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Any way to check if TFI module is bad?

  • Thread starter Thread starter Chietala
  • Start date Start date Jun 11, 2007

Chietala

New Member
Sep 21, 2006
111
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0
Sacramento
Jun 11, 2007
#1
  • Jun 11, 2007
  • #1
89 5.0 with MSD Dist. wondering if is possible ti check if the module is bad?

Going through the "crank but no start" check list.
 
D

Daggar

New Member
Jul 19, 2004
3,902
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0
Jun 11, 2007
#2
  • Jun 11, 2007
  • #2
http://www.geocities.com/MotorCity/Flats/3349/test.htm
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Jun 11, 2007
#3
  • Jun 11, 2007
  • #3
Another quick method:
Put a test light across the two small wires going to the coil. Have someone crank the engine over and see if your test light pulses.
If so, the TFI is working and the coil should be firing. If this is true but there is no spark egressing the coil, think bad coil.

Good luck.
 

795.0pacecar

lover of pudgy polygamists
Jul 11, 2003
480
0
17
Senoia, GA
Jun 11, 2007
#4
  • Jun 11, 2007
  • #4
Autozone can also test it for you.
 

Chietala

New Member
Sep 21, 2006
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0
Sacramento
Jun 11, 2007
#5
  • Jun 11, 2007
  • #5
Daggar said:
http://www.geocities.com/MotorCity/Flats/3349/test.htm
Click to expand...

At the bottom of step 2 It says....

"Pull the small wire off the starter solenoid so engine will not crank. Have an assistant try to crank the engine. There should be voltage at "TFI POWER RUN(H4), TFI POWER CRANK (H3), and TACH IDM (H5)" terminals. If there is not voltages present, there is a posible wiring problem. If voltages are ok, go to step 3."

Are they wanting the assistang to crank the motor by hand? Or hold key in start position?
 

795.0pacecar

lover of pudgy polygamists
Jul 11, 2003
480
0
17
Senoia, GA
Jun 11, 2007
#6
  • Jun 11, 2007
  • #6
Hold it in the start position.
 

Chietala

New Member
Sep 21, 2006
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0
Sacramento
Jun 11, 2007
#7
  • Jun 11, 2007
  • #7
 
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