cfi to multiport

[red86v6]

I have an 86 3.8 with cfi and dont think I can pass ca smog this year. Where can I find info on how to swap in a 98 or newer 3.8 w/ 4sped auto trans with associated wiring. Want more power, fuel economy and to pass smog. A 70 w/ 302 is my hot rod, I just want a little more go with a bunch more econ. My 3.8 only gets about 16mpg. Any help would be greatly apreciated.

[rbohm]

ok to start, you are going to need the wiring harness for the port efi system, along with all the attendant bits of kit, like sensors, computer, distributor, intake, etc. you have options though for donor cars. the 89-97 thunderbird used the 3.8 with port injection, as did the 94 up mustangs. the ford F150 used the 4.2 V6 starting in 97 i think, and they ran through the 2012(?) model year roughly. and then there is always the megasquirt system. so here is my advice;

find a 2002 or later F150 with the 4.2 V6 with two wheel drive. it will bolt in place of the 3.8 as they are virtually identical, though i would dump the truck upper intake and find a windstar upper intake as it will be an easier fit under the mustang hood, though you will likely have to relocate the IAC motor but that is not a big deal. buy yhe whole vehicle as you will need lots of stuff from the truck to make the swap work.

get a wiring diagram for the truck and your mustang, as there are going to be times when you will need to consult them to get the wiring right.

the nice thing about the 4.2 swap is that you gain a fair amount of power, and thus you will pick up fuel economy.

this link is for the mn12 thunderbird, but you can use it to also do the 4.2 swap into many different vehicles;

http://forums.tccoa.com/showthread.php?t=6680

one more thing, treat this swap as a carb to efi conversion.

[Travis T]

The 99-04 V6 Mustangs have better parts than the 94-98 if you can score yourself a Mustang parts car.

[red86v6]

rbohm,
The tccoa thread is very informative, the 4.2 truck motor is something that I had not considered, I'll add that to my list of possibilities for the swap if my 86 fails smog. Thanks much for the info. (If a swap is necessary I will get a donner vehicle)

[Marz]

Red: If you're in California it is not legal to swap a truck motor into a non-truck.

That being said. As of early Feb of this year my LTD LX received it's BAR sticker saying that it was an approved engine swap. My LTD LX went from being a 85 CFI 5.0L V8 car to an 89 Mustang 5.0L V8 car. It's very simple. Just swap every emissions part along with the engine from the donor car. They like it even more if you have the VIN of the donor car.

[red86v6]

marz,
Yes I'm in Ca. (High dessert) Guess that kills the truck motor swap. Thanks for the heads up.
Probably the best route for me will be buying a doner car (98 and up) and dropping in the engine, trans, ecu, wiring ect. in my 86. 5 lug conversion /w brake upgrade will be nice too.
I've seen some full interior swaps that look great but don't know how difficult that would be.
anyway monday is smog day and if it fails I'll inop. the 86 and start from there.
Been talking to MCE engines guru Marvin McAfee and he has given me some ideas on how to pass smog so we will see what happens. (The guy builds fantastic engines only wish I wasn't a retiree and could afford one.) He is in the LA area check him out on the web.

[red86v6]

RATS!!! shouldn't have used E3 plugs. Marvin warned me but I listened to the wall street BS and failed miserably. 4X co & HC. Only 3 days to correct it. #2&3 plugs are carbon coated, but the # 2 &3 plug wires were parallel for enough distance to cross fire by induction so I corrected that rechecked timing, reset fuel pressure to 39 psi,cleaned EGR valve, replaced pcv valve, replacing # 2&3 plugs.(1,4,5, & 6 are new and are clean) Also on the list is to check valve train geometry, might need some shims due to former head work. Will recheck thursday, and hope not to have to do all 3 cats.

[rbohm]

sounds like you are blaming the plugs for other issues.

[red86v6]

Rbohm,
True on the plugs but they are pre-gapped at 60 thousandths a little over the 56 max for ca. plug gap. All the reviews are good for the E3 plugs and perhaps I over reacted a bit by pulling them. O2 sensor was carbon coated so I replaced it on the 1 2 3 engine side. Car runs great now so will do an emissions pre-check in the am.

[Black97Tbird]

From memory, here's a few things about 3.8's in MN12s/Foxes...

If your donor is a 89-93 3.8L Thunderbird/Cougar, it's EEC-IV/OBD-I. These were equipped with AOD transmissions.
94-5 Thunderbird/Cougars were the same engine, but with the 4R70W (electronically controlled) transmission.
94-5 3.8L Mustangs are similar, but may also appear with 5 speed transmissions in addition to their AODE (electronic, but using the AOD ratios/gearset).
96-7 Thunderbirds/Cougars would have EEC-V/OBD-II, and 4R70W transmissions.
Again, 96-8 Mustangs are similar, but may have a 5 speed.
99+ mustangs are split-port, which is a nice boost in power, but it's more work.
IMO, if I were doing this swap in CA, I'd stick with an OBD-I car if I could, it's just less wiring and work to set up. If you need the power, definitely go 99-04 Mustang, and get the EEC and wiring from a 5 speed car if you want to use an AOD/C4/5 speed instead of the 4R70W. A donor car might not be a bad option.

