engine stumbles at cold start.

half_twisted · Post by **half_twisted** » Tue Oct 23, 2007 1:38 pm

I just started to notice the engine stumbles at cold starts... I just replaced the batt about 1 month ago, spark plugs like 3 months ago along with msd wires.. I also checked the spark pugs to make sure they were on tight. and it wont go away any idea what it could be.. also notice the engine idleslower than the usual..

half_twisted · Post by **half_twisted** » Wed Oct 24, 2007 12:49 am

anyone here have an idea what it could be at.

latief · Post by **latief** » Wed Oct 24, 2007 10:19 am

I would think spark plug wires but your already changed that,

how many miles on the car ?

spark plugs gap?

could be a bad sensor somewhere, maybe a clogged cat, or even a bad thermostat ?

just throwing out ideas here.

good luck,

Adionik · Post by **Adionik** » Wed Oct 24, 2007 11:35 am

Someone correct me if im' wrong....but I believe your Idle is supposed to drop around 500 at stop lights and stuff.

Other than that, i'm having the same problem with a cold start.

Post by **occasional demons** » Wed Oct 24, 2007 12:28 pm

When it first fires does it briefly rev to 1500 rpm (aprox.) then settle to idle? Or does it start but stays at 500ish? The AIC normally opens up when keyed on. With the hood open you can hear it. It then closes when engine starts, that's why it has that surge to around 1500, then settles to idle. If it isn't doing that then possible IAC. That was one of the things that gradually occured when mine died. It was sort of nice actually not having the motor rev like that on startup.

half_twisted · Post by **half_twisted** » Wed Oct 24, 2007 7:00 pm

the gap on the spark plugs are at spec.
at cold start the car idle is really low. it never surges up high or anything. It kinda feels like a missfire or wet plugs at start for about 3-5 seconds.

oh and how could a bad thermostat effect how the engine starts.. I just bought a 180 thermostat from autozone since ive been wanting to get one for a while now..

latief · Post by **latief** » Wed Oct 24, 2007 7:51 pm

half_twisted wrote:the gap on the spark plugs are at spec.
at cold start the car idle is really low. it never surges up high or anything. It kinda feels like a missfire or wet plugs at start for about 3-5 seconds.

oh and how could a bad thermostat effect how the engine starts.. I just bought a 180 thermostat from autozone since ive been wanting to get one for a while now..

I am by no means an expert on this, but if the thermostat is faulty, or stuck open, they engine will take a longer time to warm up to normal operational tempreture in the morning, i actually had that happen in a previous car and it did hesitate slightly in the morning..

half_twisted · Post by **half_twisted** » Thu Oct 25, 2007 12:48 pm

well the car warms up just fine but since i did buy a 180 temp thermostat ive had laying around I migh tas well put it in this weekend.

yellowpatrol · Post by **yellowpatrol** » Thu Oct 25, 2007 5:09 pm

Possibly coil pack?

aperson · Post by **aperson** » Fri Oct 26, 2007 1:53 am

What do you mean stumbles? Like it's about to shut down then goes to normal idle? If so sounds like an IAC problem to me. Or do mean that if only fires of a few cylinders then starts up? If its not starting right then it could be cam/crank sensors, Coil pack, fuel pump, fuel lines leaking, and worse case scenario PCM.