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Discussion Starter #1 (Edited)
Okay, I just got my '90 Fleetwood FWD, and was handed a
shop report from the previous owner stating that the only thing
wrong with it was the catalytic converter, so I had that replaced.

So after I had the cat replaced . . . . . . .

I walked out to the car, fired it up, and it ran great . . . until the
radiator fans came on, the the car just shut off. Did that twice,
so I grabbed the codes. The car apparently ran just fine until
the cat went bad, but I'm assured that the cat went bad due to
other problems, not normal wear.

The important codes are as follows:
E016, E021, E021, E031, E038, E053, E074, E098, E099

After replacing the MAT with a new one, and the MAP from an
untouched colision car at the boneyard (I was the 1st one to
it, and it was totaled by being rear-ended), The list got a bit
shorter, and the car doesn't die when the fans come on, it
just can't decide if it's going to run smooth, rough, or die at
apparently random moments.
E016, E021, E031, E053, E074, E099

Unfortunately, E031 is still there, the MAP sensor issue.

My question is this, if I've got a bad MAP (E031) would it cause
the catalytic converter to glow red hot after 10 minutes of
idling?

Or could there be a short in the harness leading to the MAP,
causing voltage irregularities, creating the Voltage Out of Range
error (E016), among others, like problems with the TPS (E021)?

Has anyone had similar problems? I'm at a stump now. I'm afraid
I've blown out a new cat, and I don't want to dump $170 into
the car every time I try to solve a problem.

Or could my alternator be bad, making everything just go ape-
s**t?

-Dirk R.
 

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A bad MAP could cause it to run rich, causing a glowing cat. Did you clear the codes in between though? I think your car has code history, with no way to designate history from current. The TPS could cause this too, but I doubt to the extent of making the cat glow.
 

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Discussion Starter #3
What are the chances that my issue is bad wiring or alternator,
or that I've blown out the cat in the short time that I've run it?
(less than an hour total run time, over a few times running it)

Or what about a vacuum leak? Unfortunately, time spent on the
car is limited for various reasons, so research is key here. Trial
and error needs to be limited.

-Dirk R.

DaveSmed said:
A bad MAP could cause it to run rich, causing a glowing cat. Did you clear the codes in between though? I think your car has code history, with no way to designate history from current. The TPS could cause this too, but I doubt to the extent of making the cat glow.
 

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Discussion Starter #4 (Edited)
Oh yeah. How do I clear codes on a '90 Fleetwood? I've found
a few links to instruction pages here in the archives, but cannot
get any of them to load.

Any help would be appreciated. >: ^)

-Dirk R.
 

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If the cat has been glowing red it is likely toast.


Several things can make the cat glow red...way too much fuel being dumped into it, the AIR system pumping air to the exhaust manifolds all the time in combination, a severe low voltage condition due to the generator not charging correctly...this casues the ignition to start to misfire which drives the cat temps sky high as raw, unburned fuel and air is being pumped into the cat.

It sounds like some wires may have gotten pinched or shorted or something else happened in the repair that is not being detailed. Why was the car replaced in the first place?? Hard to believe all this just happened suddenly after the cat was replaced.

Did you check the fuel pressure regulator for leaking past the diaphragm...??? while idling pull the vacuum line off the fuel presure regulator and watch the vacuum nipple on the FPR for fuel leakage. There should be none. If fuel comes out the vaccum nipple with the vac line off then replace the FPR.
 

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Discussion Starter #6
Turned out to be the vaccuum line between the throttle body
and the MAP sensor. All this struggle and money over a piece
of $0.39 hose.

-Dirk R.
 
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