Cold Start Issue
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Joined: Oct 2007
Posts: 955
Likes: 10
From: Upstate NY
Cold Start Issue
Okay, so I've got a problem and I really am not sure what the hell is going on. I'll explain.
In the morning, after sitting over night, I go out and start my truck. it turns over just fine, starts, RPM's go up to 2000 RPM's, drop to 1000 RPM's slowly, then drop almost instantly to 500 RPM's. Then, almost like it's not getting enough fuel, it starts to spit and sputter, and not idle. It's been getting slowly worse. At first, it used to just idle a bit rough at first but smoothed right out. then about a week ago, I let it have it's bitch fit, but that time it stalled out. I started it back up, which it instantly fired back up, had a small hissy fit, by idling a bit rough, but went back to normal. So I decided to see what would happen if I put my foot on the throttle to see if that would change anything. Now when I put my foot on the throttle when it starts to spit and sputter, it hesitates, and continues to die, but then pics right back up.
Now, when it starts to spit and sputter I can hear the fuel pump pumping more and more, and it sometimes will recover, but on occasion like I said it stalls. The first time it stalled, the CEL came on, but then shut off again after I started it. Now, while this happens there are no CEL Codes, and I scanned for stored codes and came up with nothing. No stored codes. I imagine this to not have a code because this happens only in a cold start during Open Loop operation.
As soon as I put it in reverse to back out, it stops. this only lasts for a couple seconds, and then goes back to normal, but I've been noticing that the engine does idle a bit on the rough side. Could my rough idle issue be involved in the cold start issue?
Just so everyone is aware, this problem happens while in Park, cold morning start (Meaning it doesn't do it at all the rest of the day).
It's a 2000 4x4 4.7L auto with 45,000 miles.
I'm asking for any ideas if anyone has any, because without any code I;m not really sure where to begin. Maybe someone had something like this happen to them before? Is it a common problem? Seems strange to me.
In the morning, after sitting over night, I go out and start my truck. it turns over just fine, starts, RPM's go up to 2000 RPM's, drop to 1000 RPM's slowly, then drop almost instantly to 500 RPM's. Then, almost like it's not getting enough fuel, it starts to spit and sputter, and not idle. It's been getting slowly worse. At first, it used to just idle a bit rough at first but smoothed right out. then about a week ago, I let it have it's bitch fit, but that time it stalled out. I started it back up, which it instantly fired back up, had a small hissy fit, by idling a bit rough, but went back to normal. So I decided to see what would happen if I put my foot on the throttle to see if that would change anything. Now when I put my foot on the throttle when it starts to spit and sputter, it hesitates, and continues to die, but then pics right back up.
Now, when it starts to spit and sputter I can hear the fuel pump pumping more and more, and it sometimes will recover, but on occasion like I said it stalls. The first time it stalled, the CEL came on, but then shut off again after I started it. Now, while this happens there are no CEL Codes, and I scanned for stored codes and came up with nothing. No stored codes. I imagine this to not have a code because this happens only in a cold start during Open Loop operation.
As soon as I put it in reverse to back out, it stops. this only lasts for a couple seconds, and then goes back to normal, but I've been noticing that the engine does idle a bit on the rough side. Could my rough idle issue be involved in the cold start issue?
Just so everyone is aware, this problem happens while in Park, cold morning start (Meaning it doesn't do it at all the rest of the day).
It's a 2000 4x4 4.7L auto with 45,000 miles.
I'm asking for any ideas if anyone has any, because without any code I;m not really sure where to begin. Maybe someone had something like this happen to them before? Is it a common problem? Seems strange to me.
Veteran
Joined: Jan 2008
Posts: 368
Likes: 1
From: Burleson, TX
Been having same sort of thing happening since last year and still haven't found it. Mine has slowly gotten worse to where it does it while trying pull out of my drive way, soetimes even in the middle of the day after running in a store and like your if it dies, it will start right back up like nothing happened. When it begins to act up I can press the throttle and it will stumble, act like its going to die, then take off like a bat outta hell. Have tried several suggestions and replaced a bunch of sensors, but no fix yet. I'll keep you posted as to what I find.
Veteran
Joined: Jan 2008
Posts: 368
Likes: 1
From: Burleson, TX
I have high miles and figured I needed to replace a few sensors anyway. What I have done so far; IAC valve, map sensor, crank sensor, coolant temp sensor, TPS, IAT sensor and now cam sensor. I am planning on replacing the power steering pressure switch also. Prob cost me around $300, but I figure at least I know they are all new and with 158,000 I figure it couldn't have hurt. If the one of the sensors seems to do it I'll let you know. After these though, if I still don't find it I will have diag ran on it and let you know what I find out.
Oh yeah, I have also heard of the auto-shutdown relay doing something kinda like this, but I think the truck will always turn off, not just sputter or surge.
Oh yeah, I have also heard of the auto-shutdown relay doing something kinda like this, but I think the truck will always turn off, not just sputter or surge.