Starting my car on an incline trouble.

[PeterZarolli]

Recently I needed a new battery in my 09 Matrix. This fixed my issue of it stuttering to start but I still get a feeling like it is low on power briefly but only when parking it on an uphill incline like my driveway. Almost like the RPMS are low just for a second. Before the battery was replaced the whole car and ignition cycle felt like it was going to die but then evened out. When it is sitting level it starts fine but on the driveway, there seems to be a slight delay or momentary loss of power. Not nearly as bad as before where it felt like the whole car was going to die.

Since I have only noticed it on an incline I ask if this is normal for an older car? Again it starts fine no problems when level.

 

[Oillover]

How much fuel is in the tank?

 

[PeterZarolli]

How much fuel is in the tank?

Full tank

 

[eljefino]

Try cleaning your throttle body, then disconnect the battery again so it relearns.

You could still be undergoing relearning of the idle from the previous disconnect.

 

[benjy]

check-replace any fuel filters + a fuel pump pressure test as well. try the cheap DIY first then visit your local indy pro if needed, good luck

 

[nascarnation]

Any chance this is slippage in the transmission? Could it be taking a bit of time to charge up the torque converter due to possible low oil level causing aeration / draindown of the torque converter when stopped?

Easy way to tell on the converter is to park on the incline and do a restart immediately after shutting it off. Then do a restart after being parked for hours on the incline. And compare the performance of the two conditions.

There are seals inside the transmission that are more prone to allow fluid drainback from the converter as they age but work fine when the transmission is operating. If this is your root cause, it's not necessarily something to worry about, just realize what is happening.

 

[PeterZarolli]

Any chance this is slippage in the transmission? Could it be taking a bit of time to charge up the torque converter due to possible low oil level causing aeration / draindown of the torque converter when stopped?

Easy way to tell on the converter is to park on the incline and do a restart immediately after shutting it off. Then do a restart after being parked for hours on the incline. And compare the performance of the two conditions.

There are seals inside the transmission that are more prone to allow fluid drainback from the converter as they age but work fine when the transmission is operating. If this is your root cause, it's not necessarily something to worry about, just realize what is happening.

Ive done that test before and yes even on an incline after starting for the first time it will start fine. Leave it to sit on an angle and it does the thing. Does the torque converter work when the car is starting? I never get any problems when shifting gears etc.

 

[nascarnation]

The top half oil volume of the torque converter will drain out due to gravity when the engine is not running. How fast this happens depends on how tight the seal is between the input shaft and the converter internals. If you look at a side view of a converter, you can visualize how it can drain out (down to the level of the center hub) into the inside of the transmission housing.

When the engine starts up, it takes a bit of time (usually just a few seconds) for the pump to refill the converter volume full of fluid. In that condition, the converter internal vanes are "slicing" air rather than oil and don't transmit torque. Once the converter is full and pressurized by the pump, it stays that way until the engine is shut off.

This is the reason that oil level in automatic transmissions are typically measured with the engine running, rather than shut off like engines are, because the amount of drainback from the converter vs time shut off is a big variable. The converter depending on size, can hold 2 to 4 quarts.

 

[Number_35]

@PeterZarolli, I assume your driveway slopes up, and you're parking nose-in.

What about backing in, so the front of the car is down, and seeing what difference it makes?

 

[wheelman1991]

Any chance this is slippage in the transmission? Could it be taking a bit of time to charge up the torque converter due to possible low oil level causing aeration / draindown of the torque converter when stopped?

Easy way to tell on the converter is to park on the incline and do a restart immediately after shutting it off. Then do a restart after being parked for hours on the incline. And compare the performance of the two conditions.

There are seals inside the transmission that are more prone to allow fluid drainback from the converter as they age but work fine when the transmission is operating. If this is your root cause, it's not necessarily something to worry about,

To me this sounds like hesitation with the engine itself, not related to the transmission. Op stated his RPMs drop to a low idle, and then back up to normal.

 

[D60]

My neighbor swears his '00 Cavalier had trouble starting after parked nose high and it was due to the fuel pump. It happened to him in ABQ and there was a "mechanic" (I'm not sure what this means) across the street who diagnosed it as such.

He insisted I replace the pump, which I did as a favor (I owe him), but I was VERY leary of the diag and gently voiced my concerns. The problem has not returned months later, but I'm still thinking it's 99% coincidence.

If you think about how a closed, pressurized system works, a slight angle shouldn't make any difference. If the nose were pure vertical like a well pump, maybe? But still, you're pumping gasoline rather than water.

 

[nascarnation]

To me this sounds like hesitation with the engine itself, not related to the transmission. Op stated his RPMs drop to a low idle, and then back up to normal.

Good point.
You know the old saying "If the only tool you have is a hammer, everything looks like a nail"?
After 25 years of working with automatics, my first inclination was to start with that.

 

[vwmaniaman]

Maybe there is water in the tank and it settles near the pump intake when parked on the hill. Maybe try a bottle of HEAT in there. Could be a cheap fix.

 

[Donald]

I remember parking my Jeep on an incline when the starter was broken. Let it roll a bit and pop the clutch. Who needs a starter.