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1991 Lincoln, Multiple problems, related?

1K views 4 replies 0 participants last post by  Arthur Dent 
G
#1 ·
1991 Lincoln, Executive Series, front-wheel drive, 3.8 V-6, 138,000
miles

Several questions...

1) Intermittent "CO" message in the fuel guage area. What possible
malfunction(s) does this refer to?

2) Oil pressure readout goes low, intermittent. Returns to "normal" after a
period of time which varies. Bad sensor, wire or ground?

3) Motor runs fine with no load, in "park" and "neutral", and on dyno in
drive, accelerates through entire range with no problems, but seems to
misfire during actual road use under light to moderate acceleration.
Depending on speed when this occurs, the misfire or skip can range from a
single miss to multiple occurences which feel like the shudder of very
out-of-balance tires (at highway speeds). Motor smooths out immediately if
accelerator is released. This occurs even if overdrive is locked out. Oil
pressure goes low, but I should think that this is to be expected and
unrelated to #2.

Recent work: Car was parked for about 18 months, after A/C
compressor seized. Was driven approx. 3 miles with no serpentine belt.
Shortly before that, distributor was replaced during "routine" tune-up when
cap screw snapped off in housing and attempts to drill and tap destroyed the
"ear".

Since resuming use of the car, both fron axles were replaced (CV
joints bad), ball joints and control arms replaced (worn), A/C compressor,
serp belt and battery replaced. (I don't think any of these are related,
included for completeness.)

I'm not a complete moron when it comes to cars, but the majority of
my experience comes from before computerized motor control and fuel
injection. (Give me a 1970 AMC Ambassador with a 360 4bbl and an unlimited
supply of gasoline and it would never see a profesional mechanic...damn, I
miss that car.)

Thanks for your consideration.
 
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G
#2 ·
"Arthur Dent" <uce@fcc.gov> wrote in message
news:azvGf.2491$Sb.528@trndny03...
>
> 1991 Lincoln, Executive Series, front-wheel drive, 3.8 V-6, 138,000
> miles
>
> Several questions...
>
> 1) Intermittent "CO" message in the fuel guage area. What possible
> malfunction(s) does this refer to?

[I don't have a clue here]
>
> 2) Oil pressure readout goes low, intermittent. Returns to "normal" after
> a
> period of time which varies. Bad sensor, wire or ground?

[most likely bad sender unit]
>
> 3) Motor runs fine with no load, in "park" and "neutral", and on dyno in
> drive, accelerates through entire range with no problems, but seems to
> misfire during actual road use under light to moderate acceleration.
> Depending on speed when this occurs, the misfire or skip can range from a
> single miss to multiple occurences which feel like the shudder of very
> out-of-balance tires (at highway speeds). Motor smooths out immediately if
> accelerator is released. This occurs even if overdrive is locked out. Oil
> pressure goes low, but I should think that this is to be expected and
> unrelated to #2.

[could be misfire due to plugs, plug wires, or dirty /defective fuel
injectors]
>
> Recent work: Car was parked for about 18 months, after A/C
> compressor seized. Was driven approx. 3 miles with no serpentine belt.
> Shortly before that, distributor was replaced during "routine" tune-up
> when
> cap screw snapped off in housing and attempts to drill and tap destroyed
> the
> "ear".
>
> Since resuming use of the car, both fron axles were replaced (CV
> joints bad), ball joints and control arms replaced (worn), A/C compressor,
> serp belt and battery replaced. (I don't think any of these are related,
> included for completeness.)
>
> I'm not a complete moron when it comes to cars, but the majority of
> my experience comes from before computerized motor control and fuel
> injection. (Give me a 1970 AMC Ambassador with a 360 4bbl and an unlimited
> supply of gasoline and it would never see a profesional mechanic...damn, I
> miss that car.)

