This is a WIND NOISE WARNING. Portions of this video contain heavy wind noise. Ignore this warning at your own peril, and please accept my apologies–there was nothing I could do about it at…
1988 Buick LeSabre Troubleshooting Help Wanted!
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Mass air flow sensor. If that’s gone bad the ecu will not know how much air
is entering the engine and at what temp is it. Thus unable to provide a
correct fuel to air mixture. Thus a rich condition.
I have a Tech 1, or an almost complete tech 1 in pieces around here. picked
it up at a yard sale of someone that used to work for GM for $10. never
ever had a chance to use it ever. I’ll let you know if I have it all later
on when I get another chance to look. if I do happen to have the full set,
or at least what’s essential to your needs, it’s all yours for the cost of
shipping. you have more of a use for it than I do having it just sit around.
In the meantime, you should heed +WaybackTECH ‘s thoughts on the ECU solder
joints into consideration. just pop it out and give it a good once over
with an iron and some fresh 60/40 solder, see what changes. and, good
pre-emptive maintenance in either case, even just to rule it out.
1. Have you checked the oxygen sensor(s)?
2. I remember a few years ago, my dad was taking the green Chrysler
(convertible I shared on your livestream a while back) and it went and died
on him randomly. We needed a new fuel pressure regulator, and that fixed
it. However, it still has trouble when the fuel is low. Try filling the
tank up all the way and see if that helps. My car, a 1984 Lincoln Town Car,
also has this issue when the fuel is around a quarter tank full.
3. Do you have the computer form the old cold forgotten Buick? If you did,
that would be helpful (assuming they’re both the same computer).
I would check for a plugged catalytic converter. If the dealer the
keykeeper works for has an oscilloscope (which it should), you can check
out all of the sensor signals by back-probing the sensors. I don’t think a
scan tool will give you the data you want/need. Another thing to consider,
the ECUs in these cars are famous for going bad. The two main sensors you
should be checking is the MAF and O2….they would both cause a rich
condition. Pull a wiring diagram and verify that all of the sensors have a
5 volt reference with the key turned on.
Cars just don’t age well in the upper midwest.
William,
Hmm when I had my 2000 Malibu it got a hole in the gas tank but not enough
for any gasoline leakage but enough to get bunch of water in it so when I
tried to give it alot of gas it would stall out. So when I had it on the
highway I couldn’t go no faster than 60mph. Have you checked the gas tank
for water or places where water could have gotten in?
Possibly the timing chain/belt jumped a tooth? I would check the timing
next.
Hmm…over-rich mixture, WOT needed to stay running…I would check for
clogged air filter or other restriction in the air inlet path. Also check
Mass Airflow and/or MAP (Manifold Absolute Pressure) sensor if so equipped.
try checking the actual connections at the computer , clean and re install
them and see
I’m surprised that nobody said this already but did you check the fuel
pressure regulator? Maybe these car don’t have one but I’m pretty sure all
fuel injected vehicles have them , especially a multi-port fuel injected. I
have had a bad coolant temperature sensor before and the only symptom I had
was an excessively high idle for a couple of minutes every time I started
the vehicle.
Apologies for a long post, but it’s inherent to the topic I suppose.
I’ve never worked on a 3800 Series 1, but I’ve been involved in some
unsuccessful efforts with a “cursed” 1997 Series 2 that’s been unreliable
for a couple years now. I hope this model is simpler than the Series 2.
I think my first priority would be to study everything you can find about
this car’s ignition system and diagnose that error code it gave you. The
extreme rich condition might be attributed simply to the “limp home” mode
that it’s running in. If you get that ignition fault corrected, then you
can see where things stand after that.
If you can get a Tech 1, that would be ideal since that’s what GM’s
documentation was written for. But as an alternative, you might be able to
hook this car up to a laptop serial port using some freely available
tools. One I use on a Fiero is WinALDL. Another tool some people like is
called TunerPro RT. There might be others. You can make the serial cable
yourself (there’s instructions online) or you can buy them pre-made, though
some of those are USB which I’d personally avoid.
