Chad, the cold start stratigy looks at the ECT and ACT to set fuel. The engine should go high idle and a timer count down begins, along with the value of the ECT until the ox sensors heat to about 600*, then the system goes closed loop with the OX sensors taking control from that point on. Look for a problem with the wiring, plugups and the IAC. Try doing a KOER test, this may pick up the problem. You can do your fuel pump setup but IMO you don't need the noisey low pressure pump if the hi pressure pump is located close to the tank. Hi pressure line from the outlet of the hi pressure pump to the fuel rail. Filter can be a stock FI unit or a low pressure type before the big pump. The VSS should be used because it plays an important part during coast down. It along with the TPS closedown, tells the EEC what is going on. This closes down fuel injection to a low level when it's not needed,closes down the IAC may change ignition timing and updates the EEC operating tables for smooth operation. When at a stop or low speed, the system recovers back to normal engine control.
Rick, when I bought the T-bird, it was not running. Man, I went thru everything on that fuel injection, trying to figure out what was going on with it. I spent probably 5 weeks studying that system, rebuilding everything from injectors, regulator, replaced the sensors, all new gaskets in the upper plentum, rebuilt the heads, you name it it was replaced under the hood. I had that system off an on that car about 50 times, looking for why it would not run. I could pour a little fuel into the throttle body, and it would fire up, and idle for about 20 seconds and die. I took a nail and pushed in the valve on the fuel rail, had fuel,, I finally said enough, and put on a carb intake. Funny thing,,, Thats when I found what was wrong,,,,, See, I had no mechanical pump for the carb,, so I hooked up the line out of the tank, the pump did not over power the needle seat and flood it out. was the fuel pump bad from the start. Lesson learned. I got a good idea on how the EFI works, when it was in the t-bird,, I wish now I would have pulled the tank and put in a pump. OH WELL!!! So, I put the EFI in a clean bag and put it on the shelf, till now,,, I know everything is good, and that carb I have is not good enough. especially looking at the efi lower intake, 8 holes to feed each cyl,,, that are actually larger than the butterflies of the carb. So it is starving for air in my opinion. I do remember how that engine would roar when I had fuel dumped into the throttle body. Sounded real good. As for how fast i work on the ol maverick,, well, I have a very understanding wife,,, LOL. Been thinking of calling the maverick, "the other woman" cause i spend alot of time with it. I have a large shop where I build pulling tractors, and once in a while, i get bored on working on them day in day out. It is refreshing to work on a car again. ChadS
Filter can be a stock FI unit or a low pressure type before the big pump. The VSS should be used because it plays an important part during coast down. It along with the TPS closedown, tells the EEC what is going on. This closes down fuel injection to a low level when it's not needed,closes down the IAC may change ignition timing and updates the EEC operating tables for smooth operation. When at a stop or low speed, the system recovers back to normal engine control.[/QUOTE] So if the system was a mass air, that would take place of the VSS?? ill keep the VSS,,, just have to wire it. Im good at schematics,, and Im running the wiring down to the VSS. I know the engine will run without the dashboard,, so, it should run with out the guages and have no trouble,, I have manual guages to monitor oil pressure, and water temps. all the sensors are still in place though,, Right now, I have the EFI on the engine, Im mounting the computer under the dash, I made a box to protect it, and made a rubber pad for it to rest on. All the wiring is hooked up on the engine, but I have not got the power hooked up to the computer. ran out of daylight, and my back was killing me,, ya know,, after some measuring,,, out front of the engine,, may be enough room for a turbo,, seen one setup in a Ford magazine,,, thought that was sweet. but,, maybe years down the road.... Chad
Both systems use VSS signal. All the latest cars and trucks still use it. In the case of integrated cruise control, VSS is used for very precision speed control as opposed to the stand alone type usually used and is not quite as good. I would get the book on Ford fuel injection and learn all the sub systems' operations to make your hobby go much smoother when trouble shooting and modifying.
Will do sir! I made the mistake before I decided on EFI, of cutting the alternator wiring from the harness to try and wire it up into the maverick harness. Now, Im not too sure where the alt wiring goes into the computers harness. I went to www.fordfuelinjection.com and got the pin diagrams, which helped, but wish they had a color coded, more elaborate diagram available. (sighs) I should have made this decision weeks ago before I cut that part of the harness out. 2 lagre wires at the end of the harness,,,,, larger wires,,, Im wondering if one is the key power on, and the other hooks up to the charge/distribution wire off the alternator,,,, Has ayone thought of building their own upper plentum for clearence reasons, out of sheet metal? Just a large box, and set the throttle body on the intake? maybe even multiple throttle bodies?? Hmmmm,,,,,, ChadS
I layed out the wiring harness, and the EFI,, I did learn that the 2 plugs in question were infact to the switch, and the guages. Does any of these wires have to be hooked up to run properly, other than the key switched power,,, Im wondering if the Speedo sensor is in that plug too,,,, Im gonna hook everythng up to a battery, with the distributor out, everything hooked up,, except the alternator, and the fuel pump, to see if I can get the igntion to fire the coil, and fire the injectors. If I can get that far, that would give me some hope!! LOL! Chad
Just an f.y.i. A problem I ran into was that the FP was getting a signal at Key On and Start but after the key released back to the "run" position - no fuel. It took a lot of trial and error for me to find the problem (actually put my hand on the FP during the cranking process to finally learn that was what caused it to start up then immediatley die). I dunno about the connectors you're describing.
