Stalling/Hesitation
 

A while ago I was having issues with stalling and hesitation after the car had idled cold for a bit, I'd put it in gear and it would start sputtering and would die if I didn't hit the gas. Would also idle bad for a bit on a warm start. I cleaned the MAF and disconnected the battery to reset the computer. After that it was ok for a while.


Now recently I'm noticing the hesitation coming back. I seems to be on a cold start, the car idles for maybe 5 minutes and then i'll put it in gear and it'll start to sputter. Right now its not as bad as it was before. Any ideas as to what else it might be? Right now I just put a can of seafoam in.

Keane, I can't say I know what it is, only ideas from past experience. Mine is doing the same thing. I know for me it is related to the Cold Weather. Mine started the first time the outside Temps dropped below 25°. It gets better, not fixed but better when the Temps are higher than 30°…
But I'm thinking it's a bad Plug, Plug Wire, or injector. Mine never dies. But it acts like a cylinder is misfiring randomly. Nothing else would explain it.

When I had my Firebird I went threw a bad winter in Waukeegan, about 50 miles north of Chicago and on the western coast of Lake Michigan. Well, the Cold froze and cracked 3 of my wires and my distributor cap and coil. This stuttering is the same symptoms as what my Firebird was doing. I haven't checked it out yet but your symptoms and Mine are very similar. So I would check first for and stored MIL codes, then the condition of your wires, plugs, injectors and coils!
Hope this helps you! :thumbsup:

I was talking to Keane about the usual suspects of this problem, but we need more ideas.

I'm curious if your MAF is just a problem, since cleaning it worked for a little bit.

Does it feel like the gas pedal "sticks" for the first press or 2 after it sits for a while?

Heres my 2 cents...

Since it seems to idle ok ... Maybe possibly with the colder temps.. Isnt the TPS suppose to help compensate for the change from idleing in neutral to be in gear? Maybe the TPS just needs to be removed cleaned and replaced?
Over time grit dirt, and old grease will have a tendancy to get "crispy"(inside) in colder temps.. thus causing it to not operate properly... I would recommend taking it off cleaning it thoroughly... re-lube it lightly..(white lithium grease) and replacing it to see if that doesn't resolve your problem. considering you said you have to give it throttle right away in order for it to stay running in gear.

You may also want to perform the cleaning process with the idle air control as well it may also have picked up some debris over time... Since you said its also problematic even on warm starts.

Like MIke (Chibi) mentioned... since cleaning the MAF worked temporarily
It too maybe at the point of needing replacement? Is your current MAF an AC Delco? If not that may also be the problem..

Hope this helps Keane...
Let us know what cured the problem...:thumbsup:

The TPS shouldn't be the issue, I think you meant the IAC valve. The TPS just simply reads the angle the TB is open.

The IAC is a valve, it can sometimes get caked with carbon and stick, but it's not the most common of issues on these cars.

Check IAC, PCV, plugs, wires, fuel pressure, etc

edit: don't forget to check for vacuum leaks and check the EGR

Mike,
I just figured with the colder temps we have all experienced lately... Maybe possibly its a combination of everything... Cant hurt to try anyway...:thumbsup:

You know as well as I do anyplace there's even a small amount of moisture it will have a tendency to freeze... Especially around anything electrical sealed unit or not... At least that my outlook on things... Makes me glad mines currently in storage.. lol

Heres another thought...
Maybe theres a bunch of moisture/frozen ice particles or even dirt that inside the intake tube thats contaminating the MAF? I mean how often do we take it off and actually clean it? Maybe the Intake tube has a crack in it? That could also cause idle/running issues? When mine was cracked... I definitely had some idleing and running issues... due to the inconsistent airflow and varying temps from outside air being pulled in VS underhood temps... Just another wild thought in this definitely cold weather.

the MAF sensor I'm pretty sure is original to the car, gas peddle doesn't feel sticky or anything. If I can get a video of it I will. Only thing that sucks is its really just too cold out to do much work.

I really want to blame the MAF on this issue myself but I'm just not sure. Seems to happen primarily when the car is cold....
I suppose part of the trick is figuring out if it's not getting air, fuel or spark. Based on the symptoms, my gut says it might be air related (doesn't mean my gut is right).

I apologize in advance if I regurge something already mentioned....
- I know this was mentioned, definitely check for any vac leaks.
- 03SSLE has posted diagnostics for the MAF before using a volt meter. THis might be a perfect time to try that info out.
- Have the ICM tested at a local parts store.
- If possible, I think removing the throttle body might be wise. Clean up the backside of it from any gunk.
- While the TB is off, also clean up the IAC nice and good. Re-clean the MAF.
- Pull the air filter out, make sure nothing crazy is stuck in the pleats (snow, ice, neighbors lost dog, etc).
- Inspect the temp sensor (normally found in the air intake duct, make sure it's not all frosty).

I think this winter has been crazy for all of us and harder on our cars then normal. Today, my Grand Am sounded funny when it first ignited. Then I had to listen to the power steering pump have a tiny whine in it until it warmed up (I've had that happen on cars before when put to enough of a deep freeze). So some of this could be out of the norm just due to the insane cold temps.

With mine it definitely has something to do with the cold. I think my car is allergic to temps below 35 degrees. When the weather has warmed up the stutter is not as bad. I'm still going to check it out. But I'm allergic to temps below 65 degrees. Hopefully all my issues will be taken care of by the end of march. Then it's on to tackle "The Lexus"