Tom

[red86v6]

Setting the fuel pressure to 39 lbs sent the CO & HC counts off the charts! Beyond the gross polluter limits. #2&3 have a bit of carbon/oil on them light and fluffy stuff. Tried to check the umbrella seals but the second flat coil spring on the inside blocks my view. From what I could see it looks like the seals are in the proper position. Maybe worn guides I don't know?!! Put in a bottle of cat cleaner and dropped the fuel pressure which puts me back to square one.
A doner car w/ auto ( wife likes auto) is looking better all the time. OBD-2 makes trouble shooting easier, wiring more complicated. Will do another recheck Friday and go from there.
I truly thank all you guys for your inputs and experience.

[rbohm]

it sounds like you have a bad injector or two. perhaps have them tested?

[plstktnkr2]

If you use the truck bottom and the car top- end would they notice? just askin'
Rick

marz,
Yes I'm in Ca. (High dessert) Guess that kills the truck motor swap. Thanks for the heads up.
Probably the best route for me will be buying a doner car (98 and up) and dropping in the engine, trans, ecu, wiring ect. in my 86. 5 lug conversion /w brake upgrade will be nice too.
I've seen some full interior swaps that look great but don't know how difficult that would be.
anyway monday is smog day and if it fails I'll inop. the 86 and start from there.
Been talking to MCE engines guru Marvin McAfee and he has given me some ideas on how to pass smog so we will see what happens. (The guy builds fantastic engines only wish I wasn't a retiree and could afford one.) He is in the LA area check him out on the web.

[rbohm]

If you use the truck bottom and the car top- end would they notice? just askin'
Rick

that depends. if he used the rotating assembly from the 4.2 in his 3.8 block, no one will notice. if he uses the truck block however, they will.

[plstktnkr2]

that depends. if he used the rotating assembly from the 4.2 in his 3.8 block, no one will notice. if he uses the truck block however, they will.

Sounds like a plan then...
Rick

[red86v6]

Got a star tester and found out that the o2 sensor readings are low fault 41 , evap or PFE circuit fault 31, thermactor system fault 44, and thermactor air diverter solenoid fault 94 came up. The O2 sensor readings may explain the ultra rich mixture problem. My manual doesn't show locations of much of anything so it looks like I'll have to find an original ford shop manual. tracing out lines manually is very time consuming. My next step is to check to see if my O2 wires are actually connected to the computer and check out the 5 solenoids under the radiator overflow container. The ecu itself doesn't show a failure code so I hope it's OK. A lot of the wiring is heat cracked so that may be the cause of some problems too. Good thing I have lots of time to work on this.

[red86v6]

Ordered an original Ford electrical and vacuum book. Hope that it will shed some light on what computer is supposed to be in this car One book says EEC-III another says EEC-IV. Ca emissions is Fun

[red86v6]

Swapped out the injectors, New O2 senors read lean at idle, but nearly max out at 1200 RPMs, found out that my replacement computer is the wrong one so I will order the right one when I get the Ford manual and confirm that it is indeed a wrong part number computer. Ca cars use the EEC-IV but there 3 different part numbers depending on vin# and Ford doesn't keep those old records.

[red86v6]

Changed computers and only have faults 94 and 44 and an air diverter solenoid should cure it.

[Marz]

Code 44 and 94: remove the air injection tube that goes to the rear of the cylinder heads and clean it out. Also clean out the injection passages in the heads. Also, strange... but replacing the smog pump fixed my issue.....

[JACook]

The '86 TAB/TAD solenoids are known to be problematic. Make sure you do not have -any- air to the
cylinder heads when the engine is trying to run in closed loop. The extra air will fool the O2 sensors
into commanding the system to go rich. The air should only be upstream when the engine is cold,
and at WOT (when it's bypassed anyway).

Also be aware that the later MAP/Baro sensors are not the same calibration as those used on '86s.
My '85 CFI car had the wrong sensor, and I had the same issues with a very rich condition whenever
I put the fuel pressure right.

[red86v6]

I bench checked the solenoids OK will clean out the air injection system to the heads. Used a vacuum pump to check function of the air injection system and had flow. O2 sensors are reading about .4vdc at idle and up to 1200 which from my understanding is about right. Will weld in the new cat and test monday. Fuel pressure back to 34 May have to get a junkyard map sensor if all else fails.

[red86v6]

Marz
Checked the back flow valve from the smog pump to the heads and found it to be defective so have it on order plus I decided to replace the one for the cat while I was at it. There is a lot of reverse exhaust gas flow coming out if the valve so the head passages are clear. How do I tell if the smog pump is putting out enough flow? It has flow but I don't know if it is adequate. With the new cat the & all the new parts, the exhaust smells clean but that really doesn't men it will pass California emissions. You guys have been a great help. Thanks much..

[red86v6]

failed again

[Marz]

Red. My Smog pump flowed as well... but looks like it didn't flow enough. since replacing the Pump there has been no codes.

post a pic of the smog results. How did it fail?