First start of the day is a struggle, but only the first 00 Lesabre

buick
lesabre

#1

My 2000 Buick Lesabre has started having problems with the first start of the day. It’s not like a dead battery where the starter runs and the engine doesn’t take over. The starter goes, the engine takes over for a second, and then it quickly tapers off and shuts off.

Most of my first starts of the day are before 8 AM, but I had this happen in the afternoon on my day off as well. It usually only has one or two false starts, but yesterday I had a worrying moment where it took five or six tries to get the engine to stay on. However, once it’s started, it will start the rest of the day, even after nine hours at work. It’s just when it’s been left overnight.

I pulled a check engine code from it and it gave P0102, which translates as “Mass Airflow Circuit Low Voltage Input”.

This may be a red herring, but this morning I tried turning off the climate control while starting, and my first start was a success.


#2

The next time the vehicle sits, turn the ignition switch to the on position so the dash lights come on for two seconds without starting the engine, and then turn the ignition switch off.

Repeat this a half dozen times and then try starting the engine.

If the engine starts right off, it points to a problem with the anti drain-back valve in the fuel pump assembly.

Tester


#3

“Mass airflow sensor” is totally unrelated to the climate control system. Your experience was purely coincidence. Mass Airflow Sensor, often called the MAF sensor, is measuring the total amount of air being drawn through your air filter from the outside air. They contain within them a heating element and that does often go bad after 17 years on the road. I’m not familiar with your car, but most are really easy to access and change. It’ll be in the induction system just after the air filter box. Normally there’ll be two screws holding it on and an electrical plug. Since everything around it including its housing and the place the screws are screwed into are all plastic and there are no high torque values involved, there’s no corrosion to deal with or critical torque values. Just don’t overtighten the screws when you install the new one and strip the holes out.

Find it (try an internet search or a repair manual), try replacing it, and see what happens. If the code doesn’t clear within three or four days (some things have clear the ECU via a few repeated starts), you can return the new one for a refund and go forward.

Normally I never suggest trying a new part without actual diagnostic readings, but this one’s so simple to remove and replace and the symptoms so descriptive of normal failure of a 17 year old MAF sensor, that I’ll waive my normal self-discipline rules for myself. :grin:

NOTE: I think tester is right about the cause of the morning nonstarts. My suggestion is just for the code. If his suggestion works, you can always build the modus operandi into your morning start protocols until you feel compelled to actually get the problem fixed. I did that on an old truck once. Every morning I’d turn the key to ON for two or three 4-second moments before turning it to START. I never got around to actually fixing the problem…


#4

My Buick 03 starts well yet when putting up a window or down it almost stumbles ,
it may be a electric load condition with your car and the battery just drains enough over night yet after you run it charges to full battery and you dont have the problem until over night again. and with the battery location in these type cars way in the back seat the extra long battery cables have more resistance it could be just a loose or corroded cable .


#5

It sort of sounds like the fuel pump isn’t starting up properly when the engine is cranking. It can still starts ok w/that problem b/c of residual fuel pressure available from the past drive; but that fuel charge quickly runs out w/o the fuel pump running, and then the engine dies. It’s hard to say whether the p0102 code is related or not. A tech could test my theory of the fuel pump being the problem w/a fuel pressure test. But they’d have to have the car when the problem was happening.

Fuel pumps can fail in that manner. Tough to get started when cold, but once started and warmed up they’ll work all day. Like old people, like me. lol


#6

I’m fairly certain it’s not electrical. I just replaced the battery last year, and I watched the battery voltage on the dash display a couple times even though it isn’t acting like low voltage.

My thinking with the climate control was that, while they aren’t directly related, the ac blower running on high might be starving the engine air intake at a critical moment.


#7

Not possible. It doesn’t take its air from the same place.


#8

OP: Just a minor correction: a dead battery will not allow the starter to run at all. Nothing will happen when you turn the key.


#9

My 02 LeSabre has a similar issue. The difference being that the restart when hot is the problem. The old S.S.F.F.routine. When hot, the engine starts momentarily then acts like it’s out of fuel after a “hot soak” at least 15 minutes.
A restart with a light touch on the throttle takes care of it.
The original MAF did fail and has been replaced, twice, on spec. Fuel pressure is good. No codes. The car is low mileage at 50k plus. Problem appeared about 2 summers ago. The shop did suggest that the low speed crank sensor might be the cause. Apparently there’s a start and a run on this gadget and VERY expensive. I feel that it’s a remote possibility. But since it’s intermittent, I don’t want to throw a couple of hundred dollars at it to see if that solves it. There has been NO diagnosis that the crank sensor has an issue other than as a guess.
All work done at a certified facility over several visits. They’re as stumped as I am.


#10

On yours I’d be looking at the fuel pressure regulator. Remove vacuum line to regulator and check for the presence of fuel/ fuel vapors.


#11

Cranks but won’t reliably start , if it only happens when the engine is hot, a crank sensor failure is pretty common. Starting ok, then stalling, not as common, but the crank sensor is still a possibility. A shop might be willing to replace the crank sensor on a flier. If it fixes the problem, good to go. If not they just put the old crank sensor back in. Not sure whether a shop would do that, but no harm in asking. Having been a sort of businessman myself in the ancient past, for a reliable and mostly non-complaining repeat customer, many things are possible that wouldn’t be given to a first time customer. The problem is that it can be difficult to remove a crank sensor without damaging it.


#12

I’d be thinking fuel pump too. The fuel pump is electrical.


#13

I have done that… So has the shop guy. Pressure is ok and no leaks.


#14

Apparently it’s a major job to replace the sensor. Labor intensive and all.
Not something to be done on a whim.


#15

Well its not the pressure when its running but whether it has a problem starting at all or having pressure at start up. You’d have to have a gauge on it in the morning and see what its doing when stumbling. Doing as Tester suggested would build up pressure and get the pump going.