1989 2.3 MAF conversion installed - doesn't work!
I just installed a MAF system from a 1991 2.3L Mustang in my 1989 2.3L Mustang automatic today and it doesn't work at all. (non-turbo)
I removed the MAP sensor hose and plugged it off. Then started the engine and it was burbling. We put the hose back in the MAP sensor with the MAF plugged in and it was running perfect again. Unplugging the MAF does nothing to change the way the engine runs.
Here is the wiring info:
A to pin 37
B to pin 60
C to pin 9
D to pin 50
MAF is part number F0VF-12b579-A2C
The ECU is a 8CB - E8TF-12A650-CT3A EEC-IV
The ECU and MAF are from good running cars and we tried the same 8CB ecu that came out of this car but still nothing. The wiring is correctly installed.
So where are we going wrong? Do we need an ECU from a 1991 2.3L Mustang? The ignition system is different on the 1991 2.3L - 8 spark plugs.
I posted this in another thread but it wasn't the tech section.
Any help would be appreciated!
do you still have the vaccuum line running from the intake to the BPS? that can cause problems - when using a MAF vice MAD the BPS vaccuum should be capped at the intake and left open at the sensor. That was my problem on my conversion.
BPS? or MAP sensor? I capped the MAP off at the manifold.
Wouldn't changing the whole wiring system involve the DIS module and coil packs? Thats not really what I want to do...in fact from what we've done to the car that would be a step backwards.
If I can take the engine computers apart, find the MAF section from the 91-93 ecu I can adapt that to the Pre-90 8CB ecu. My dad can build a circuit board for it and place it inline with the MAF and ECU if we knew which section of the ECU it is.
We have a couple 2.3L Mustangs we're working on, both converted to MAF and both have MAF/MAP problems.
One is a 1990 Mustang 2.3L 5 speed Turbo...it won't right at all. In fact, when we asked what might be the problem in this forum a few months ago we tried everything that people told us to do and everything we did just made it worse. I hooked up a laptop to a code scanner mounted to the car and it had no codes, the problem it had was it would run but sputter at low RPMs.
Then after we tried a few suggestions that people gave us we burned the O2 sensor, MAP, MAF, VAM, 2-TFIs, the brown top injectors stuck open, the coil and 3 spark plugs melted the electrodes off while the 4th spark plug's electrode was ok.
We've had over 30 1985-93 Mustangs, all but these two 2.3L cars had 5.0L V8 cars. All of the 5.0L cars ran and drove great, everything we did to them just made them better cars...so why would 2.3L cars give us so much trouble?
The DIS ignition system is very similar in wiring to the old TFI/Distributor setup.
You can't take the ECU apart and remove and swap sections. It just doesn't work that way. Do some research and you'll see.
A 2.3 is not a 5.0. That's it in a nutshell. Because it works on one, doesn't mean it will work on the other. The best thing to do would be to stop looking at the problem from a 5.0 perspective and find out what the 2.3's do differently.
b_chandlerThe DIS ignition system is very similar in wiring to the old TFI/Distributor setup.
You can't take the ECU apart and remove and swap sections. It just doesn't work that way. Do some research and you'll see.
A 2.3 is not a 5.0. That's it in a nutshell. Because it works on one, doesn't mean it will work on the other. The best thing to do would be to stop looking at the problem from a 5.0 perspective and find out what the 2.3's do differently.
The DIS system would pretty much mean that we need to remove an ignition system which we modified and which works. We don't fix what isn't broken but we do modify things to operate efficiently and for more power.
The ECU is the EEC-IV unit which can be altered internally in the way I explained. You say do research on it but apparently you don't know that every internal part of the EEC-IV can be expanded inline with the wiring harness because its what we did with an Econoline van 5.8 transplant to a 1993 Mustang. We dissected the ECU to inline mount the processors onto a heatsink with a PC computer 12VDC fan blowing cold air through them.
We aren't looking at a 4 cylinder 2.3 engine in a 5.0 V8 perspective.
