Soliciting help here from a Ford engineer or EEC jedi. I am starting a new project and need help. The EEC is going to be the critical part. Here is a rundown for the project as planned.

1972 F-250 Sport Custom just purchased. Will be converted to 4x4 with Dana 60 front and rear. 2 NP205 Xfer cases inline for 4:1 reduction. Front case front shaft runs pto hydraulics for welder, winch, genset, compressor and rear case running drivetrain. Thats the easy part. Now to the motor.

1970 D0VE block 460 worked out to 557ci. w/girdle. Motorsport SCJ Alum heads. Medium to rad cam grind (282/292) w/ full roller cam bearings and lifters. 10.5:1 compression. Possible home made long runner intake plumbed for SFI (Just started welding Alum so will see how well I do at it). I am after brutal torque and pulling capability here. HP is nice too, but not the objective. I want GRUNT......

My baseline EEC build "from" point is a 1996 7.5L F-350 4x4 w/Cali emissions package(per alldata). Cali emissions is the only SFI, MAF and EEC V setup I find for the 460. I prefer this over MAP due to the engine mods, and flashability of the V vs the IV needing a piggyback chip, unless someone here is really savy w/IV and can totaly redraw the scalars, tables and functions from scratch. My concern comes in in the area of the EGR/MAF/HEGO.

1. EGR - It appears the EGR uses a pressure diferential sensing thru a restrictor plate. My motor build up will probably drive this ballistic due to pulsing in the exhaust. How do I work around this?

2. MAF - Same same here. Will the pulsing of the cam drive the MAF crazy?

3. HEGO - There are 3 HEGOS, 2 pre cat and 1 post cat. For a 72
we dont need no stinkin cats. What do I do here?

I really want the easy of start, reliability and drivability provided by EEC and the good idle and economy provided by SFI but need to overcome these and other obsticals. Any help will be greatly apperciated and EEC conversion stories from the trenches welcomed.

Thanks, Scott.

 

The pulsing shouldn't cause a problem, but tuning won't completely get around loping problems with the cam. Differant cam timing can be a problem with the stock computer.

The cat removal will cause a problem, throwing a check engine light and possibly putting the computer in open loop operation.

The best thing you can do is get a chip programmed to get it running okay, then do a dyno pull that includes air/fuel ratio graphs. This graph is the biggest factor in getting a perfect tune. Ignition timing shouldn't be a problem (pretty standard table information based on octane and compression). After the dyno pull, we "dial in" optimal A/F ratio and timing.

 

Thank you for the guidance. I really want the system to be able to function in closed loop at warm idle, cruise and mild acceleration. For cold start, warm up, gettin on it and WOT we are looking at going with maps of RPM vs TPS for engine load to control timing and set a base injector pulswidth (PW), and MAF vs RPM for a injector PW modifyer (+/-). We will eliminate the cats and 3rd HO2S behind the cat and use #1 (11) and #2 (12) HO2S to control closed loop operation, and eliminate the switching algorithim between the front HO2S and rear HO2S that seems to check for cat efficency. I believe the rear HO2S is pin 21 and we are going to set it up on a switch to run the motor at pto speed (1050 RPM) using a second modified IAB we will install behind the MAF and a longer injector PW. We are still debating the EGR issue. I am sure it will result in some hair loss. I want to use it but we need a different setup than the differential pressure system and different code and functions to boot. We are looking at the mustang EGR today as a possability but I do not know if I can make its functions work in the place of the 460's functions in the program. Any guidance on this will be appreciated if it has been attempted before. Also, the offset of the code in the EEC is not 0200 like my expedition. Any guess as to what offset to install the prog back to is a bonus too. Have a Merry Christmas Ken.

Thanks, Scott

 

Your best bet is to check out the Tweecer, it handles it all for you and has all the maps and flags already handled with a nice interface they wrote. Supports programming through USB and you can have more than one set of MAPs available and switch them on the fly.... Also, there is an EEC-IV mailing list - you may want to do a Google search for them. They've got a lot of information on hacking the PCM, but activity is slow these days (not as many hacking the older PCM's these days).

