anyone reprogram an EEC-4 OBD-1

[olddog]

Byron,

Do you know what GM engine and year would be the same as the MAF meter in my MassFlow system?

I'm considering just tossing another one on it and seeing what happens. Or is this silly to try because its calibration curve would have to be figured out as well?

[ByronRACE]

I'm pretty confident the guys are using a GM/Delphi maf because I've seen it before in datasheets, on the web, or in boneyards...but I can't tell you what exactly they are using. My guess is they didn't have a special calibration made just for their relatively low volume purposes..that would be cost prohibitive. But what exactly they are using and how to obtain one is beyond the scope of my knowledge, sorry.

[olddog]

I got the impression from talking to MassFlow that my EEC is still bone stock the way Ford made it. The newer stuff MassFlow sells is chipped and they put a tune in it based on your engine. They will redo mine that way for about $250 or so, if I send them my MAF, and EEC. I'm sure it would improve things, but I just don't see it doing as well as actually measuring the exhaust on the actual running engine.

[ByronRACE]

You're right, there's nothing better than doing your AFR tuning on the engine in question.

However, the difference between what you are running now (a calibration designed for a 5.0L Mustang with a 137 firing sequence, 301.08 cubic inch displacement, 19lb/hr injectors, smog legality, etc...etc...) and the *right* calibration for the parts that the EFI system is actually connected to is going to be night and day....even before performing the fuel trim operation on the engine in question. You can do this baseline tuning stuff yourself with the tweecer, then you'd have the ability to take it further if you so chose. If you have massflow do the baseline stuff, that's probably where it ends because you don't have their tuning software/system. The only thing stopping you from doing the baseline calibration stuff yourself is knowledge of the massflow curve in Volts vs KG/Hr. If they'll give you that, you're home free and you could have this put together in an afternoon.

BTW, I ran a google image search and ran into this...which looks familiar I hope. There's an applications list on the page that suggests this is a GM type maf...so whatever you have is probably a GM type maf. Probably not this one though; I'd suspect they'd use something from a performance vehicle so it has enough measurement range (Corvette, Camaro). Again, just a guess.

http://www.cheaptruckparts.com/produ...ucts_id/27187/

http://www.corvetteguys.com/mass-air-flow-sensors.html

[ByronRACE]

What is the firing sequence on the engine you're running. If it's 154, I have some input why you're having problems.

[olddog]

Originally Posted by ByronRACE

What is the firing sequence on the engine you're running. If it's 154, I have some input why you're having problems.

No. Mine is the 137.... So I think my cam is the correct firing order for a stock 5.0 EEC.

[olddog]

I'm starting to turn pink. It's past my bed time so I'm going to go to bed before I finish turning into a pumpkin. Catch you later.

PS that sounded rude. I didn't mean it to. I have a car show tomorrow and a full week end of out of state relatives. I cannot wait to dig into some of the links you gave. Then I will have even more questions. It may take a few days to get back to this.

Thanks

[ByronRACE]

If the guys at Massflow are running a stock PCM, then we already know what the resulting MAF curve being fed to the PCM is.

It's the factory ford 19lb/hr curve scaled to whatever the change in injector size is...exactly the same thing they do on 5.0L mustangs. The only detail in this case is that this "scaling trick" is being done in a frequency to voltage converter box. In a Ford MAF they calibrate the analog electronics to scale the voltage. The massflow guys do something else. They probably use a microcontroller, calculate the frequency of the GM MAF output, then use an internal lookup table to look up what the output voltage should be, and produce it using a digital to analog converter. This allows them to put anything they want in the lookup table and translate any GM input curve to any Ford analog output curve; and scale it for any size injector. That's a lot of work, but it lets them use off the shelf stuff that's easier to cram into an air filter than the Ford design. This lookup table would also allow them to avoid hitting the .4V minimum voltage that flags a check engine light when you use the "scaling trick" on big injector engines. Once you get beyond about double the factory injector size, you start hitting that .4V in the idle range and the PCM goes into limp mode. They probably flatline the output above .4V to avoid this...so they can make 40+lb/hr injector calibrations run on factory PCMs.