What I said was "We've had over 30 1985-93 Mustangs, all but these two 2.3L cars had 5.0L V8 cars. All of the 5.0L cars ran and drove great, everything we did to them just made them better cars...so why would 2.3L cars give us so much trouble? "
I apparently stand corrected. I can honestly say I've never hacked apart an EEC-IV ECU. Primarily because I never saw the need to.
There's a post here I made a while back that included a PDF drawing that shows how to run DIS with an old TFI harness. I'm sure that with your knowledge, you can reverse engineer that to run TFI on a DIS ecu.
When I try to put together what you're doing, I think of the programming in the speed density ECU that interprets the frequency change in the BAP/MAP sensor and compares that to a preset table of values that correspond with preset fuel and ignition timing tables. The MAF ecu on the other hand, looks at a 5V swing coming from the MAF sensor and interprets that against a set of values that correspond to fuel and spark values. The numbers, math, and function are entirely different. It's not like the main programs are identical and there's just a different group of interpreters. I'd really like to see the stuff you've done. It's certainly got me curious.
Perhaps I'm wrong, but the homework I've done suggests otherwise.
I know that the code in most Ford computers can be modified with great success. The turbo guys have been doing it forever it seems. Personally I think that's the way to go rather than tearing the computer down to component level and reinventing a wheel that just needs tweaked.
You're the first person I've encountered that's ever gone after an EEC-IV box with a soldering iron instead of a laptop or an EEPROM burner. Not saying that's wrong, it's just further outside of the proverbial box than I've ever seen.
One other question. You said after following advice found here, you burned up the MAF, MAP, and VAM among other sensors mentioned. Did you have all three on the car at once?
I don't know if they're exactly the same or not, but it's a fairly safe bet. I ran the pins you tied to against a pinout chart I have for a 1987 speed density 2.3 ECU (DA1)
You've got A tied to vehicle power which should be the 12V you need.
B is tied to ground
C is on Pin 9 which is labled as DATA I have no idea if that's in or out. I don't think that's where the MAF sig ret should be.
D is on Pin 50 which according to my chart, goes nowhere. That's the MAF signal.
Does this help any?
Interestingly enough, there are two terminals labled MAF and MAF return but they are listed for California cars only. They are pins 14 and 15 respectively. Might be worth a look.
I just tried the maf conversion on my 1988 2.3l mooootang. The correct pins for the maf are
A to pin 37
B to pin 60
C to pin 15
D to pin 14
You do need a Computer from a MAF car.
Info found via. "Alldata" online and autozone online repair manual. I ran into a problem with a lean crappy idle and lean at WOT. reverted to speed density for the time being, till its figured out.
(used stock maf and injectors, 19# injectors and two different 5.0l 19# mafs)
You NEED the computer that is supposed to run the the fuel injeciton system on your car. It sounds like youre trying to use the old speed density computer on the MAF system? If so that will not work. You need a MAF computer. I did this the MAF conversion on my 77 Bronco that has an 86 lincoln 5.0 in it and I can tell you that to try and get fancy with electronics is way more trouble than its worth. Get what works, and is SUPPOSED to work. A computer doesnt cost that much from junkers/ebay/wherever. It also sounded like earlier in this thread you were confused about the MAP and BPS sensors? They are the same thing, depending how you hook them up with vacuum, they measure different things and are thus different sensors but also the same sensor.
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79 2.3 turbo coupe
80 notchback 5.0 swap in progress
93 thunderbird
77 Bronco with 5.0 EFI
I used a grannettelli conv kit. it has a high rough idle for 15 sec, smoothes out, but wants to allmost die off idle . poor mpg and check eng light stays on. codes#52,[psi switch open] #85 [canister purge circut fail]and #95[fuel pumpsecondary circut fail]. I downloaded both cars wiring diagrams and they have a few computer pin differences.the psi switch is #29 on my car and #49 on maf car.thats an easy fix but the other codes have got me stumped. my car has no canister purge solinoid.my fuel pump is wired different, maf goes through a integrated relay. my fp relay became louder after swap...?swapped it out till i figure it out. my car is a 1989 must lx 5 spd conv., donor car was 1990 must lx 5 spd hard top. any help ?
1989 2.3 MAF conversion installed - doesn't work! 