 

Looked at the TweecerRT. Unfortunately there is not a model to support my processor on the EEC V. Mostly just Mustang stuff. Just another hurdle we had to overcome. We used a Basic Stamp 24P to dump the code by triggering a reset. Getting all of the code back in there in the right spot is a future challenge. I'm a Network Security Engineer in the Navy, not a programer, so the learning curve has been steep. Thanks for the help.


Scott

 

Been down this road. You end up with similar issues when you go to 4-tube headers and the EGR is necessarily tapped off of one cylinder's header pipe instead of from the stock exhaust manifold.

First, the EGR pressure differential sensor doesn't seem to be affected at all by pulsing. Its feed is through a long, thin pipe which probably smooths out the pulses. Or the sensor just doesn't care. But in any case, non-issue.

What *is* an issue is a free-flowing exhaust doesn't have enough back pressure to feed enough exhaust back to the engine so there's marginal EGR flow. That *will* trip you a check engine light after a while. The "fix" is to put a calibrated air leak on the downstream side of the EGR differential pressure sensor.

In other words, since you can't increase the pressure on the pressure side, you lower it on the downstream side. Put a small brass 1/8" T fitting in the rubber line on the downstream side of the sensor. In one leg of the T put a 1/8" barb fitting that has had the hole filled with solder. Then start with drilling a 1/32" hole through the solder plug, which should provide enough of a leak so the sensor is fooled. If not, make the hole a little larger until the sensor *is* fooled. You cannot simply disconnect the downstream side of the sensor, however. That will cause the ECU to give you a "sensor failed" code. You've got to putz with it a little as I described. There is probably an electronic way to alter the output of the sensor, but without knowing what the voltage output vs. pressure is, it was a dead end for me.

No.

I'd simply install some oxy sensors. I've got one in each header collector and one post-catalytic converter. Other than the cost, no big deal. If you don't have a catalytic, then you'll have to get one of the "fakers" that are sold on the internet to deal with the post-converter one. (For use by people that have removed their catalytics). Popular with the Mustang jocks.

But another caution applies. Keep the sensors as close to the engine as you can, not way down the pipes. If you don't, then you get a "slow oxy sensor response" fault. The ECU expects a fairly quick response out of the O2 sensors in response to engine operating condition changes, putting them a long way downstream delays their response.

That pretty much sums up my experience on my truck. It is a '96 F-250 7.5L MAF EEC-V that I purchased from someone that moved here from California. Made a lot of mods to it, it's a fantastic truck. Except for the 10-11 MPG part. ;-) My wife drives it more than I do to tow her horse trailer. Me, I sdrive the PSD most of the time these days, it's my work truck with all my tools.

Good luck. I admire your fortitude in making all of this work.

PS- You might want to post your questions on the 460 forum, there's a dude named Dennis (IIRC) that really knows his way around the EEC-V controlled 460s. I don't know if he's still around, or if he's into diesels these days, but do some digging in that forum with a search for past postings concerning your questions. I found your questions here pretty much just surfing around, probably my first time ever reading this particular forum.

 

Thanks for the help. I fully plan on posting all the mods and pics when the project reaches the ashphalt and tire melting stage. Have a Merry Christmas.

Scott.

P.S. There is an awsome group in Yahoo dealing with EEC.

http://autos.groups.yahoo.com/group/EECTuner/

These peps are really into the innerworkings and modification of the EEC system.

 

Hi Ken. Looked at the motorhaven site and have a Q. Noticed you have service manuals for my year of truck (72 F250) but no assembly manual. Can you guys scare me up an assembly manual for a 72 F-250 Sport Custom.

Thanks, Scott

 

Unfortunately I don't have a later year assembly manual. The earlier 70 assembly manual is going to be pretty darn close, with probably 95% of it being the same for 72.

 

Thanks Ken. I will order them soon.