Anyway, if you're running a factory Ford pcm (look at the prom like I suggested for signs of tampering), we know what curve is being fed to the PCM. One less thing you have to ask for.

Byron

[Mac VABCH]

Olddog,

Byron is correct that you have a factor unchipped PCM. MassFlo initially sold there system in stock form now he uses a piggy back chip to tune for displacement and injector size. I have not been able to tune the PCM to the new meter after massflo sent me the flow sheet as I have been out of the country for 3 months. I will say that when I first received the new meter withot a flow sheet we couldn't get the tune right as it was very rich. When I sent the meter to Chris at MasFlo he said that there must have been oil contamination to the mete/intake which he suggested was from to much oil on the filter. This was not the case as the filter hadn't been reoiled in a quite awhile. Where the oil contamination came from was the PCV. I have since deleted the PCV and just put a filter on the valve cover. I will be returning to the states next month and will get the tune right then. I still think that your injectors are 1 size to big as I have had the motor running great and only making 340 WHP. This was with a 12yr friend that does this for a living tuning it over and over again to get the most out of the engine. I don't put to much faith in pc dyno numbers. JMHO. I'm not sure if I gave you the email or not to my tuner but he uses Diablo chip and has a tune for my car on file when it ran great. brenth@dtpracing.com
He can give you his opinion as to which way to go either a Tweeker or Diablo or have MassFlo do it. I will say that if you go with MassFlo it will be a guess, if you go with Tweeker you will have to learn how to tune it and spend expensive time on the dyno or data log on the street. Brent should still have a good tune that will be very close for you setup as we have very similar engine but not perfect. Mac

[DonC]

Olddog:
You may very well have a chip in the J3 port of the A9L supplied by Mass-Flo to adjust for whatever combinations are in the engine.
According to Tweecer, if you order the Tweecer unit and send them the J3 chip they can read it for you and create a .bin file to load into the Tweecer before you start. That way the Tweecer is providing the same information to the A9L as the J3 chip installed now. From that point you have a functioning unit and can tune from there.
For a small fee they can also read and create the .bin file from the chip without purchasing the Tweecer.
I have a Mass-Flo on my 428FE and, while the system is running well I'd still like to refine it just a bit. I'm thinking seriously of going the Tweecer R/T route this winter when the car is up for it's annual maintenance/modification/cleaning all the accumulated gluck off of it session. Like you I'm a relative novice to the EFI tuning world so it should have some "interesting" periods.
DonC

[olddog]

Ok I down loaded the .pdf file for the Tweecer manual and read it a couple times. It leads me to believe that you can down load all the tables from an EEC IV, but stopped short of stating that you can transfer this file into the Tweecer as one of the 4 selectable tunes, allowing you to start with a tune identical to the factory settings. If you can do that, you could start identical to where you are at. Is this doable?

I'm thinking the first thing I should do, is correct all the modification that were done to my engine. Put in the right CID, the enjector size, and mass flow meter size.

From my understanding they likely set my MAF up with a range larger than my engine needs. Since the factory used 19 lb/hr and I have 36 lb/hr injectors and I'm guessing the factory used about a 650 cfm meter, the math comes out to 36/19 * 650 = 1230 cfm. I think I was either told by MassFlow or read it in the literature that it is 1200 cfm. That is likely too big for 347 cid. I'd think 700 cfm would be enough. Is only using a little over 1/2 the range of my MAF going to hurt the resolution enough to matter?

[olddog]

To get the O2 sensors close enough to the engine, they had to be located into a single header tube. The collector is 1/3 the way down the pipes that you can see on the car. Also my pipes are jet hot coated. I don't like the idea of welding bungs into my side pipes. Is there a way to just slide the wide band O2 sensor up the side pipe from the outlet?

Also I have read some comments that some wide band O2 update rate is so slow compared to how fast the rpm comes up that it gives you numbers but you don't actually know what the rpms were, making it hard to correct your tables. Is wide band O2 the best technology to use? Are some O2 much better than others?

[olddog]

For anyone else interested in the tweecer here are a couple video links.

http://v8tvshow.com/content/view/216/28/

http://v8tvshow.com/content/view/217/28/