Cold Start Stumble
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Cold Start Stumble
For the last few weeks, my car has been stumbling when cold. If the outside air temp is below about 70 degrees, it gets downright ignorant with me at times!
It throws a code - 43 - then goes away. I do need to reset the computer... that may be an old stowed code.
However, when it is cold, I go to accelerate, it kinda hesitates a bit.
Any ideas?
I have installed a new opti, EGR and O2 sensors.
Thanks!
It throws a code - 43 - then goes away. I do need to reset the computer... that may be an old stowed code.
However, when it is cold, I go to accelerate, it kinda hesitates a bit.
Any ideas?
I have installed a new opti, EGR and O2 sensors.
Thanks!
Instructor
Joined: Oct 2000
Posts: 206
Likes: 0
From: Nashville, Tn. 37211 TN.
Re: Cold Start Stumble (bogus)
You can also check your vacuume lines to the EGR switch and valve. Had the same problem but after replacing all vacuume lines, switch and valve it went away! Dont know if the EGR set up is the same on your car.
[Modified by Camvette, 3:57 PM 8/16/2001
[Modified by Camvette, 3:58 PM 8/16/2001]
[Modified by Camvette, 3:57 PM 8/16/2001
[Modified by Camvette, 3:58 PM 8/16/2001]
Melting Slicks
Joined: Aug 2000
Posts: 2,618
Likes: 5
From: Overland Park KS
Re: Cold Start Stumble (bogus)
I had what I thought were cold start problems on my 95. Every couple days it would get worse and worse. Seemed okay after that initial morning start up. Eventually it began to have trouble all the time and it turned out to be my starter. It doesn't sound like your problem but starters can be very trickey to diagnose.
I'd look at your fuel delivery first though, being you have trouble starting when cold and hesitation when you give it gas.
When you say stumble does it start to turn over or do you just get a tick?
We need as much description as possible.
I'd look at your fuel delivery first though, being you have trouble starting when cold and hesitation when you give it gas.
When you say stumble does it start to turn over or do you just get a tick?
We need as much description as possible.
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: Cold Start Stumble (KCvetteowner)
It starts. It is not the starter... it works fine. The stumbles start after the car has started. It takes a high (1000 rpm) idle.
then, after 30 seconds or so, I tap it down, and drive off. It just drives rough and sorta coughs a bit.
I hope this defines it better....
Oh, code 43 is knock sensor... but I still think it is an old code.
[Modified by bogus, 8:21 PM 8/16/2001]
then, after 30 seconds or so, I tap it down, and drive off. It just drives rough and sorta coughs a bit.
I hope this defines it better....
Oh, code 43 is knock sensor... but I still think it is an old code.
[Modified by bogus, 8:21 PM 8/16/2001]
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: Cold Start Stumble (bogus)
This could be caused by vacuum leaks or the engine coolant temp sensor. The coolant sensor maybe lying about the temperature of the engine. Compare the digital coolant temp reading with the digital oil temp and the outside air temp in the morning before you start the car. The three temps should be with in 10 degrees of each other. If the ECT (on the waterpump) is showing a higher temp, try reseating the connector to it.
The vacuum leaks maybe caused by loose intake bolts an throttle body bolts. I 'd have the intake bolts retorqued in sequence and the throttle body bolts.
Fuel filter should be replaced if its got 25000 miles or more on it.
The vacuum leaks maybe caused by loose intake bolts an throttle body bolts. I 'd have the intake bolts retorqued in sequence and the throttle body bolts.
Fuel filter should be replaced if its got 25000 miles or more on it.
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: Cold Start Stumble (AquaMetallic94LT1)
Aqua,
thanks for the tips. I will check them. I need to do the intake anyway, so I will be able to fix that at the same time.
You mention the temp differences - you make a good point. I will check those. there is a difference, but I am not sure if it because I notice it later in the day and all is warmed up!!!
the fuel filter is new. I put it in back in may or so.
thanks!
thanks for the tips. I will check them. I need to do the intake anyway, so I will be able to fix that at the same time.
You mention the temp differences - you make a good point. I will check those. there is a difference, but I am not sure if it because I notice it later in the day and all is warmed up!!!
the fuel filter is new. I put it in back in may or so.
thanks!
