Will, as I recall you are using an 87 wagon 5.0 for your EFI swap. Another rather interesting tidbit I learned today, while trying to get a 69 EFI Bronco going, we found that the nonHO motors have different injectors than the mustangs. Ford color coded theirs with the 19lb injectors having a yellow-orange color. He had switched to mustang components which were not matched to the grey colored injectors he had. I assume his were less than 19lbers. If you do this swap stick with all of the components from your donor vehicle to get it running. After that, start making changes. Just thought you may be interested. After the non HO vs HO fiasco with this bronco I would recommend finding an HO donor as opposed to piecing it together. Good luck
The non-HO motors also fire the injectors differently. Maybe bank-fire 'em, I don't remember. Some years ago, I swapped an HO motor into a Bronco, and had to do some SERIOUS wire harness work. The owner who I did the work for has now sold it, so I pity the fool who may have to troubleshoot it in the future!
motorhead, the non HOs fire the injectors in the 302 firing order while the HO motors fire the injectors in the 351W firing order (as required by the valve timing of the cam, acutally, it is the computer that determines the firing order). I also believe that the non-HO motors may have "smaller" injectors due to the fact that they are a different color. That is the info I was trying to convey. Yet another reason to stick with HO or nonHO and don't mix the two.
In the 85-91 E/F trucks, the injectors are batch fire meaning 4 at a time. A look at a drawings shows this.
I would like to add more to this subject. The non HO motors were all speed density controlled and did not have sequencial fuel injector control (SEFI), only batch fire. Some of the Lincoln cars of the late 80s the exception. The injector size of 19 pounds per hour is pegged to the displacement size (302/5L) and would not change from engine to engine for fuel requirement reasons. The 351 FI engines have 24 lb injectors. Today there is a large selection of injector sizes from 19 all the way to 50+ in smaller increments for custom fuel midifications to dial in on super charger application requriements. When doing changes such as a 302 fire order, the computer wiring has to be change to accomadate the engine. The changes depend on the computer used. Could be batch fire, SEFI and then either Speed Density or Mass Air (MAF).
KM, if all nonHOs are batch fire I'm not sure why switching four of the injector harness wires (pins) allow you to switch to HO. I have that harness installation pamphlet from ford and they simply say switching four of the pins will allow use of the HO computer with the 351W firing order. Also, they used 24lbers on the 5.0 cobras. I guess I'm not sure if I really understand batch firing. The fuel needs to go in at a particular time or it will not run. Do you have any info as to why the injectors on nonHOs are a different color? The jump from a 50mm tb to a 58mm tb is potentially a 25% increase in air flow. That represents the non HO to the HO. When jumping to the cobra (65mm tb) you gain another potential 20% in air flow. I would assume that is what requires the different injectors. What are your thoughts?
Swapping pins is all it takes. I've done it before on a customer car when they swapped in the wrong motor. However I am almost positive that the Ford full size Ford motors are SEFI even though they are not HO. I'll do some checking next week.
First off 'if' the wire harness from the plug to the injectors in the engine bay are wired as batch fire, changing them at the ECM would not work if the injectors are wired in two groups of four. Its posssible that some harnesses are wired as individual leads passed the plug, then it can be done.. You would need to start with SEFI wire harness to be able to change from the old 302 fire order to the later fire order of which only 4 pins would need to be changed at the ECM. The fuel injection timing is not as critical as you may think as long as it is stays around the time interval of the intake valve opening. To get the most from the injector timing, the SEFI times so the injector sprays against the head of the open intake valve. In batch fire injection, the cylinders groups are selected that will be close on there intake valve timing and the injectors can actually function just ahead of the valve opening. Makes little difference in normal engine running. The Cobra uses a Mass Air meter calibrated for 24 lb injectors to allow the engine to make more power and support the upgraded power level of the engine. Fuel injectors are normally run at a fuel pressure of 40 lbs. As an example, 19lb injectors at 40lb fuel pressure and 90% duty cycle will support HP level of about 30 hp/ cylinder x 8 before going lean at BSFC of .50. You can see that the factory would have to increase the size of the injector in order to keep their operation duty cycle in the 10 to 90% range. Not only is the injector size in relation to the displacement but also the power level or air flow. Then there is the lookup tables in the ECM that need to work within there range unless altered by a chip or other reprograming methods. In my earlier post I was refering to stock engines using the 19 lb injector. The 85 pickup has a batch fire 302 rated at about 145 hp and uses a 19 lb injector. Going beyond, a little, when an engine is supercharged aftermarket, a device call an FMU is plumbed into the outlet side of the fuel rail to backup the fuel presure to a higher psi by a boost sensitive FMU. This enables the injectors to meter more fuel within limits. The fuel pump's ability to pump fuel at the levels needed, also becomes an issue. A 19 lb injector can be made to flow nearly 24 pounds per hour and could feed fuel to support 270+hp at elevated fuel pressures of 60 lbs.. The factory has to use injectors that will flow enough fuel and still stay inside the HP rating (air flow) of the engine for complete driveability, emissons and marketing. As for colors, it's hard to say how much it means in IDing due to there different sources. Sometime yes sometime no. Many of the Ford cars of the last few years now use a single fuel line and a pressure sensor to alter the pump speed. Moding this setup to flow more fuel is done a little differently. Make no mistake, this is complicated until one get the relationships. You should see what some people do with this on other boards and cannot figure out why they have problems.
Some have asked why I went bone stock to initially install the EFI. I think this is just another case for taking it one step at a time. I assumed the batch fire was after the exhaust valve and anytime during intake opening. Seems a little odd. I would think there would be some advantage to SEFI, maybe not much. My next move is to go with a complete cobra setup including the cam, computer, and etc. I know the non HO injectors are a different part number than the HO injectors when ordering them from a local vendor. Is it possible that batch fire had one color and SEFI another? The EFI bronco I'm helping a friend with still runs like ****. I'm trying to get to the "root" of the problem, the mix and match is likely the problem. KM, maybe you would have access to this info, I've heard that the cobra MAF is actually calibrated for 19lbers but the computer is designed to compensate. Any info on that?
I don't know if that is the case, about the Cobra, but as you stated it, it is possible to do that at the ECM level as long as all the dynamic functions are met.. The factory does things that are the least costly. I don't follow all these things real close. With the existing systems we try to use, the injector / ECM / engine and application has to match as far as fuel requirements go. The system you have problems with, needs to know if is speed density or mass air, how the Map is hooked up and make sure the EGR is not plumbed up to keep it open all the time. That sure will create a big idle problem. In mass air the Map become a Bap. The difference is that in Map use, it is plumbed to the intake vacuum source. Used as a Bap, it is left open to air.
It's mass air with a BAP. THe EGR is blocked off! It is a mustang setup with the computer, intake, injectors but a moderately larger cam. It started out as a late 80's Marqui with speed density, then it was switched to mass air with a conversion kit and then the mustang goodies were added later (including intake, injectors, wiring harness, MAF, TB, EGR spacer, and the above stated mass air conversion). KM, now that I think about it, the plate on the intake said 5.0 SEFI, not 5.0 HO. So perhaps Charlie was correct in stating that the large autos had non-HO SEFI. At any rate, we will need to work through each change.
