No Codes?

Black Sun 5.0

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Mar 23, 2002
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L.I., N.Y.
Not long ago, a mechanic tried to run diags on my '91 and came back and told me that he couldn't perform a 'running test'. What is this and what could possibly cause it. As an FYI, the problems my car experiences are as follows: idle surge, stalling, and running rich (I get 15MPG REGARDLESS of how I drive when I used to get 27MPG highway, this started before the mods began). I understand that my car can probably use a tune since modding, but my problems started before the mods. Heh, I add a cam and #24 injectors, and still get the same mileage. O2's, IAC, coolant temp sensor, etc. have been replaced. This is a good one.
 
No KOEO (key on, engine on) test is usually a bad neutral safety switch or clutch switch or associated wiring

Notice the switch in the top LH corner of the diagram. That's where the problem lies

Diagram courtsey of Tmoss & Stang&2birds.
88-91eecPinout.gif


Notice the switch in the top LH corner of the diagram. That's wher the problem lies
 

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Black Sun - it's sort of common knowledge - they won't run a KOER test if there's a clutch/neutral safety switch problem. Many who've done an engine conversion often discover it. Mine has NO clutch switch and the neutral safety switch isn't hooked up - I can't run KOER tests because of it.
 
CManT1914 said:
jrichker, do you have a diagram like this for 94/95's?
Tom (Tmoss) is the guy who does such a great job on the diagrams. I just pick them up from the site that he & Stang&2birds author. That site is http://www.veryuseful.com/mustang/tech/. Make a visit and see all the great stuff they have posted.

The only other thing that comes close is the Autozone site I sometimes use.
AutoZone wiring diagrams

http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp for 89-93 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-98 model cars
 
One last question on my part (even though I could go on with this one): I figure this is the switch that gets activated when you press the clutch down. Is it a PITA to replace? I'm only asking because I'm short on time latel and I want this fixed. Thanks.
 
Black Sun 5.0 said:
One last question on my part (even though I could go on with this one): I figure this is the switch that gets activated when you press the clutch down. Is it a PITA to replace? I'm only asking because I'm short on time latel and I want this fixed. Thanks.
I might have misunderstood you, but the clutch safety switch (part of the starter interlock circuit) and the neutral safety switch are separate.

The clutch safety switch is on the clutch arm.

The switch to fix the no-code issue is the neutral safety switch.