These tools support various ECMs, possibly requiring appropriate plugin
files. I don’t know what ECM your car uses or which tools support it, but
the tools I mentioned do focus on OBD-1 era GM cars. These tools will
report sensor values such as coolant temp, O2, etc. On my car WinALDL will
report distributor reference pulses – but I don’t know if they provide
information that would be useful for diagnosing your spark module system.
I’ve never tried it on such a vehicle.
If you do replace the coolant temp sensor – I urge you to stick with
ACDelco or GM parts, not a 3rd party brand, and keep the old part for a
while – don’t just assume the new part is working correctly. I have
multiple times run into 3rd party brand sensors of various types which do
not provide accurate readings. Most recently was a CTS for the above
mentioned 1997 3800, which caused a lot of consternation until we verified
it was reporting false high temperatures. We dug the GM original out of
the trash and put it back in. That’s just one example – I’ve run into
issues with off-spec sensors multiple times on 3 different GM vehicles.
New knockoff brand sensors cannot be trusted and only compound the
confusion and problems when used. You can usually find Delco at decent
prices on RockAuto or Amazon.
Does that engine use Multec injectors? Multecs are notorious for
developing an electrical short, sometimes intermittent in nature. One
electrically shorting injector can wreak havoc with the operation of the
whole system. I suppose it’s also possible to have a couple injectors
which mechanically are flowing differently from the others when open, but
otherwise do not leak when closed. The ECM cannot compensate for
mismatched flow rates (or inconsistent fuel pressure – see below). If you
want to refresh the injectors, there are online shops that sell flow
matched refurbished injectors for much less than new replacements. But
unless there’s an electrical short then I doubt this is the car’s biggest
problem.
Fuel pressure – this should be checked with the engine running. Fuel
pressure should vary in relation to the manifold air pressure. It is the
job of the regulator to maintain a fixed pressure differential vs the
manifold – without this the ECM can’t meter the fuel injection accurately.
Rev the engine up and down and see if it’s regulating correctly. If
desired you can hook up a vacuum gauge to compare with the fuel pressure in
real time. Try loading the engine and see if the fuel pressure still holds.
If possible, hook up the fuel pressure gauge where you can watch it while
driving the car. Recreate the symptoms and see if the pressure is failing
when it happens. You might have good pressure at key on, but not be able
to maintain it under real driving loads.
All that said.. I think your ignition system trouble code is a more
definite direction to go with troubleshooting. The rest is speculative.
This is quite the challenging problem made even more so by not having the
car here to diagnose. So this is a stab in the dark. Here’s what I’d do
next if you haven’t already done so: Turn the key to full on but don’t
start the engine. Disconnect each injector and measure the voltage at the
connector.
Each injector should have 0 volts (no ground) since the CPS is not sending
a signal to the PCM. If there is any voltage at all, then I’d suspect
either a ground in the injector wiring harness (they usually fire by
switching the ground circuit) or a bad ECU, specifically the driver
section. That section is usually made up of TO-220 MOSFET’s or Bi-polar
transistors and may be able to be replaced if they’re not potted. Whatever
has failed, is not monitored by the PCM so that rules out any of the
sensors.
William, you should apologize for the lack of snow. Here in Atlantic Canada
we have received three blizzards within 4 weeks with snowfall accumulations
of 260cm or roughly 8.5 feet. Your videos are comfort food in this weather.