Fuel pump operation for fuel injection is initially started at power up thru the ignition switch. This pulses a turn-on on circuit in the EEC that last about 3 seconds then stops the pump. This is to prime the fuelrails enough for starting. At cranking, the PIP sensor becomes the reference signal for all operations and along with triggering the fuel injectors and ignition, also pulses the pump turn on circuit and keeps the pump relay powered up full time. It is designed this way so in event the engine stalls, accident or other events ocurr, that the pump doesnot continue to pump fuel and feed the possibility of a fire. That is also the reason for the inertia switch in the pump circuit. For alternator and battery capacities, the alternator should be sized at least 90 amps with a battery capacity in the 500+ cranking amp range. Reason is the FI system in total consumes about 14 amps full time running and is about double that of the old system plus nite running and heater/ac use then add more if an audio system is also being used.
I see what your saying. There is 2 relays on my harness. one under the hood, and one in the trunk of the t-bird. Close to the computer, I picked up the wiring to the fuel pump, and the under hood relay is still attached in the harness. I remember, the under hood relay only kicked on when the key was first turned on, 3 seconds like decribed, and shut off, soon as the engine turned over the relay in the trunk turned on. is the under hood relay,,, for the power up mode when the key is first turned on only? if so, and I can get away with running the existing wires to the pump, Ill hook up the inline pump off those wires, and be just like the factory set up,,, once I figure out why there is 4 wires going to the pump,,, I suppose 2 are for the pump, and the other 2 are for the sending unit, or from the relay under the hood, telling the second relay, power is on, and awaiting engine rotation to activate the pump continuously. Did you guys take a stock harness and make it work, or use a custom made harness? if you used the stock harness, can it be thinned out to the basic componets of the SEFI? Rick, the 2 connectors i speak of, are the wiring that go into the dashboard,, that have the temp guage, oil guage, amp guage, tach, speedometer, (I think,,) A/C, cruise, ign switch, My haynes manual on the t-bird sucks, all it shows is the run/start diagrams, charging diagrams, and nothing on he dash, computer, well the actual part I need to know. Ive been on ford fuel injection . com for about 3 hours reading tech articles, and seen that harness he built. im wondering if he took that from a stock harness,,, or its custom, prefabbed. I went to my cousins house, which he had another 88 t-bird exactly like mine, and I got the SEFI manifold and plentum, complete. I think what i will do is wire it up outside the car, on a bench, I have a SEFI distributor, and coil, and a good hot battery. if I hook everything up correctly, I should be able to turn on power, (when I find the key switch wires) and rotate the distributor and hear the injectors fire, see the coil fire, hear the fuel pump relay kick on and kick off, and if I had a pump wired to the fuel pump I could hear the pump run while the distributor is rotating. The, if all that works, Ill documaent everything I learned,,, install it in the ol 69.5 maverick, install the fuel pump, and return lines, and cross my fingers to hear it fire up, it should idle, then figure out where to find the schematic for the VSS so it can be driven. Sounds almost too good to be true huh???? Did you guys thin out a stock harness, or buy one? ChadS
If you look at pin 22 off the EEC and follow it, you can see it goes to the Test connector, and the Fuel pump relay. This is where the ground comes from to operate the pump circuit for inital pre-cranking and after cranking begins. In a completed circuit you can ground the test plug pin and run the pump full time for testing purposes, testing fuel pressure and pump operation.. An ohmeter check will tell quickly if the EEC is putting out a ground in pre-crank mode and when cranking begins. You should be able to thin a stock harness for you application.
WHEW!!! last night, i took all the snakeskin off the harness to label all the wires and try to thin it out. From what I seen,,, I cant thin it out much!! Bout every wire is used comming from the computer. Ok, there is 3 main hot wires, and 3 main grounds,,, The 2 plugs I mentioned before is where I can patch into the wiring harness to hook the key switch up, the rest of the 3 hot wires appear to be constant voltage, and the wires into the plugs, actaully switch power to the computer and activates. It took 4 hours to label all the wires, and document them all, but I got em! All 60 pins, even though, some are not used,,, My t-bird is a late model 88,,, are these computers the same as the newer style?? ChadS
Your question about the EEC differences are that yes there are differences in options, timing curves vs weight, and in genral applications year to year and car to car. The good news is a large number will plug up and be useful providing most of the same supporting hardware is used with it's original application. Some examples are manuel/auto application has wire differences as well as timing curve differences as use in the same car model. Then differences in cars of different weight etc.etc. Trucks use knock sensors where most auto applicatons don't. Major difference between SD and Mass Air is the method used in measuring engine load requirements. Yor system uses a MAP sensor measuring intake vacuum where as the Mass A ir uses an air flow meter in the intake duct to the throttle body. Tis make the EECs different in that repect. Finally, the same general EEC design is used in the 4, v6, and v8 up to about 93. One thing you have to address is the neutral start switch configuration for your application.
(I was sure I replied to this earlier this morning - must've been before coffee). I used a 1990 Mustang 5.0 Automatic as the donor. A buddy of mine, who is way more familiar with wiring than I am, came over and removed about 75% of the wiring harness that I'd pulled from the car (I'd pulled EVERYTHING). Over a few beers and a couple hours, he turned 20lbs of wiring harness into about 5lbs.
My eyes are crossed!!! Ive been separating plugs, marking wires on the plugs and computer plug. Lightening up that harness. I wanted to just cut the wires bout 7 inches past the computer's plug,,, HAHAHA,, but I dont think that was a good idea. So I cut the plugs off bout 10 inches wire left on em. Dont worry, I labeled, and wrote down exactly where each and every wire went to. So far, I got the 2 big plugs, (black n grey) that hooks up to the injectors and the manifold parts,,, MAP, test plug, and the AC-wot, ac off, and that relay under the hood, Im thinking that realy may have nothing to do with the fuel pump,, has to be the AC relay,,,, I had to walk a way for a spell from it...... whew, lot of wires. but not too bad,, ChadS
