Automobile Enthusiasts

8 track mind

(1,638 posts)

18. Gotta disagree with the o2 sensor/ ignition diagnosis

Tue Dec 13, 2011, 10:21 PM

Dec 2011

No disrespect intended whatsoever.

If the O2 is malfunctioning, the computer will set a code and start ignoring it and run off of base programing. It may not run right, but it should idle. Now this is going from GM injection experience: upon cold start up, the O2 is ignored until the coolant reaches a certain temp and/or a certain amount of time has past.

I went for the conclusion of the air leak because of the high idle condition. It sounds to me like the IAC was trying to bring it under control, but couldn't quite do it and the airleak finally got progressively worse to the point that no amount of fuel could keep it lit.

That's not to say the ignition system could be at fault. I do know the Fords are famous for heat related ignition module failures, but in my experience, they wind up dying completely after giving a few symptoms. I've also seen a dead distributor cap cause some really bizarre shit, but not affecting all cylinders at once.

Just my $.02

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how can you tell if somebody has sabotaged your gas tank? [View all] Kali Dec 2011 OP

Not having seen it I can say in 94 right after I retired and drove back from right coast sce56 Dec 2011 #1

can you post the exact symptoms he was having, plus the year make and model, type of engine? 8 track mind Dec 2011 #2

89 ford PU auto, V8 4x4 Kali Dec 2011 #3

OK, gonna ask a lot of questions to see if we can get down to the bottom of it 8 track mind Dec 2011 #4

virtually no idle - won't stay lit Kali Dec 2011 #5

ahhhhh 8 track mind Dec 2011 #6

351, brakes fine Kali Dec 2011 #7

That would be a big vacuum leak. Gold Metal Flake Dec 2011 #8

hey, there you are! Kali Dec 2011 #11

im thinking this 8 track mind Dec 2011 #17

Yup, that's how you do it. Gold Metal Flake Dec 2011 #19

what is that? Kali Dec 2011 #22

holy shit is that a Y block? 8 track mind Dec 2011 #23

Dizz is out so I can prime it. Gold Metal Flake Dec 2011 #26

actually it went pretty fast when it went Kali Dec 2011 #10

Pre-1996 Ford truck trouble codes can be accessed without an expensive reader. JohnnyRingo Dec 2011 #16

Sweet! Gold Metal Flake Dec 2011 #27

is this what I am looking for? Kali Dec 2011 #28

That is the pair of test connectors Gold Metal Flake Dec 2011 #29

which hole do I jump to? Kali Dec 2011 #30

OOH! Check this link! Gold Metal Flake Dec 2011 #31

finally got them Kali Jan 2012 #33

sorry guys Kali Dec 2011 #20

It's almost never a fuel problem. JohnnyRingo Dec 2011 #9

I have to think the mechanic has really gone over it, he is a good guy and usually knows his stuff Kali Dec 2011 #12

Is it showing any codes? Gold Metal Flake Dec 2011 #13

that issue remains the same Kali Dec 2011 #14

I have an older code reader. Gold Metal Flake Dec 2011 #15

finally! Kali Jan 2012 #34

Gotta disagree with the o2 sensor/ ignition diagnosis 8 track mind Dec 2011 #18

Spit balling Gold Metal Flake Dec 2011 #21

im thinking the same thing 8 track mind Dec 2011 #24

Good point. JohnnyRingo Dec 2011 #25

codes Kali Jan 2012 #35

codes! Kali Jan 2012 #32

Good for you! JohnnyRingo Jan 2012 #36

^^ Yup ^^ Gold Metal Flake Jan 2012 #37

and on this one Kali Mar 2012 #38

Huzzah #2. Gold Metal Flake Mar 2012 #39

Spam deleted by Violet_Crumble (MIR Team) Steven_car Jun 2012 #40