I had an 84 mustang that would fall all over its self because the temp
sensor though it was over heating. After a new heater core and radiator new
thermostat. And even removing the t-stat. I would watch the temp gauge max
its self till I pulled off and vented off the radiator. Then it would run
fine all day. I burped the car for hours. Never really got the problem
fixed…. Just worked with it…
Could it be a bad computer? I am not sure how much of these older cars are
controlled by the computer. If the computer was bad or going bad, I could
see why it maybe burning too much fuel as the computer maybe thinking it
needs more fuel than it actually needs, and flooding it out. Just a
thought…
I have sadly never owned a car, or driven one. I hope to some day in the
distant future. But I would rather own an old 70’s or 80’s car, rather than
a new one.
there’s a Video on Rivlanta’s Channel about the description and Operation
of the LN3 3800 (its actually from 1988) you might want to have a peek at
that video to give yourself a refresher course on how the C3I Ignition
system works.
have you checked to see if the fuel injectors are firing? It sounds like
the injectors arent firing properly. Also have you seen if you are getting
compression in the cyclinders?
Having read just about everything here and listening to you describe the
problem, what I’m about to write will probably sound like I’m just some
bumbling idiot who fell off the turnip truck yesterday. To be honest, the
first thing I thought of was the charging system of battery and alternator.
If it’s feeding the computer BesTek’s best “bad power,” wouldn’t that
cause it to do all sorts of inexplicable things like mismanage the fuel/air
ratio and report incorrect codes? You could have every sensor in the car
work properly with all wiring intact, but if the computer can’t cope with
the charging system having a “brown-out” (which could still be possible
with clean grounds and no pinched or broken wires) every symptom you
mentioned is possible, so far as I can parse it. Short in the battery?
Lack of a good magnetic field in the alternator? Remember…I fell off
the turnip truck yesterday.
Maybe it stoped maybe she fell in love with a other car or Buick and maybe
the car wanted to go back and find the car that he might had fall in love
and maybe the car wanteed to have kiss and have sex with the car LOL!!!
clogged exhaust will a make a engine lose power and not run
I immediately thought of the air filter, Could it be clogged?
Wow, you all are bound and determined to keep the Buick running!
But…I know the KK sees plenty of cheap / decent trade-in’s at his job.
Can’t he snag one for Furhead?
oh, and whats the millage? possible bad timing cam gear..
Why don’t you simply replace it with (some matching rock and roll-) music?
You are so very careful about not letting the clock bells heard, but this
with wind noise is very annoying. Please let me know before I watch, can
this be watched from beginning to end with the sound OFF?
Wasn’t the car parked outside a Baskin Robbins? (31 Flavors Baby!)
Check fuel pressure while brake torqueing engine. Foot on brake while
giving gas in gear. Could be fuel pressure drops when under load and low
fuel pressure can cause rich condition.
If 2 injector quite clean to the others and a plug being wet, I believe
your injectors are spraying too much and could do pressure drop test on
each injector. Also the vacuum fuel regulator on GM’s are good at leaking
internally into the intake and putting too much fuel in. Pull vacuum from
regulator while running and see if fuel comes from regulator. Could take a
few minutes before it appears. GOOD LUCK.
Just a thought William, have you tried revving the engine to see if it’s
straining under pressure, cuase if Furhead said it started to baulk when
driving it could be a case of the engine breaking down under load, which I
dunno if you’ve tested all the stuff with sensors etc whilst the engine is
revved and hot, if you even can do any of those things with the engine
running at higher speeds, I know bit of a stupid suggestion I mean I’m no
mechanic but nout else is coming to me just now, most of the things I can
think of aare what you’ve tried but good luck getting it fixed.
You mentioned smelling rich. Did running rich cause the catalytic converter
to heat up, melt, and block the exhaust?
Also, have you considered that the cam may have gone round? I had an 83
Impala that had low oil pressure, and eventually the cam rounded out enough
that a couple cylinders didn’t fire, it ran super rich, and I had to keep
it floored to get it home, and up the driveway.
Now, are these system shutdowns random, or can you forcibly repeat them at
any moment?
A few months ago we had a wagon that would just quit on us or suck down the
battery and idle at 30+ miles per hour, but all the connections were fine.
But, the wires had subtly corroded on the inside to the alternator and
other locations. I’m not saying that it’s battery or alternator failure,
but it might be worth your while to probe your connections and give them a
wiggle and bend for sporadic problems.
