88 LeSabre won't start when cold

[fribergb]

All,

Yes, it's old... but it runs great and starts like a champ when it's above 50 degrees... and I've already installed a heater in the garage but the weather can change pretty quick here in CO and I hate to be stranded....

It coughs and gags and backfires up through the air filter when it tries, and if I don't mind putting a year's worth of wear on the starter I can usually get it started after trying for ten minutes or so. But when it's warm it starts immediately!

Do any of you know what componant I would replace first to solve this? It already has a new fuel pump and the gas is clean... new alternator and new battery... new fuel filter...

Thanks much!

-Bryan

[pcv]

Seems like the perimeters of one or more of your vehicle sensors is changing when the temperature drops. To get around it, I'd scan the vehicle when cold to determine which sensor is fault. I suspect the coolant sensor but I could be wrong.
Another thing could be that you may need is the basic, tune up.
Do you have spark and fuel when the vehicle refuses to start? If you have both, replace the spark plugs.
The temp over here is around -20C and vehicles have been towed due to no start and all my guys have been doing is dry the cylinders and plugs and start the vehicle.
Good Luck.

[RABarrett]

This is likely an issue of fuel pressure. I recommend, under any circumstances, to have the problem properly diagnosed. Remembering that the fuel demand rises as temps drop, the fuel pressure issue would be the first place to look. If the vehicle has over 60,000 miles on the pump, it merely raises the probability of pump problems. Ray

[buddytopdog]

I have 202,000 miles on my 3.8 motor and have the same problem. Slowly changing sensors. Crankshaft position sensor,fuel pressure regulator Egr valve, etc. Cleaned idle control motor. Could be coolant sensor. Replaced fuel pump and sending unit awhile ago. New fuel filter too. Have always used premium gas since 140,000 miles. I still get 25 mpg on the highway at 55 mph in Pennsylvania. Wouldn't start for a week. Changed two year old spark plug wires and is starting better but, not like it should. First start of the day, I tuen key off and on three times and then it will start. Also, have a new starter and oil sensor guage put on. Oil sensor lets fuel pump know there is pressure built up. Hope this helps. I plan on getting new coolant sensor next or another engine pretty darn soon.

[1989Buickguy]

I had the same problem on my 89. Changed wires and plugs, now it's ok. Camshaft sensor is inoperative due to magnet falling out, but it runs ok. Starts right up in cold weather now.

[RABarrett]

Something to consider here, guys, is the timing chain issue in these engines. These engines are prone to eating timing chains. As they wear, they become increasingly out of time. If the fuel pressures are up to par here, I suggest remembering this fact. You might possibly save the engine; some of them are interference. Ray

[O.P]

I have the same problem and continue to battle it as we speak, I've replaced crank sensor, coolant sensor, fuel pressure regulator, plugs, wires, fuel pump and it still back fires thru the air filter on the first cold start of the day. After it starts the first time, it will runperfect. Until it cools off.

[buickmastermind]

"This is likely an issue of fuel pressure. I recommend, under any circumstances, to have the problem properly diagnosed. Remembering that the fuel demand rises as temps drop, the fuel pressure issue would be the first place to look. If the vehicle has over 60,000 miles on the pump, it merely raises the probability of pump problems."
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Not a chance!

The issue is with the ignition/spark plugs and wires. Some ignition coils, when old or poor quality, fail to work under certain temperaturs.
Also, as was said before, the motor does have a timing chain issue, but that only applies to the 86-87 3.8l v6. The timing chains, when they would jump a notch, would make it so the valve heads hit on the cylinder heads, and get bent. That was the reason for the upgrade to the less powerful, less efficient 3800.

[jwe124]

Originally Posted by buickmastermind

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Not a chance!

The issue is with the ignition/spark plugs and wires. Some ignition coils, when old or poor quality, fail to work under certain temperaturs.
Also, as was said before, the motor does have a timing chain issue, but that only applies to the 86-87 3.8l v6. The timing chains, when they would jump a notch, would make it so the valve heads hit on the cylinder heads, and get bent. That was the reason for the upgrade to the less powerful, less efficient 3800.

Thank goodness for this message. My mom's 89 LeSabre exhibits the same problems in the winter time. My dad still swears up and down it's the fuel pump. Yet, he's changed it at least 5 times since we got the lemon in 1999. He still swears up and down it's the fuel pump since allegedly there was a faulty design causing a weak pressure, flooding and hard starting.

I knew it was something else because his explanation made no logical sense.

[keepingitontheroad]

I have a '90 Lesabre with 211,000 miles. Exhibits the same problem, will not start when cold. Depending on how cold, it will either eventually start after cranking a while (spitting and coughing through the air filter) when mildly cold to it won't start at all untill the engine is heated up when really cold. Speaking of backfiring through the air filter, I actually blew a hole through the top of the air filter housing and had to replace. If I plug in the block heater it starts no problem, when its warm it starts no problem. Once the car is started it runs fine. Has anyone that has posted to this thread who has had this problem been able to solve. I have changed wires and plugs more than once.

[keepingitontheroad]

I have a '90 Buick Lesabre with 211,000 mile with the same problem. If mildly cold, around freezing, will start after cranking for a while. The car coughs and backfires through the air filter while trying to start (in fact I actually blew a hole through the top of the air filter housing and had to replace). When cold the car will not start period, until the engine is warmed, either by plugging in the block heater or bringing inside to heated garage. When the weather is warm or the block heater has been plugged in it starts no problem and runs fine. I have replaced wires and plugs more than once. Has anyone with this problem who has posted here been able to solve?

[buickmastermind]

Same thing I stated above about the coils. You also might want to make sure the battery has the correct voltage when cold. When it runs, is it smooth, or does the motor vibrate?

[rustbucket]

Sounds to me like the spark timing. Anyone replace the cam sensor?

[buickmastermind]

It isn't the cam sensor because the computer only uses the reading from it after the motor has warmed up.

[rustbucket]

My manual says that below 400 rpm (cranking) the spark is controlled by the crank sensor and the ICM. Above 400 the ICM yeilds spark control over to the computer. It must use all the appropriate sensors to control the spark. If the cam sensor is goofy till warm up, it could cause the problem. I wouldnt rule it out.