99 V6 to MK8 swap no spark

[1stanger1]

here is what i have

i have a 99 mustang that had a V6 i replaced it with a 93 lincoln MK8 4.6 dohc
(got it for free 38,000 miles and bad bags) the mark8 ran perfect but now i have it in my mustang got mostly everything hooked up
i am using a 96 cobra upper and lower intake and imrc's with butterflies deleted
stock mark8 engine harness (i will eventually use a cobra harness)
a 96 cobra PCM and a 96 cobra PCM harness
now the 93 mark used the EDIS8 module while the 96 cobra didnt
so i wired the motor up like it was a 96 cobra ran everything through the PCM but didnt use the EDIS of course

and i have power at my CKP and i have power at my coils....the middle wire i think its red/light grn
i have the yellow wire at the pcm pin 55 at constant power and pin i think 72 and 91 i think those are the right numbers are 12v in run and start
when i turn the key on i have power at the coil(red/lghtgrn) but the problem is is when i have poser at that wire the other 4 wires (between the 2 coils)
there is 12v there too is this right??

my engine turns over by the key i tapped into the wht/pk wire that is only hot in start and it works good that way
i dont know if i am getting fuel the other wires that run through the firewall for the PCM harness are not hooke up because between 96 and 99 the plugs are different they just run the rear lights fuel pump and dash junk.....
anyone know if its my PATS ??

tell me what i am doin wrong i have no spark

 

[Mike97gt]

Pats disables fuel so I don't think thats it..


BTW how did you get the 93 mark harness to work with a 96 cobra PCM? Did you repin everthing properly?


If I was attempting this I would have gotten the harness from any 96-97 mustang v8 since that is a much easier repin

I will try to take a look at the wiring diagrams tommorow and maybe we can figure something out

 

[1stanger1]

i really didnt have to repin anything like i said i am using a cobra pcm harness and a cobra pcm and according to all the diagrams i have been staring at all my wires in the big black plug in the passenger side rear corner of the engine bay are correct......i mean i think there was a few i had to move around i forget.....
but what i am concerned about is is when i turn my key on i get power to my coils the rd/grn wire but why do the other 2 wires on each coil show 12v? is that right and if so why am i not getting a signal to tell it to fire?
just replaced the cranksensor and tested the wires to see if there was resistance there and there is everything seems to be working...i dunno whats goin on

 

[billfisher]

the two harnesses arent compatible. eec-iv and eec-v arent the same you'll need to get a 96 harness. and it will start right up.

 

[billfisher]

the power to the coils will be there, but a ground disconnect done by the pcm is what fires them. if that wire isnt going to the right pin it will never fire.

 

[Mike97gt]

I thought you said you used the marks engine harness..

 

[billfisher]

if he did it wont work.

 

[1stanger1]

ok bill what wire is wrong what is being hooked up?......according to the pinouts from a 96 cobra and a 93 MK8 i have everything hooked up as it should but heres is what i am changing today......

i picked up a computer from a 96 MK8 which is a 104 pin and an EDIS8 from the same car which theoretically should make the car start just like its still a MK8 but being that i wired the starter up the way i did .......i can start it by the key and everything else should work too............i.e fuel pump, injectors and all that jazz being that they worked before all this......and i dont have 3/4s of the wires inside hooked up either the ones that go to the gauges and stuff that is

 

[1stanger1]

32V has no spark

heres what i am looking at......
99 mustang removed V6 and auto trans

motor is a 93 MK8 ,99 gt pcm harness(modified)
96 MK8 pcm
problem: no fire
fuel pump works, injectors fire but no spark...

according to all my diagrams there are 3 wires at each coil the one in the middle (rd/grn) has 12v in run and start........(which i do....) thing is when i turn the key on i have 12v at the other 4 wires on the coils...dont think its supposed to be that way
i dont really need any more diagrams just a little insight to this

everything is wired perfectly no wire is out of place....a few not wired in but who needs O2 sensors...

 

[squeak93]

Did you flash the pcm or just modify the harness? I don't think a gt puter will run that motor w/o a flash.

 

[billfisher]

llok man, you need to listen to us. you know how many folks do this very thing and NEVER get it running? all the time man. all the time. reposting because you dont get the answers u want from a ford tech and others isnt goin to fix it. hey it aint my business.

but the motor in my car now i paid 165.00 from a guy like you who swapped it and couldnt get it to run. i built it and put it in, and mine ran the first hit of fuel.

 

[fast97gt]

what about your crank position sensor? check it and let us know, yes if its bad itll not send the information to the computer to signal coils to ignite the fuel

 

[blubullett]

Why don't you use the 99 gt harness with the 99gt computer and coil packs and so on. Then the only thing you should have to change is possibly lengthening a few plugs or whatnot.

I just read your other post and you keep saying you have everyhting hooked up correctly. WELL OBVIOUSLY YOU DON'T. And when someone asks you what wires you mover around and you can't even remember if you moved any then maybe you need to start over.

