intermittent problem when cold
#26
Member
Thread Starter
Join Date: 03-04-07
Location: Hellertown PA
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
Well it happened again this morning. One thing that is consistant with last time is it rained. I didn't think it rained the first time it happened, but if I think back it did. I just didn't drive it for a couple days after it rained. That's where it gets weird. So everytime it happened it rained at night. Come morning it ran like crap for a little. So you would say something is getting wet and causing the problem. Thing is I can drive it in a downpour (like I did last night) and have no problems whatsoever. I can let it sit for a couple hours and it's still fine. It's only after it rains and I let it sit for 8+ hours that it'll act up. AND even if it stops raining it'll do the same thing for about 3-4 days after. That doesn't make any sense to me AT ALL!
#27
Senior Member
Join Date: 02-27-07
Location: Houston, Tx
Posts: 984
Likes: 0
Received 0 Likes
on
0 Posts
Well it happened again this morning. One thing that is consistant with last time is it rained. I didn't think it rained the first time it happened, but if I think back it did. I just didn't drive it for a couple days after it rained. That's where it gets weird. So everytime it happened it rained at night. Come morning it ran like crap for a little. So you would say something is getting wet and causing the problem. Thing is I can drive it in a downpour (like I did last night) and have no problems whatsoever. I can let it sit for a couple hours and it's still fine. It's only after it rains and I let it sit for 8+ hours that it'll act up. AND even if it stops raining it'll do the same thing for about 3-4 days after. That doesn't make any sense to me AT ALL!
#28
Senior Member
Join Date: 05-03-06
Location: new jersey
Posts: 4,638
Likes: 0
Received 0 Likes
on
0 Posts
Well I've been having a problem with my POS cobalt lately. When it sits for a while (like 8+ hours) and I get in and drive i've got a HUGE stumble. It starts nicely, can rev it pretty smoothly...but as soon as I put it in 1st and try to pull out it stumbles BADLY and backfires/pops out the exhaust. It's hard to get it up fast enough to 2nd gear. When I shift into 2nd it's the same thing. It'll do this for a couple minutes and then clear up pretty quickly and drive fine for the rest of the trip. Let it sit for a long time and it's the same thing again. A problem with this is I scanned it (no check engine), and no current dtc's (of course with no light), no pending codes or history codes either. It also doesn't do it all the time. It'll do it for a couple days then stop for a couple weeks. Then it's back again for a day or so etc. so it's hard to take it to the dealer for warranty work since I don't know if it'll do it for them. Anyone have any problems like this? It's an 05 w/12300 miles on it and only mods are stage 2 and air box mod.
#29
Member
Thread Starter
Join Date: 03-04-07
Location: Hellertown PA
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
I did, but since it didn't act up during the time there and no dtc's I got a clean bill of health. And I removed the whole thing for the airbox mod. But since I can drive it all day in the rain with no problems, let it sit then problems, they go away after it's warm, and let it sit again DRY for the next couple days and it'll still act up ONLY when first started after a longgg period, I wouldn't lean too far into that. But I guess you never know. BTW, I've had federwell cai's in my gtp, air filter right off the ground with no box on a supercharged lt1 and various others and never had that happen. Who knows I guess lol. I'm also not sure if it's a rain problem yet or it's coincidence. I'll know more if it happens again with no rain.
#30
Senior Member
Join Date: 02-27-07
Location: Houston, Tx
Posts: 984
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, I don't necessarily expect that the airbox mod is your problem I was just curious. Maf sensors can be really finicky, so just keep an eye on it. One other test you could do is a fuel pressure test. Just hook up a gauge at the fuel rail and turn the key on; check if you have 50 to 60 psi and that it doesn't drop fuel pressure too quickly. A leaky injector can cause the problems you speak of; but then again there are many other possibilities as well.
#31
Member
Thread Starter
Join Date: 03-04-07
Location: Hellertown PA
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
Actually that was on my mind. I wasn't sure if these returnless systems held pressure after they were sitting for a while (hours) like the return style. My fuel pressure gauge broke so I never got to trying it. Guess I'll borrow one. Thanks for the reminder
#32
Senior Member
Join Date: 11-14-05
Location: Dumont, NJ
Posts: 997
Likes: 0
Received 0 Likes
on
0 Posts
The fuel pump runs when you cycle to the key to the "on" position. Also if there is no leak in the fuel system it should hold pressure for ever. If there was a leak you would have an extended crank after the car sat for a while.
#33
Senior Member
iTrader: (2)
Take it to the dealer and tell them to leave it over night. Go up there with them and start it, see if it does it.
Backfire usually means that its getting a lot of gas right? So it has enough gas.
What does the exhaust smell like?
Rain cant affect these cars if they're just sitting because there is no distributor to get wet nor can water get where the intake is if its just sitting.
