I'm putting a 95 5.8L into my engine bay that used to have a 5.0L in it. Both are MAF. The bigger engine is running fine, but I'm concerned that the WAY1 EEC-IV is going to have different tables, especially the "load tables" than it should be using. It will be calculating the injector pulses based on the MAF sensor combined with speed of the engine, combined with what it thinks is the volumetric capability of the cylinders, right? So it will be slightly off, isn't that right? Or will it "just work" because it's MAF? anybody know this for sure?

 

It'll work fine one the 5.0 PCM has had a chance to adapt to the bigger motor.. which it should be able to do within a few drive cycles. As usual do not change any wiring under the hood of the truck receiving the engine, use all the 5.0 wiring and also make sure you use the correct flexplate or flywheel for your trans, that means if you are using a 4R70w DO NOT use the flexplate currently attached to the 5.8.. it will destroy the trans the first time the engine is fired.

 

It *does* work fine, but I can't tell if it's running "as good as it can". It idles nice, it feels only the slightest bit boggy as I'm accelerating, and at highway speeds, it sounds stressed out, but not too much. Runs far better than the 5.0L I had in there, which constantly felt underpowered.

But - it's been more than one person who has said it will run "better" if I adjust the load tables in it for the air/fuel calculations, that it's set right now to think it's got the 5.0 in it and uses that. I don't intuitively understand how it will run "different" if it had the right values... Let's see, quick walk through this mental exercise. MAF says "I'm getting M mass of air", VSS (vehicle speed sensor) says "I'm going V miles per hour". It looks up pulse width from table for injectors and sends that, which is coincidentally too little fuel for 5.8L. So it runs a bit lean. I guess the EEC will correct for that (within 12%) and make it run right? Problem is 5.0 vs 5.8 is already 14% change. If it always needs to correct by 14%, and the EEC can only adjust trim by +- 12.5%, then it's always at the end of it's correction band, right? No room for making more corrections to take into account random driving issues...

I didn't change any of the wiring... But I did keep the 5.8L's flex plate on it. I was told it was balanced for the harmonic balancer on the front of the engine, and to keep them as a pair. The transmission is an E4od. I very much doubt anything will destroy THAT damned thing. it's huge and heavy.

 

The pre programmed tables are just the starting point, the computer will make adjustments and store them for future use thus building up a new set of tables customized to your engine. If the computer runs out of adjustment room you will get a code for it.. it'll be something like.. "O2 always lean... PCM at adaptive limit". An all stock 5.8 doesn't make any more HP than a 5.0 so fueling requirements aren't that different, but that also means it's somewhat understandable if your truck still feels a bit underpowered. There is lots of room for improvement though and you should be able to take advantage of some of these upgrades without any external help from tuners.

OK you got lucky on the flexplate, the only trans used with the 5.8 was the E4OD while the 5.0 usually came with a 4R70w but could get an E4OD.

 

Yeah. At least I was smart enuf to match transmission for transmission! Honestly, I got super lucky. When I bought this bronco, the 5.0L in it was burning water (white smoke, a lot of it). I took off the valve covers to take a look, and in the process found out the entire engine was full of gunk. burned up, fouled air intake, fouled up throttle body, burned up valves, goop all over the valve rockers, the list goes on. Basically, just crapped out. So I searched around the bought this 5.8L from a junkyard, B&R, down in Oregon. For $500, they delivered the engine right to my door. I was going to buy a reman, but I had a lot of suspicion about how good the work is, or how much attention to detail they get. When I got my engine, I stripped it down to the block and took the block + parts into a machine shop. They looked at it and said, "Jeez, this thing still has the factory hone marks on it, it's in GREAT shape. This engine is mint!!!" I was delighted. While I had the engine out, I tore apart the E4OD myself, thinking, "I'll rebuild this from the ATSC manual" and watched a bunch of youtube vids. I'd say in retrospect the transmission was MUCH harder than the engine, but only because it has 869 pretty damned important parts in it, and the engine, about 80. Heh.

... wait... what? A 5.8 doesn't make any more HP than a 5.0? Didn't know that. How's that rule of thumb go? Deeper bore = more torque, wider bore = more HP?

I've redone a LOT of engines, but I've never done any mods. Always stock. This Bronco, in any case, is a car for my kids. I wanted a "tank" for my beginning drivers (age 16 and under) to "learn in". My 16 year old changed lanes the other day w/o signaling, and almost totaled this Volvo that was speeding when he shouldn't have been. The look of utter fear on his face that this Bronco would have ground his pretty car into little Volvo chunks was (hate to admit it), a bit funny. My son, meanwhile, got quite the lecture, and now I will not go in the car w/ him for the next 6 months.

I'm still stumped about how the 5.0 computer can build up new, workable, tables and not run out of adjustment room. Interesting... wish I knew more. too bad FordFuelInjection's gone. I'd like to know more about how the EEC-IV's work, but the stuff that I've found online is mostly OP-codes and schematics, not "theory of operation" stuff.

Not going to buy a Quarterhorse or Tweecer for this daily driver for my son. Not until I inherit it back again and if I want to keep it working at that time.

 

Here is a link to some info on the eec4 pcm..
Pete Kvitek's EEC IV page

 

Invalid link. Many of these links aren't valid these days. Sad old broken internets.

 

The link works ok for me. As for the fuel tables, think of it this way: the mass air sensor tells the ECU how much air is entering the engine. To achieve the desired fuel mixture, it has a lookup for RPM and air mass. For the same RPM the 351 should be farther up the table in terms of air mass, so the fuel lookup is therefore higher to maintain the desired ratio. Engine size is fairly irrelevant when a mass air sensor is used, at least in terms of fueling. When you get outside of the table's programmed range is when there are problems. Spark timing may be slightly off, though, if the spark table is based on mass airflow instead of throttle.

 

Spark table is load(and RPM) based and load is calculated directly from MAF input so again engine displacement doesn't matter.

 

From a "will it run?" perspective, it doesn't matter, but from an optimized ignition advance standpoint, it will not be perfect.

 

conanski


so i can swap in a 5.8 into a 95maf with a 4r70w? aslonv as i change the flywheel on the 5.8. will the 5.0 flywheel bolt onto the 5.8

 

Yes the 5.0 flesplate will bolt on but it's the wrong counterbalance weight, you need a 28oz flexplate for an AOD/4R70w. The 351/AOD combo was used in the mid '80s crown vic so that is what you need to order.