It seems like you are using a hodgepodge of parts and trying to make it work. At least get a computer and wiring harness from the same car. Perferably a mustang. Stop picking up all these harnesses and computers from different cars and hoping it will work. You need a Mustang harness for it to work in a Mustang

svttech76 knows his chit. He IS a svt tech. If you need help with wiring he is the one you need to listen to. Also billfisher's car actually works.... so maybe you should try listening to him too.

Also try hooking everything up. Your car doesn't work and you have all these wires just laying around.

Ill give you $165 for it when you give up.

 

[1stanger1]

first of all i dont give up..........
and as far as gt harness and gt pcm tried that too......

on the engine there is nothing that is not hooked up.....

the only wires that i didnt hook up when i was wiring the mark pcm connecter was anything for the trans and anything for the o2 sensors....

i stared at a diagram for 3 hrs as i was changing the pcm connector

the connector i used was the 96 mk8 and adapted it to a gt PCM hrness
the reason i used the GT harness was that it had more wires than my original V6 harness....and i needed more wires because of the coils and other stuff that the V8 has that my V6 didnt.

Now that i recheck my stuff i see that i have no fuel pump power ....which i thought i did

now i did check to see about signal by using a test light on one of the 3 wires to the one coil.. i touch the test light to the one wire and the other end to a ground and the light came on then cranked the motor it dimmed slightly and pulsed just like a dome light would so i guess i am not getting a signal from somewhere

now when i changed it from an auto to a stick and put the peddles in i didnt hook up the wires for the clutch.....meaning the wires that only let it crank when the peddle is pushed and

the red/grn wire for the power to the coils had no power b4 so i ran it in under the dash on the drivers side to the igniton switch plug

and whats with that damn theft light flashing like hell oh and when i hook the pcm up and turn the key it my mileage shows ------------ unlike when i hooked everything up b4 with the gt pcm it showed the vehicles mileage

so hey there Mr. bill nice to see yours runs but it seems your like everyone else....they say they got theirs to run but no one wants to share information.... or they start a thread and have problems and then fix it and never come back to it to say they resolved it and what the problem was....not trying to be a dick or anything but everyone does it

so whats your parts list any ideas if yours runs i'll do it your way.....

 

[BlownFiveLiter]

Two threads on same topic merged for easier time troubleshooting the issue.

 

[billfisher]

hey man im trying to help.


i used a known quantity. this pcm has run the stock motor, a 5.4 3v and now a massive HP mid boost 4v.
nothing to chance. ill back up a second.

do you have a obdII scanner. if you do. hook it up and turn on the key. if it communicates your pcm to harness is hot. if it doesnt communicate. you have either no poewr to the pcm or wiring is goofed up.


going froma v6 to a v8 is a mess at best.

im going to give u the same advice i would do myself.

ditch everything that isnt factory matched. same year everything pcm.all harnesses froma donor. period.

then try starting it.

 

[1stanger1]

okey dokey bill i got the 96 cobra pcm harness and the 96 cobra pcm hooked to it......there is only one problem the other smallerplugs on the 96 wont plug into the on the 99 car inside the kick panel? do you have a chassis diagram or do you know what color i should hook to what?

or should i just get rid of all these damn harnesses and pcms and get a
99 cobra pcm and harness change the engine harness as well

so you did your mk8 swap into what year mustang and what parts did you use?

just curious

and no i dont have a scan tool

 

[blubullett]

I don't want to confuse you and I really have no idea to help you but in one of the last few MM&FF mags they were swaping a 4v into a bullitt and they didn't have any spark because they didn't hook up some harness for the auto trans and the coil wires were routed through it. If you have an old auto harness in your car cause its an auto it might be something to look into....

 

[1stanger1]

well if there was (in mine) there isnt anymore i can garuntee that....i took it upon myself to run a bunch of new wires and those were a few of the ones i added to the harness but i think i got everything almost taken care of...

i switched back to my 99 gt harness modified slightly and cut off the pcm connector and replaced it with that of the 96 mark pcm connector.....dont know why i did it that way i should have just repined it but oh well at least i know its right... i am gonna attach 2 pics of 2 pinouts to show what wires i didnt hook up .....reasons: no plce to hook them and no need for them

like i said trans crap and o2 sensors

 

[1stanger1]

v6 to mk 8 no spark *UPDATE*

well finally i have spark.....turns out i had the crank sensor hooked up backwards...duhhhhhhhhhh
my injectors are firing i hooked the multi meter to them and the voltage goes up then down the back up then down so i know they are working....

BUT

no i have no fuel.......

at the harness wher it goes down through the trunk there is a small red wire and a small yellow wire which are for the gauge
then there is the weird wires that i dont know what they are for and cant find them in any diagram that i have

they are: blk/orange, brown/pink, red/black, and brown/white

the red/black is supposed to be a ground and the brown and pink is supposed to be a hot wire the others i have no idea

whats funny is the red/black wire has power going to it which i know is wrong dont know why or where it goes or comes from

then at my fuel pump driver module the LB/orange wire pulses with the test light even with the key off i dont know why this is either

anyone know what i should do? Bill?