Cracked injectors? (I think someone said) Then it doesnt happen when it warms up because heat make things expand, it might of closed up. But if it doesnt do it all the time when its cold, that might or might not be the injectors.
Lol. All of this sounds contridicting but just keep giving us an update when it happens. When, what, where. And aybe we can figure something out.
Backfire usually means that its getting a lot of gas right? So it has enough gas.
What does the exhaust smell like?
Rain cant affect these cars if they're just sitting because there is no distributor to get wet nor can water get where the intake is if its just sitting.
Cracked injectors? (I think someone said) Then it doesnt happen when it warms up because heat make things expand, it might of closed up. But if it doesnt do it all the time when its cold, that might or might not be the injectors.
Lol. All of this sounds contridicting but just keep giving us an update when it happens. When, what, where. And aybe we can figure something out.
#34
Member
Thread Starter
Join Date: 03-04-07
Location: Hellertown PA
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
I still didn't borrow the fuel gauge. I'll get it this week. I also want to see if it rains again and it does it. That way I'll know that it has something to do with it. But rain CAN in fact effect any car. You can have a cracked coil and the moisture can get in it. Chaffed wire can wick water down inside causing all kinds of problems down the line (why you never buy a flood car even if it's running fine at the time), wet maf etc. I'm 95% positive it has to do with water, but the way it goes away and comes back after it sits for a long time baffles me. Next time it does it (hopefully the rain) I'm going to take it to the dealer with all the info I came up with (yeah, like they listen to anyone anyway haha), and tell them to take it through the carwash there and let it sit till the next morning. In fact I think I'll take through a wash in the next couple days and see if that sets it off, besides I only washed it once since I've owned it
EDIT: BTW, it hasn't backfired again since the last time but it did get the bogs and smoke which smell a LOT like gas. But that doesn't mean it's ness. a fuel problem since it can be caused by running rich OR missfiring spark (unburnt fuel). I can't wait to get hpt and look at my open loop settings!
EDIT: BTW, it hasn't backfired again since the last time but it did get the bogs and smoke which smell a LOT like gas. But that doesn't mean it's ness. a fuel problem since it can be caused by running rich OR missfiring spark (unburnt fuel). I can't wait to get hpt and look at my open loop settings!
#35
Senior Member
iTrader: (2)
I still didn't borrow the fuel gauge. I'll get it this week. I also want to see if it rains again and it does it. That way I'll know that it has something to do with it. But rain CAN in fact effect any car. You can have a cracked coil and the moisture can get in it. Chaffed wire can wick water down inside causing all kinds of problems down the line (why you never buy a flood car even if it's running fine at the time), wet maf etc. I'm 95% positive it has to do with water, but the way it goes away and comes back after it sits for a long time baffles me. Next time it does it (hopefully the rain) I'm going to take it to the dealer with all the info I came up with (yeah, like they listen to anyone anyway haha), and tell them to take it through the carwash there and let it sit till the next morning. In fact I think I'll take through a wash in the next couple days and see if that sets it off, besides I only washed it once since I've owned it
EDIT: BTW, it hasn't backfired again since the last time but it did get the bogs and smoke which smell a LOT like gas. But that doesn't mean it's ness. a fuel problem since it can be caused by running rich OR missfiring spark (unburnt fuel). I can't wait to get hpt and look at my open loop settings!
EDIT: BTW, it hasn't backfired again since the last time but it did get the bogs and smoke which smell a LOT like gas. But that doesn't mean it's ness. a fuel problem since it can be caused by running rich OR missfiring spark (unburnt fuel). I can't wait to get hpt and look at my open loop settings!
Have you checked all your positive wires? One of my other vehicles did that randomly and I found a loose wire getting burned by the exhaust.
Im just throwing stuff out there trying to spark someones memory on this subject.
#36
Member
Thread Starter
Join Date: 03-04-07
Location: Hellertown PA
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
Well not a saturated MAF, but it can get moisture. If I sunk deep enough to get the maf underwater I would be having some other issues A cracked coil would probably set a missfire code if I think about it (moisture causing coil spark to ground out on whatever is close). Wires all seem to be fine, but of course I didn't go through the whole harness and check every mm of it. Just checked the parts that could chaff or burn. Thanks for the ideas though! Every idea is a new lead to something.
#37
i find that any car will run like **** when its -30 outside.. but yes i have that problem in the winter. just let it warm up to 100, thats when the heat kicks in anyway. no problem after that.
#38
Member
Thread Starter
Join Date: 03-04-07
Location: Hellertown PA
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
Thread
Thread Starter
Forum
Replies
Last Post
roth
Problems/Service/Maintenance
2
09-26-2015 12:16 PM
OrangeCoba
Problems/Service/Maintenance
0
09-25-2015 06:06 PM