As of the moment I am restoring a 1972 2 door Maverick with an all original 302. I was wondering what it would take to replace it with a EFI 5.0 (preferably from a 87-93 Mustang) has anybody done this recently and if so how hard was it to do? Thanks for your time Andrew
Several here have done it... Ken Merring and GS Johnson in particular that I know of. I am not familiar with the newer stuff enough to tackle such a project. Check the archives for previous posts.
Here is my advice on how to procede with that type of conversion. First study all about how the fuel injection works. This prepares you for knowing all that the conversion requies, enables troubleshooting if and when something doesnot work. After you are done with the project, you have to be the expert because there is no shop that would try to work on the fuel injection unless your lucky to some extent. Basicly, the 5L engine in your car needs to have a new fuel feed and return pipe system with its's hi pressure fuel filter. An in line hi pressure fuel pump, control relay and some means of fitting to the fuel tank. At the engine, wiring to the computer, change of alternator or use the late model one with the engine getting rid of the external regulator. Move the battery to the trunk and run new heavy wire. This makes room for the air filter housing at the old battery location. There will be the need to build firewall to spring tower braces as the stock ones would hit the upper plenum manifold. Power steering can be an issue. Shorty headers from Hedmon, is the easy way to do exhaust and get the oxygen sensors up close to the engine. If keeping a C4 auto trans, the flywheel needs to be a 50 oz. balance with 157 tooth ring gear to fit the 5L engine to the C4. The auto kick down uses the AOD- TV cable with a special lever on the trans. Beyond all this is just attending to all the small stuff. Then later when you recover from a low wallet, consider a Kenne Bell super charger and it's instant tire smoke at the touch of the throttle in 3000 lb car. I did the original 302 retrofit to EFI so there are other diffferences if that is done. Good luck.
I thought I would mention the Kenne Bell at the end because it just makes a monster out of a 5L/302 engine for street use, right off idle even at 6 lbs boost. I am going to write a paper about tuning an engine with one of these on because I am doing just that at the present time with the speed density controlled Lincoln. Making the tuning changes and testing the results to varify how to adjust the fuel curve from idle through cruise and mid rpm power response, for the base fuel setup. This involves the ACT, ECT, and an adjustable fuel pressure regulator without doing any computer table changes. The fuel mangement unit takes care of it's self for wide open throttle. I am backing down the fuel curve to see where is starts to cause operational problems just to get the information. If, one day I get to find another unit for my Comet, I'm fool enough to put it on just to do it, having done so once already. It will fit under the Comet hood in place of the upper plenimn.
I told you so..... ....that is why Ken wears pocket protectors sporting a slide rule and dial caliper and I wear surf T-shirts. I grew up in the old school of carburetors, I still don't know the difference between mass air and whatever the other type is. Seth
How did you know that? Pretty good guess. Years ago I did use those tools and still use various tools today, to do machine work and layout for parts and repairs for auto and even some gun smithing to make parts for the antique guns I get at times. Come on, get with the show and put them carbs away. The difference between Mass Air and Speed Density control systems is the way engine load is measured. Mass Air uses a metering device in the intake to measure air flow for load while Speed Density uses a manifold vacuum sensor to signal the computer of the load and runs more on computer modeling and comparison to tables than Mass Air but still both system are basicly the same with these differences.
Ken... I work with 'techies' all the time! They are easy to spot! I had thought that one of the types of efi systems were much more difficult to work with when modifying other parts of an engine, such as increasing compression ratios etc. Doesn't speed density put limitations on performance given increases in output potential in other parts of the engine when compared to mass air? Also, you made a statement contrary to my thoughts. I thought that if I dropped an '89 EFI H.O. 5 liter into my Comet GT, that I would have an easier time finding a dealer or mechanic to work on it. Provided that it is not a mixed bag of parts from various vehicles or year models, I would have felt more comfortable hitting the road going to say the 'Roundup' and having problems along the way. I figured that I would be much more likely to get assistance with that setup than with the original setup modified with various over the counter hot rod pieces. Hmmmm?
