Camaro cold start issues
03-10-2019, 07:53 PM
#1
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Camaro cold start issues Hey guys, have been experiencing some odd behavior on cold starts with my 2002 Camaro SS for a while and finally getting around to asking about it. I will start off by saying that the car is a garage queen and will sit for several weeks at a time. Basically what happens is I will go to take it out for a cruise and the car will initially fire right up and idle normally, but when I put it in D, it will stall out. Most of the time it starts right back up on the first try, but there has been times like today where it cranks and cranks and cranks and I have to do 2-3 cycles with the key for it to turn back over.
Any ideas as to what this could be? I replaced the battery not long ago and the voltage reads within the normal range. I was thinking it could be tune related, but it actually did this before I had all the mods/tuning done. Car runs strong and will start up every time after it is driven for a little bit and warms up. Not sure, any advice is appreciated!
Any ideas as to what this could be? I replaced the battery not long ago and the voltage reads within the normal range. I was thinking it could be tune related, but it actually did this before I had all the mods/tuning done. Car runs strong and will start up every time after it is driven for a little bit and warms up. Not sure, any advice is appreciated!
03-10-2019, 09:48 PM
#3
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I thought about that as well. But it doesn't make any whining noise or anything and the car has low mileage (32k) so I thought maybe not, but I will look at the pressure. I guess anything is on the table at this point.
03-11-2019, 01:24 PM
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When I read this part:
...my very first thought was the same as LLLosingit - fuel pressure and/or pump check valve issues. But then I read the following:
If the pump is bad enough to cause stalling at cold idle then I would expect it to likely exhibit some issues under load and/or when warm as well. The check valve could still be failing even if operating pressure is strong (causing the hard restarts/need for several key cycles), but that wouldn't explain the stalling issue....unless there's a second problem which is not related to the pump. I wonder if there is an MAF related issue here?
Have you checked for stored/pending codes (even if no SES is present)?
Have you checked fuel trims?
Checking fuel pressure is still a good idea based on the symptoms, if nothing else just to rule it out. You'll want to check it under load as well, plus leave the gauge connected for a while after engine shut down to see if it holds pressure (and how much) for a period of time.
If fuel supply is weak, it could certainly cause the stalling and hard restarts, but a flooded engine can also behave in a similar way. When you experience one of those hard restarts, have you ever tried holding the throttle wide open (clear flood mode) during cranking?
Basically what happens is I will go to take it out for a cruise and the car will initially fire right up and idle normally, but when I put it in D, it will stall out. Most of the time it starts right back up on the first try, but there has been times like today where it cranks and cranks and cranks and I have to do 2-3 cycles with the key for it to turn back over.
Have you checked for stored/pending codes (even if no SES is present)?
Have you checked fuel trims?
Checking fuel pressure is still a good idea based on the symptoms, if nothing else just to rule it out. You'll want to check it under load as well, plus leave the gauge connected for a while after engine shut down to see if it holds pressure (and how much) for a period of time.
If fuel supply is weak, it could certainly cause the stalling and hard restarts, but a flooded engine can also behave in a similar way. When you experience one of those hard restarts, have you ever tried holding the throttle wide open (clear flood mode) during cranking?
03-11-2019, 10:10 PM
#6
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When I read this part:
...my very first thought was the same as LLLosingit - fuel pressure and/or pump check valve issues. But then I read the following:
If the pump is bad enough to cause stalling at cold idle then I would expect it to likely exhibit some issues under load and/or when warm as well. The check valve could still be failing even if operating pressure is strong (causing the hard restarts/need for several key cycles), but that wouldn't explain the stalling issue....unless there's a second problem which is not related to the pump. I wonder if there is an MAF related issue here?
Have you checked for stored/pending codes (even if no SES is present)?
Have you checked fuel trims?
Checking fuel pressure is still a good idea based on the symptoms, if nothing else just to rule it out. You'll want to check it under load as well, plus leave the gauge connected for a while after engine shut down to see if it holds pressure (and how much) for a period of time.
If fuel supply is weak, it could certainly cause the stalling and hard restarts, but a flooded engine can also behave in a similar way. When you experience one of those hard restarts, have you ever tried holding the throttle wide open (clear flood mode) during cranking?
