. #16

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    A couple weeks ago I realized that summer is in full swing and I hadn't finished building the controller. It was hard to get motivated to go out in the garage after getting the kids to bed so I set up the electronics lab on a folding table in my bedroom. Now when I decide to turn in I see it sitting there and think, "I'll just work on it for a little bit," then spend half the night slinging solder.

    It's been a slow process since I'm designing it, drawing up a schematic, and building it all at the same time. The circuit board is mounted in an EEC-IV box and is about 98% done. I'll do some bench testing on it then wire-wrap it to the 60-pin connector.

    This is the schematic; http://www.gofastforless.com/ignition/EEConomizer.gif

    I tried to maintain the factory pinout as much as possible so it would be plug-and-play in the car. The injector wires (58 and 59) were repurposed for an air/fuel meter and economizer light.
    Last edited by mrriggs; 09-02-2017 at 11:39 AM. Reason: Updated schematic

  17. #17

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    The circuit board is done.



    Notice all the header pins scattered around the board. Those are the wire-wrap points that will tie to the 60-pin connector.

  18. #18
    FEP Super Member xctasy's Avatar
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    Nice work.

    The 4180C EGR spacer and fitting was pretty tight on the 5.0. Its really a 460 4-bbl carb on a modified 1965 4 bbl 289 intake with the water crossover that makes everything so cramped. The EGR spacer, well, Ford had about six "goes" at the 4160/4180 spacer, each one different between the Big blocks and various small blocks. The aftermarket 8053 Edlebrock spacer doesn't help fit the carb, but the EGR parts are a combination of cast iron EGR mount.



    Can you confirm the Escort white box part is this, with the cast iron curved Delta pressure Feedback EGR nipple connection?


    The only thing I found was SMP EGV461 EGR Valve Fits FORD & MERCURY L4 1983-1987








    The 1983 -1985 Ford 4 Cylinder EGR Valve Mustang Escort CX-966 E4FZ-9D475-B only has one vac hose.


  19. #19
    FEP Super Member xctasy's Avatar
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    Your lucky you don't have to calibrate the system for an O2 sensor like I do.


    I decided back in 2012 to make a primary light off Turbo 4-bbl In line six, and have the air fuel delivery run off an emissions legal EECV with a speed density conversion.

    The combinations and permutations and inability to hard form a EGR system has kept me dormant on this project for a l-o-n-g time.

    I guessed that with Fords 4v 5.0's not being actively computer managed, it would be just like adding a Paxton Blower to a 1985 5.0 4V, like Saleen did. How wrong I was....the 1978 to 1985 Fox emissions packages are just a purgatorial pain in the aspidistra.....

    I've got a primary light off catalyst, and have been trying to duplicate the 5.0 system with a load control valve to use one light off cat during warm up, just like the Carb 5.0 M codes.


    I have been working since late Dec 2014 on an electronic Upstream Downstream Secondary AIR system on my 3.3 engine. It has to use two EGR valves, as its a sepErated 4-bbl on a in line six. Initially, I looked at reworking the non OBD EECV computer from our Aussie in line six, but the EGR code was a bit beyound me, so I've gone back to a 1-BBL FeedBack EECIV system from the F150. The EECIV CFi lookes like it could work, but its got an electric fuel pump relay, and I'm not going electric fuel pump.


    There are a lot of 1983 to 1994 EECIV systems that can take your EGR system. I really like what you are doing.

    I left the EGR to last, because in line sixes are just so difficult to package.


    Ford was forced to just keep adding things every year from 1980 to 1983.

    The sometimes included, sometimes not secondary AIR system is one bad thing to package.

    Some cars, secondary AIR,


    some not.



    First year SROD 3.3, had no secondary air Diverter valve.



    Then 1981 autos, Diverter valve got added




  20. #20

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    I have a Tomco 10420 EGR valve. It fits but I'm not sure if I'll use it or not. The pintle is just a flat washer and not a cone. Seems like it would be on or off and not provide much regulation. I got the CFI EGR valve with the harness I bought, it has the cone shape pintle and no internal backpressure transducer. I'd need to make a spacer plate with the PFE nipple or press a restrictor into the carb spacer and braze on a nipple. Not sure which way I'll go yet, still a lot of work to do before I need to worry about it.

    The kids go back to school tomorrow so I didn't meet my deadline. I got a second car that I can drive when I tear this one down. That took the urgency off of this project so I've just been working on it off and on.

    I'm still in the bench testing phase.



    All of the sensor inputs are working properly except for the most important one, the PIP. The hysteresis buffer is butchering the signal and the program that worked perfectly on the breadboard is playing fits now. One step at a time, it'll get there.

  21. #21

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    I was trying to keep things simple by using one of the opamps as a comparator for the PIP input. Unfortunately, an opamp hangs out in the linear region for far too long so the square PIP signal was fed to the microcontroller as a delayed trapezoid. I added a real comparator chip to the board and now it switches FAST! Faster than my scope can measure. The signal fed to the microcontroller is now a perfect square-wave representation of the PIP signal.

    The schematic link in a previous post has been updated to reflect the changes. The comparator has a few more connections but is otherwise the same as the previous opamp layout. I also tweaked the feedback resistor values a bit to better match the hysteresis of the TFI module; 7 volts on, 5 volts off.

    With that resolved it was on to debugging the code to figure out why it wasn't working like it did on the breadboard. I never tested any of the sensor inputs on the breadboard so I tried firing up the ECU with just the PIP input and it worked. When I hooked up the MAP sensor it freaked out although it was reading the MAP sensor correctly. After HOURS of testing I finally figured out the problem. IT WAS A TYPE-O! I typed 'clr' instead of 'clrb' on one of the instructions. The biggest frustration with computers is that they will always do what you tell them to do, not what you want them to do.

    Its working pretty well now but I still need to test the EGR function. You know, the thing that led to this whole can-o-worms.

  22. #22
    FEP Super Member xctasy's Avatar
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    Ahh,





    And Yep, that's electronics, and why we use teams of people to help trouble shoot code. Like the NASA engineers who checked the ill thought of throttle jamming US Toyota Camry electronic accelerator system.

    I went back to my old Jag XKE import photos.






    And tracked down an EGR heat stove proposal. This was just a heated intake, not the full EGR system.

    I would like to use your system, but I haven't scoped it yet. Popcorn icon, and good fortune man. Nice work!

  23. #23

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    After several late nights of testing and debugging, this thing is working well enough to put in an actual car.

    Here's the code; http://www.gofastforless.com/ignitio...omizer_ECU.src

    Unfortunately, I won't be able to do the harness swap on the LTD until I can get new tires for the van so this project has once again stalled.

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