If it’s not too much of a stretch, could you show us a video of you turning
it on and it shutting down on its own? I would love to see the console,
see and hear under the hood, and know the computer operation during
operation and shutting down. If that’s not too much of a problem that
would help us out significantly. There could be something happening that
would point to a problem that is happening slowly and would require a
recording to show changes over time quickly.
I remember seeing something once upon a time on the world wide web (I
actually found the link, can you believe it:
https://www.youtube.com/watch?v=Uc9hpq9P5Os&ab_channel=Turbo231 ) about a
cable that was connected at one end to the OBD port of the car, and at the
other end to either a serial or USB port on a laptop. Paired with a program
(I believe there are a few floating around that would work) that was able
to read and display what the ECM was putting out, you could pull codes,
read live sensor data, even graph certain readouts; right through the
laptop.
Seeing as how I’ve got the Lumina, it peaked my interest greatly, but I
never did end up either acquiring a program, or a cable for it. This
perhaps could help you out as far as being able to see *some* live sensor
data, such as MAF parameters, coolant temps, throttle position, etc.
If you plan on keeping this car or have other OBD 1 autos, just purchase a
Tech! tool. Less than 300 dollars for a tool with everything you’ll ever
need. Including the software to reprogram your eeprom.
Everything’s fine, but nothing works LOL. My parents had 1988 Oldsmobile
Delta 88 which is nearly a twin to this car. The PCV did fail on that car
causing similar symptoms at one time.
Try messaging this guy, his channel is dedicated to old school vehicles (GM
mostly)
https://www.youtube.com/user/TheYoshiClan/
Can you do a video of it trying to run?
Codes would be a great help, but you don’t have to use a tech 1 only.
There are many scan tools available cheap that can read basic sensor
readings and codes. Don’t start throwing parts at it or you may compound
the problems. I also would not advise putting aftermarket parts on it.
Is the crankcase full of gas? Are the injectors being held wide open?
What was the compression on the cylinders? Have you cranked the motor with
a vacuum gauge on the intake manifold? The fuel-soaked #5 could indicate a
cracked or broken exhaust valve.
clogged catalytic converter could be the result of a bad poop make sure to
the Buick poop properly so first do a pressure test by Cadillac converter
if the pressure is different from the front and in the bank real noticeable
just like any engine you don’t want too much pressure behind the exhaust
Just throwing this out there, but I recall having similar issues with my
Olds Cutlass Ciera with a 3.3L V6. (A derivate of your 3.8L) In my case
the car would run fine until it started to warm up then run very poorly and
stop. I was at a loss and all the codes I could read pointed to a Coolant
Temperature Sensor. After replacing it and being frustrated that it wasn’t
fixed, I looked deeper. You’re going to want to find the Coolant
Temperature Sending Unit which feeds a temp reading to the ECM. Two items
named very simlarly, but if in doubt, replace BOTH of them…
Just wondering as to the status of this old, cold, but not so much
forgotten Buick.
I take back everything I said! lol Sorry Bill, not sure on that one,
sounded like the converter though.. I do know that fords of that era
have computer problems, bad caps and such. Maybe they are right! Hope
you fix it. Take care..
If the car has an exhaust pump check that. My buddy has a 91 ford bronco
that had very rich exhaust… turns out the intake and exhaust pump were
both screwed and the engine wasnt getting enough fresh air so it didnt burn
all of the fuel being injected.
Updates on the Buick problem? Curious viewer who owns a Buick.
Bill I have watched the vid it is the tps or coil pack mod that’s the only
2 thing that will stop a 3800 check the fuzes under the hood and under the
dash , that’s whats wrong so One time fuel pump relay took a crap you can
put a safty pin threw 2 wires to jump it if its the fuel pump, beat on
the bottom of tank with hammer to restart the fuel pump ps check for spark
no spark bad coil mod but I bet its tps
A uxwbill car video? I didn’t know they made those anymore! :)
Clogged catalytic converter ??? I had a car one time I had it floored and
it barely would go, took it in and they replaced catalytic converter they
said it was plugged