...my very first thought was the same as LLLosingit - fuel pressure and/or pump check valve issues. But then I read the following:
If the pump is bad enough to cause stalling at cold idle then I would expect it to likely exhibit some issues under load and/or when warm as well. The check valve could still be failing even if operating pressure is strong (causing the hard restarts/need for several key cycles), but that wouldn't explain the stalling issue....unless there's a second problem which is not related to the pump. I wonder if there is an MAF related issue here?
Have you checked for stored/pending codes (even if no SES is present)?
Have you checked fuel trims?
Checking fuel pressure is still a good idea based on the symptoms, if nothing else just to rule it out. You'll want to check it under load as well, plus leave the gauge connected for a while after engine shut down to see if it holds pressure (and how much) for a period of time.
If fuel supply is weak, it could certainly cause the stalling and hard restarts, but a flooded engine can also behave in a similar way. When you experience one of those hard restarts, have you ever tried holding the throttle wide open (clear flood mode) during cranking?
I actually did some running around in it today and it was fine
I guess I will check fuel pressure and scan it for codes and report back.
03-27-2019, 07:56 PM
#7
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Hey guys, just wanted to update this. I am waiting to start a new job and have some time off so I've been messing with the car. I haven't had a chance to check for fuel pressure but did check for codes and nothing came up. However, the strange thing is that the car has not been acting up. I drove it 3 days in a row and it didn't hiccup whatsoever. I'm not sure, maybe this is related to it sitting for long periods of time without a battery tender. No idea, guess I'll revisit this if it occurs again or gets worse. Anyways just wanted to update, thanks for all the help!
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03-28-2019, 02:36 PM
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Not on an '02 car like TransAmWS.6's. 
Based on the update, it's possible that somewhat low battery voltage on a cold start might cause the isolated idle weirdness that the OP is describing; PCM memory for learned parameters might become incomplete or corrupt if voltage was low enough during cranking, etc. I've occasionally seen a similar low idle condition (only in gear) on my '98 after sitting for long periods, especially if battery voltage had gotten a bit weak while sitting. Just like the OP mentioned, mine has always cleared up with a simple restart, only difference is I haven't experienced any sort of stalling or the long cranking periods/difficulty restarting associated with the occurrence of this low idle. So there still might be a separate, also intermittent issue that's causing those other conditions for the OP.
Based on the update, it's possible that somewhat low battery voltage on a cold start might cause the isolated idle weirdness that the OP is describing; PCM memory for learned parameters might become incomplete or corrupt if voltage was low enough during cranking, etc. I've occasionally seen a similar low idle condition (only in gear) on my '98 after sitting for long periods, especially if battery voltage had gotten a bit weak while sitting. Just like the OP mentioned, mine has always cleared up with a simple restart, only difference is I haven't experienced any sort of stalling or the long cranking periods/difficulty restarting associated with the occurrence of this low idle. So there still might be a separate, also intermittent issue that's causing those other conditions for the OP.
03-30-2019, 09:07 PM
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RPM and wssix99 I appreciate you guys. Another small update. I ended up taking it to the drag strip last night, car actually stalled on me after I did a burnout. Its like the sudden drop in RPM's after doing a burnout was too much and it killed it, did this twice actually. Car did the same thing as I described before, hard slow start and idled low for a couple seconds, then everything was back to normal. I am actually starting to think this could be tune related. Does that sound like a reasonable guess at this point? Only thing that makes me second guess is that the car runs so strong. No cutting out or breaking up like its hurting for fuel or anything.
03-31-2019, 12:59 AM
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RPM and wssix99 I appreciate you guys. Another small update. I ended up taking it to the drag strip last night, car actually stalled on me after I did a burnout. Its like the sudden drop in RPM's after doing a burnout was too much and it killed it, did this twice actually. Car did the same thing as I described before, hard slow start and idled low for a couple seconds, then everything was back to normal. I am actually starting to think this could be tune related. Does that sound like a reasonable guess at this point? Only thing that makes me second guess is that the car runs so strong. No cutting out or breaking up like its hurting for fuel or anything.
Wonder if the IAC is part of the problem? This certainly wouldn't be my first guess for a problem like hard starting/long cranking periods alone, but it could certainly be a factor in the other aspects of this condition.
03-31-2019, 05:42 AM
#13
First check your chassis grounds, and all grounds for that matter. If that don't do it, do a smoke test on the intake. Sounds like you could have a periodic vacuum leak. (something loose) Retorque all on the intake and throttle body. Smoke test will tell you. Unless its a plastic intake and its internal.