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1990 Fleetwood
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Discussion Starter #1
Howdy

A friend has a 1990 Fleetwood that has sat for 3 years without use. I'm trying to get it back into good shape, and driving it around for a few weeks during that process. Just 58k miles on it.

First things I did : new battery (old one was dead), changed out oil, new gas, changed out coolant.

First 400 miles, mostly great. 25 mpg highway, 18 mpg around town. Only hiccup: one night, coming up my long steep driveway, it lost most power, and barely made it up. Didn't repeat that.

Next 100 miles: all of a sudden losing power, and running rough, as if some cylinders not firing. Going over a steep local mountain pass, that it had handled happily previously at 50 mph, had to go down into D1, and was reduced to 30 mph. MPG dropped down from 22 avg. to 10.7.

Made it home, phew, and now it's time to diagnose and fix.

First thing I did was try to pull codes, per the sticky in this forum. No codes showed up, but the numbers 8.8.8 and then 0.7 showed up. The SERVICE VEHICLE SOON and SERVICE ENGINE SOON lights were lit. Perhaps I made some error in executing the code pulling technique ??

Picked up new spark plug wires, coil, plugs, distributor and rotor, and getting ready to install those.

Found an official shop manual on eBay, ordered it, and it should show up early next week.

Going to check fuel pressures after installing all those new parts.

All thoughts invited from veterans of these fine vehicles.

-- stan
 

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92 Fleetwood 2dr cpe - FWD, 96 Seville SLS, 02 Seville
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1,016 Posts
I have a couple of posts on reclaiming my 92 Fleetwood.

Had the same symptoms, it was the injectors that failed.

But also, rerun your hill tests with a full tank. There are plastic baffles in the tank that are meant to keep fuel near the fuel pump. These are known to degrade with time. Car on hill could could allow fuel to "slip" away from pump.
 

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1990 Fleetwood
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10 Posts
Discussion Starter #3
Thanks muchly Sefiro, I'll check out your 92 Fleetwood recovery posts.

> the injectors that failed

Wouldn't surprise me that that might be the case here. Do you remember which particular brand of injectors you installed ?
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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20,097 Posts
I have a couple of posts on reclaiming my 92 Fleetwood.

Had the same symptoms, it was the injectors that failed.

But also, rerun your hill tests with a full tank. There are plastic baffles in the tank that are meant to keep fuel near the fuel pump. These are known to degrade with time. Car on hill could could allow fuel to "slip" away from pump.
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it was the injectors that failed
YUP - 1990 was the first year for multi-port injection
and fuel injectors were a big problem/common failure -

use a stethoscope - or similar - and listen to each injector for that distinct CLICK as they fire -
a faint click - or no click points to a failed injector -

go with the rebuilt - matched flow - 4-hole BOSCH injectors -
around $90 for the set on ebay -
you'll get a small increase in power AND a small increase in gas mileage over the stock 1-hole injector -

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the broken fuel tank baffles were also a well-known problem -
symptom was "running out of gas" during cornering with 1/4 tank of gas -
 

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92 Fleetwood 2dr cpe - FWD, 96 Seville SLS, 02 Seville
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Ditto 4 hole bosch. Tried a couple of aftermarket original type and they failed relatively quickly so I replaced all of them with a matched bosch set.
 

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1990 Fleetwood
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Discussion Starter #6
Thanks so much, Basscat, and again Sefiro.

Ordered that $90 matched Bosch set off of eBay earlier this evening.

Will get out the stethoscope tomorrow and give a listen.

In my day job, I diagnose computer software and hardware issues. Always fun to play with a car.

Just tried to get the codes again. Got an E12 and E96. Time to look those up.
 

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1990 Fleetwood
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Discussion Starter #7
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the broken fuel tank baffles were also a well-known problem -
symptom was "running out of gas" during cornering with 1/4 tank of gas -
LOL .... one more data point in my strong belief that nobody should be allowed to engineer automobile systems until they've spent a decade or more as a mechanic ....
 

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1990 Fleetwood
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Discussion Starter #8
Just tried to get the codes again. Got an E12 and E96. Time to look those up.
Found those E codes here : https://www.cadillacforums.com/forums/ht4100-4-1-4-5-4/21558-obd-i-codes-4-x-engines.html

E12 - No Distributor Signal

Going to be replacing the distributor cap and rotor tomorrow. I imagine that what is there has been there since the git-go.


E96 - Torque Convertor Overstress

I'm guessing that comes from when I had to go into D1 to get over a steep mountain twice yesterday, going to a job and then coming back home, and barely made it at that, with speed of 30 mph.
 

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92 Fleetwood 2dr cpe - FWD, 96 Seville SLS, 02 Seville
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Both of those may be secondary symptoms of the misfire/low idle. They may go away once the mIsfire is fixed
 

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'93 Regal coupe ('91 Fltwd coupe previously)
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434 Posts
Damn.. you ordered the set I wanted! What's likely is you also need to have the exhaust completely replaced. If the fuel injectors were leaking, your catalytic converter has probably hallowed itself out and has clogged your muffler up. I would have blown my motor if I kept driving it the way it was, if I could even get it to start just before having replaced the exhaust completely. Here's what I did: https://www.youtube.com/watch?v=rDqOeVt-rjs. I also, perhaps stupidly, had the cat replaced without having the injectors done yet.
 

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70 Deville 78 Seville 92 Deville 03 Deville
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821 Posts
It sounds like a clogged catalytic converter to me. I would do a vacuum check. A bad MAP is slow to throw a code. I just read a thread here recently where a guy had a bad MAP sensor and didn't get a code at all.
 
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