Weird Electrical Problem??

D

dwhiskie

New Member

Sep 18, 2004

183

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0

Oct 23, 2004

#1

• Oct 23, 2004

• #1

Ok,Had a new 308 put in awhile back and had nothing but problems getting it to run right.Over the last couple months have made progress but still not there.The strange thing is,when I set the tps using green and blk wires,I cant get it to read a steady # but if I ground the blk wire to 1 of the screws that mounts the tps I can get it to set right and as soon as I take that ground wire off it goes back to random #s.I got the ground from -bat to engine and chassi,a ground from back of head to firewall,a the orange wire from wiring harness grounded to a different bolt on drivers side head and the ground from eec to inside chassi under the carpet.Am I missing something here.I just cant figure this out.The last engine (stock) I had ran fine.Any ideas

 

D

dwhiskie

New Member

Sep 18, 2004

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Oct 23, 2004

#2

• Oct 23, 2004

• #2

bump

 

dastang2

Active Member

Dec 11, 2003

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tx

Oct 23, 2004

#3

• Oct 23, 2004

• #3

if it is ground you need why not just keep it grounded to that screw and drive it like that. i am not to good with efi but sounds like you got a short somewhere.

 

D

dwhiskie

New Member

Sep 18, 2004

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Oct 23, 2004

#4

• Oct 23, 2004

• #4

Because if the signal return "blk wire" isnt right I wonder what else isnt functioning right.I kinda think its running in limp mode and am trying to get some suggestions as to why.I lost as to why

 

I

Idwitheld-1`

New Member

Nov 30, 2003

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Portland Oregon

Oct 23, 2004

#5

• Oct 23, 2004

• #5

You should have +5 vdc from orange to black on the TPS. If you have no ground on the black, the TPS will not work correctly. In fact the green will show +5vdc, this is wide open throttle to the computer and it will enritchen the mix, hence it will NOT run correctly at idle. I would measure out at the EEC to verify you are connected correctly. Most probable is you are disconnected elsewhere. I would not add a separate ground. You want to use the factory supplied ground as this is a REFERENCE voltage. You want to tie into the EEC designeated grounding point on this circuit.

 

tmoss

Gettin Wired

Founding Member

Jun 28, 2001

7,153

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Saint Louis, MO

Oct 24, 2004

#6

• Oct 24, 2004

• #6

Your ground circuit is compromised somewhere - you need to bite the bullet and find it. It can be a tough task, but check every connector and ground point.

 

D

dwhiskie

New Member

Sep 18, 2004

183

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Oct 24, 2004

#7

• Oct 24, 2004

• #7

How do I find out what wire on the eec is for the tps,and where are all these conector ground points,how do I find them?

 

J

jerry beach

Founding Member

May 20, 2002

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Ocala,FL

Oct 24, 2004

#8

• Oct 24, 2004

• #8

dastang2 said:

if it is ground you need why not just keep it grounded to that screw and drive it like that. i am not to good with efi but sounds like you got a short somewhere.

Click to expand...

I am thinking that you said to test drive the car this way. Thats exactly what I would do. Either that or run a new ground wire to the EEC ground terminal in the car. If it fixes your flutuating TPS voltage then make a permanent solid connection and ditch the old one. I have to agree with what tom said, dont use just any old ground. I dont see how it could make a difference, but he knows his stuff.

 

tmoss

Gettin Wired

Founding Member

Jun 28, 2001

7,153

32

128

Saint Louis, MO

Oct 24, 2004

#9

• Oct 24, 2004

• #9

dwhiskie said:

How do I find out what wire on the eec is for the tps,and where are all these conector ground points,how do I find them?

Click to expand...

I have color wiring diagrams and wiring loom diagrams with ground points at:


www.veryuseful.com/mustang/tech/engine