Skip to main content ↑ ↓
Topic: EVTM help request (Read 1328 times) previous topic - next topic

EVTM help request

EVTM 1987 bird/coug Page 60 showing the last section of the EEC pin outs.... the 88evtm may be the same.

I have been working on a resto and finally made it past start up day with my chip and a basic tune to get it running.

i wanted to make time to verify voltage at my TPS green wire KOEO and set up to do that.

i grab the connector and notice the chassis side harness (from the Computer), the color code of the wiring was not matching my blk/org/grn color coding of the tps.  i dd a double take and started to worry.


I was forced to extract the computer and go to the two pins i can account for and verify continuity which were 47 and 26.
for the designated blk/wht, i toned out and found no issue other than color..

so... for my tps it goes like this

wht/rd  ends up becoming my Blk/wht wire somewhere

Gray/wht ends up becoming Dk G / Lt G at pin 47 of the eec
Brn / wht ends up  becoming Org/wht at pin 26 of the eec.


Has anyone noticed this issue around the EGR/TPS/Map sensor circuit?

This EEC harness came from an 87 5.0L cougar out of a junk yard up in pa that replaced my former CFI 3.8L EEC harness.
I had no reason to question it other than inspect it as best as possible before installing.  I did not notice this TPS wire color issue then.

this EEC harness has nothing to do with the fuse box harness grafting work i did to upgrade it as well to a 5.0L application.


I really need opinions.

I am testing for the presence of 5v and less than a volt on the TPS center tap in in a few.

the first pic is the MAP sensor connector.

the second pic is the EGR (left ) and TPS (right) connectors.

I think two things...................
this was an assembly line screw up that was "made to work"
or
Ford had a short fall on certain color wires during that day and used what they had.
at the end of the day,, if it has continuity to where it belongs,, it will work, i just need to dospoogeent it in my son's EVTM.


scott
304 772 3411

EVTM help request

Reply #1 –
I'd open the harness up and look for evidence of a pigtail replacement with a similar connector off of a different Ford vehicle.  As a recovering dealer tech, I will tell you that dealer techs horde harnesses for the purpose of scavenging them later.  You may have had a similar repair earlier in the vehicle/donor vehicle's history.  That is, I suppose, the problem with 30+ year old cars.  They've had lots of hands up their skirt.

EVTM help request

Reply #2 –
The 93 T-Bird EVTM shows the wire colors you ran into.
Foe is right, someone must have spliced on a connector from a newer car.

EVTM help request

Reply #4 –
Quote from: jcassity;466658
EVTM 1987 bird/coug Page 60 showing the last section of the EEC pin outs.... the 88evtm may be the same.

I have been working on a resto and finally made it past start up day with my chip and a basic tune to get it running.

i wanted to make time to verify voltage at my TPS green wire KOEO and set up to do that.

i grab the connector and notice the chassis side harness (from the Computer), the color code of the wiring was not matching my blk/org/grn color coding of the tps.  i dd a double take and started to worry.


I was forced to extract the computer and go to the two pins i can account for and verify continuity which were 47 and 26.
for the designated blk/wht, i toned out and found no issue other than color..

so... for my tps it goes like this

wht/rd  ends up becoming my Blk/wht wire somewhere

Gray/wht ends up becoming Dk G / Lt G at pin 47 of the eec
Brn / wht ends up  becoming Org/wht at pin 26 of the eec.


Has anyone noticed this issue around the EGR/TPS/Map sensor circuit?

This EEC harness came from an 87 5.0L cougar out of a junk yard up in pa that replaced my former CFI 3.8L EEC harness.
I had no reason to question it other than inspect it as best as possible before installing.  I did not notice this TPS wire color issue then.

this EEC harness has nothing to do with the fuse box harness grafting work i did to upgrade it as well to a 5.0L application.


I really need opinions.

I am testing for the presence of 5v and less than a volt on the TPS center tap in in a few.

the first pic is the MAP sensor connector.

the second pic is the EGR (left ) and TPS (right) connectors.

I think two things...................
this was an assembly line screw up that was "made to work"
or
Ford had a short fall on certain color wires during that day and used what they had.
at the end of the day,, if it has continuity to where it belongs,, it will work, i just need to dospoogeent it in my son's EVTM.


scott
304 772 3411

Hi Scott,

The harness I used on my Turbo Coupe came out of my 87 Sport Coupe and the colors are orange, green, black. If I remember I used the green to check voltage and ground the other lead on your meter,
1987 Turbo Coupe, 306, Trick Flow Track Heat heads, Comp Cam, Trick Flow Pistons, Eagle Rods, Center Force clutch, T-5, 8.8 w/373 gears, and a bunch more

EVTM help request

Reply #5 –
well well well...............

so i dospoogeented the evtm with the color conflicts, i will add the note *93* EVTM as the source vehicle for this wire change.

I really wish i could undo the grommet and inspect the splices... last thing i want to know is that there are butt splices vs solder.

Im hoping if its a dealer swap in, that they at least soldered.


Mike,
is it standard for shops to solder from your past experience?

it appears that the job was done good enough to not be obvious that hands were in there so i am hoping.

the wiring all tones out fine, and resistance comes to Zero ohms,, so,, the last thing i could check is voltage drop before the splice and then at the far end of each suspect color wire except for the ref ground lead.

EVTM help request

Reply #7 –
i'll roll the dice then,
the car did increase in fuel as i increased the throttle body idle screw so that tells me the tps must be in the game. 
i dont think the tweecer has the MkVIII maf tables loaded yet so thats a huge part of this initial testing that is muddling up my expected results as in what i hear and see.

in order to get the car to run smooth,, my tps center tap at idle was sitting right at 1.3vdc there abouts...........  it certainly wont start and run idle on its own without manually assisting the gas pedal.