Take a Maverick with a fuelie 5.0 to a Ford dealer or repair shop around here...and they'll send you out the door. They don't work on engine swapped vehicles, but I don't know how they do it in your area. The only problem with speed-density is that the engine can only supply the correct amount of fuel in relationship to what the factory programs into the computer...it cannot adjust to changes (specifically with modifications that change engine vacuum.) Mass-air directly reads the amount of air going into the engine, and adjusts timing and fuel delivery proportionately, but only to an extent. After a point, even the mass-air systems need tweaking to the computer ($$$). Everyone says speed-density will not make as much power...but that is BS. Why does F.A.S.T(formerly speed-pro) electronics use speed-density type systems. Also, if you were to compare 2 mustangs, say an '88 model speed-density and a '89 mass-air, the speed-density one will have more horsepower due to less restriction in the intake tract (the mass air meter causes a restriction.) Just my thougts on the subject, FWIW
Yes, all the after market fuel injection systems are a version of speed density. The advantage is all the features are adjustable in the ECM by lap top. You ask about the limitations of factory speed density, it is mostly the Map sensor derived load signal. The cam has to maintain high manifold vacuum the way the sensor expects to see it and provide this conditioned signal to the ECM. The cam needs to have lobe centers from about 114* upward with the (effective) overlap near zero degrees to satisfy that requirement. This is the largest drawback to modifying speed density by a cam change. There are a few cams that can be used on a speed density motor to enhance performance but the tuning required starts to get precise in order to make them reasonable in drivability. With my super charger installation, the Map sensor has to have it's vacuum line controlled by a boost activated switch assembly to take the boost pressure off the Map because a pressure signal instead of vacuum drives the ECM into some funny gyration on the fuel tables. It is at this point that the fuel mangement unit takes over to supply the extra fuel needed for power from the air forced into the engine and keep the air/fuel ratio in the 11 to 12 to 1 area.
Huh ???????? That is exactly why I have a Holley 600 !! I recognize some of those terms, I became disgusted with computers, map sensors etc. when I owned an SHO. I loved the way it ran, but what a mess to work on when it goes awry. I would like to take some classes on modern stuff. My Dad was a mechanic in the military for 35 yrs. Everything I know I have learned from him over the years along with my own tinkering. I just haven't tackled any EFI systems on modern V8's. Seth
Seth, don't be intimidated by efi. Taking a class is a good idea, but perhaps the easiest way imo is to pick up an 86-93 fi mustang gt. The efi is VERY basic and extrememly easy to work on, the computer on my 86 is so basic there is no check engine light. I would suggest those engines as a good starting point, they are very basic.
Ken You specify Hedmen Shorty headers in your post. Do you have a part number that you know works? I am getting ready to drop my '89 Mass-air 5.0 and AOD into my '69.5 and am needing to figure out O2 sensor placement, etc. Decided to use the Painless wiring computer and engine harness. Can't find a gas tank to fit mine so if I can't manage to repair the 3 1" or larger holes poked into it by the salvage yard workers, I will just fit a fuel cell instead. Found a set of really nice bucket seats out of a late Probe so those will replace the stock bench seat. Completely replaced the front suspension except springs. I am looking for a set of progressive rate springs. I would guess that a set for a '67 or '68 Mustang should work about right for spring rate and height. Still looking for the right combination for the rear end. I have a Versaille 9" with 3.79:1 and Discs but it is currently under my '70 Mustang. Don't know if I am ready to move it yet. Have the complete A/C from a '76 Maverick including all brackets, hoses, and vacuum lines. I am planning to use the '89 Mustang compressor so will have to have hoses modified to mate up to the newer style compressor. Quite a project but I already have most of the major parts in the garage. (It's all the little things that will make the project take a long time and cost a lot of money.) Thanks in advance.
Check out the Hedmon 88400 shorty headers. They are made for the early Mustang but will fit the Mav/Comets. I don't know what outlet/head pipe clearence changes might have to be made for use with an AOD as that trans is a little bigger than the C4. I have the c4 and made an outlet direction change so there would be lots of room and easy to work on. Some have used them as is, so you can see there pretty close in fit. There are no unusual plug changeing difficulties or starter problems. Put the ox sensor bungs up close to the header connections. The pipes will have to be custom bent to come down to your mufflers. I have a custom X pipe assembly. Everything should be made up so there are hardly any pipes seen from the side of the car. The outlets from my X, tuck up into the driveshaft tunnel close to the drive shaft and hit the mufflers that fit into the areas just ahead of the axle. Takes some engineering but all comes out very nice. One more thing, these headers do not interfer with power steering in any way. No cylinder dropping as needed with long tubes.
Thank you VERY MUCH for the part number and information! This is exactly what I was looking for. The exhaust was the last real subsystem that needed figuring out. The rest is just time and effort.