[sorry about your AMC- what happened to it?]
>
> Thanks for your consideration.
>
>
 
G
#3 ·
Arthur Dent wrote:
>
> 1991 Lincoln, Executive Series, front-wheel drive, 3.8 V-6, 138,000
> miles
>
> Several questions...
>
> 1) Intermittent "CO" message in the fuel guage area. What possible
> malfunction(s) does this refer to?
>
> 2) Oil pressure readout goes low, intermittent. Returns to "normal" after a
> period of time which varies. Bad sensor, wire or ground?
>
> 3) Motor runs fine with no load, in "park" and "neutral", and on dyno in
> drive, accelerates through entire range with no problems, but seems to
> misfire during actual road use under light to moderate acceleration.
> Depending on speed when this occurs, the misfire or skip can range from a
> single miss to multiple occurences which feel like the shudder of very
> out-of-balance tires (at highway speeds). Motor smooths out immediately if
> accelerator is released. This occurs even if overdrive is locked out. Oil
> pressure goes low, but I should think that this is to be expected and
> unrelated to #2.
>
> Recent work: Car was parked for about 18 months, after A/C
> compressor seized. Was driven approx. 3 miles with no serpentine belt.
> Shortly before that, distributor was replaced during "routine" tune-up when
> cap screw snapped off in housing and attempts to drill and tap destroyed the
> "ear".
>
> Since resuming use of the car, both fron axles were replaced (CV
> joints bad), ball joints and control arms replaced (worn), A/C compressor,
> serp belt and battery replaced. (I don't think any of these are related,
> included for completeness.)
>
> I'm not a complete moron when it comes to cars, but the majority of
> my experience comes from before computerized motor control and fuel
> injection. (Give me a 1970 AMC Ambassador with a 360 4bbl and an unlimited
> supply of gasoline and it would never see a profesional mechanic...damn, I
> miss that car.)
>
> Thanks for your consideration.



CO = Circuit Open. A bad ground or fuel sender can cause this, as can the fuel
float's rheostat going past its normal range.

Oil pressure varying can be any of the three named, as well as a bad gauge. It
could also be actually happening; stick a mechanical gauge in the oil sender
port to check it.

For misfire & rough running, could need tune-up (plugs, wires, etc.), vacuum
leak, or maybe IAC or EGR valve.

INVEST in a $35 digital code reader and pull codes to help pinpoint the
problem(s).
 
G
#4 ·
"Ted" <tedreaves@charter.net> wrote in message
news:xwyGf.98$2H6.34@fe06.lga...
>
> > 3) Motor runs fine with no load, in "park" and "neutral", and on dyno in
> > drive, accelerates through entire range with no problems, but seems to
> > misfire during actual road use under light to moderate acceleration.
> > Depending on speed when this occurs, the misfire or skip can range from

a
> > single miss to multiple occurences which feel like the shudder of very
> > out-of-balance tires (at highway speeds). Motor smooths out immediately

if
> > accelerator is released. This occurs even if overdrive is locked out.

Oil
> > pressure goes low, but I should think that this is to be expected and
> > unrelated to #2.


> [could be misfire due to plugs, plug wires, or dirty /defective fuel
> injectors]


Plugs and wires are new and timing was checked and good. I've been leaning
towards the fuel injection as being off, but it seems odd to me that the
symptoms would not be present under all conditions, especially on the dyno.
I did run injector cleaner through it, but I don't put much faith in canned
repairs.

> [sorry about your AMC- what happened to it?]


Blew a lower radiator hose on a hot Saturday night about 10 miles outside
the city limits of Killeen, TX (Back before it got built up like it is now)
on the way to the dirt track. By the time I walked back to town the parts
store was closed and didn't open until Monday. When I got the hose and
walked back out there the car was gone. THP had towed it and it was "in
storage" for more than a week by the time I found out what had happened to
it- the storage charges were more than I could afford to pay and I never got
it back.
 
G
#5 ·
"Sharon K.Cooke" <scooke@cox.net> wrote in message
news:43EAC78C.CDF7BD97@cox.net...
>
> CO = Circuit Open. A bad ground or fuel sender can cause this, as can the

fuel
> float's rheostat going past its normal range.


Ah, thanks, the owners manual mentioned it but didn't explain what it meant,
and my Chilton's manual didn't mention it at all.

> Oil pressure varying can be any of the three named, as well as a bad

gauge. It
> could also be actually happening; stick a mechanical gauge in the oil

sender
> port to check it.


Good idea.

> For misfire & rough running, could need tune-up (plugs, wires, etc.),

vacuum
> leak, or maybe IAC or EGR valve.


Plugs and wires were replaced just before the compressor seized. Vacuum leak
sounds like a good possibility, as a family of squirrels was living in there
before I bought it, and chewed some other stuff, maybe they got a vacuum
line too.

Would it pull more vacuum under load than when parked or on the dyno?

> INVEST in a $35 digital code reader and pull codes to help pinpoint the
> problem(s).


Will do. I was going to buy one a couple of years ago but didn't.

Thanks much.
 
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