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Warm Start Stalling on SC400...Please Help

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Old Mar 17, 2007 | 05:42 AM
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Default Warm Start Stalling on SC400...Please Help

To begin with, I have searched and nothing really matches my problem except having a dirty TB. I thoroughly cleaned the TB and also cleaned the AIC with no luck. On cold starts, it cranks right up every time. However, if the car is driven up to temp and sits for anywhere between 10 minutes to 3 hours it stumbles and dies out. It will do this anywhere from 5-10 times and usually pegging the throttle will get it going a little quicker. The check engine light flashes and it usually stumbles for 30 seconds before dying out. I even start and get under the hood and open the butterfly on the TB with no change. I have no other symptoms like some others such as dying in traffic or any changes if the air is turned on or off. I absolutely love this car and finally have it the way I want minus the Vertex, but I hate driving it only when I know I will not have to crank it back up. Like I said, when I searched..my symptoms pointed to dirty TB, but I cleaned it for two hours. It is spotless with the no sticking on the butterfly. TPS switched out with another unit and syptoms persisted. Cleaned AIC and is functional unless an electrical connection is dying out. Please Help me.

On a positive note, I did use the "DIY Door Handle Repair" write-up and took care of that last night


Mods, if this is not the right forum, please move but I figured this did not fall under "Performance".
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Old Mar 17, 2007 | 06:13 AM
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buy a sc300 or try changing out the ecu .

Last edited by sc250tt; Mar 17, 2007 at 10:22 AM.
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Old Mar 17, 2007 | 10:20 AM
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Reset your ECU and clean out your MAF.
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Old Mar 17, 2007 | 12:32 PM
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Originally Posted by Idrewfelix
Reset your ECU and clean out your MAF.
By reseting, do you mean unplug battery connection for 5 minutes? I have not tried to clean out the MAF so I will give that a shot.
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Old Mar 17, 2007 | 12:39 PM
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Leave the battery off for a good couple of hours. For some reason its different on each car, so its better to leave it off for a long time to make sure.
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Old Mar 18, 2007 | 08:25 AM
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Originally Posted by Idrewfelix
Leave the battery off for a good couple of hours. For some reason its different on each car, so its better to leave it off for a long time to make sure.
Disconnected batter and cleaned MAF out real good last night. Now it is a little worse with a new problem. Connected everything back up and started the car, but the check engine light stayed on. Figured it may go off so brought the car up to temp, let it sit for 5 monutes, and same thing with the stalling. It has always cranked back up and stumbled, but this time would not catch and acted like it was not getting any fuel. Started back up, check engine light still on and still stumbling to a stall. Anyone?????????
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Old Mar 18, 2007 | 08:48 AM
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might not be a posotive, but this might be better atleast you can pull the code and see what the problem is.
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Old Mar 18, 2007 | 09:04 AM
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Bummer about your engine. This is probably too late to help, but here is a write up on resetting your ECU without disconnecting your battery.

http://web.ace.net.au/soarer/ecu_reset.html
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Old Mar 18, 2007 | 12:28 PM
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Originally Posted by Quick VR-4
Disconnected batter and cleaned MAF out real good last night. Now it is a little worse with a new problem. Connected everything back up and started the car, but the check engine light stayed on. Figured it may go off so brought the car up to temp, let it sit for 5 monutes, and same thing with the stalling. It has always cranked back up and stumbled, but this time would not catch and acted like it was not getting any fuel. Started back up, check engine light still on and still stumbling to a stall. Anyone?????????
Okay... How many miles are on your SC? Because it sounds to me your having a failed fuel pump now. Can you see if there is fuel being fed to your motor? (smell of gas, check fuel lines, etc).
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Old Mar 19, 2007 | 08:58 AM
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Well, looks like the ECU finally relearned so everything is back to normal. Car idles perfectly with no check engine light, but still stalls after bringing up to temp. The car itself has 139k on it, but I am not sure if a failed fuel pump would only surface during warm starts. If I peg the gas to redline, it will not die on a warm start. There is no hesitation while driving and I went 300 miles just the other day. Everything works perfectly except trying to start it after it is warmed up. Thanks for the suggestions so far, but I might need to take it to a "stealership" and see if any codes are showing up.
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Old Mar 21, 2007 | 02:38 PM
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Sounds like a bad MAF to me.. maybe find or borrow a working MAF from someone and plug that in to see if that improves anything. Sometimes, a quick whack to the MAF also resolves the issue.
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Old Mar 21, 2007 | 09:13 PM
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After more research, everything is pointing to a bad fuel pump ECU. Same symptoms others were having match mine 100%. This is also a part that most people obtained with $40 so I am going to give that a shot and see what happens.
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Old Mar 29, 2007 | 04:57 PM
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************UPDATE************

Problem Fixed

Received a used Fuel Pump ECU from GRAND_LS 4 today. Drove home from work and let the car sit an hour. Went out to start it and it slowly stalled out. Tried again just to make sure and same thing. Switched out the "new to me" ECU from GRAND and it fired right up with no problem. It was such a simple fix. Seems like there were a lot of threads without any updates so hopefully if someone has a similar problem, they will see this thread after searching.
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Old Mar 29, 2007 | 07:22 PM
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Originally Posted by Quick VR-4
************UPDATE************

Problem Fixed

Received a used Fuel Pump ECU from GRAND_LS 4 today. Drove home from work and let the car sit an hour. Went out to start it and it slowly stalled out. Tried again just to make sure and same thing. Switched out the "new to me" ECU from GRAND and it fired right up with no problem. It was such a simple fix. Seems like there were a lot of threads without any updates so hopefully if someone has a similar problem, they will see this thread after searching.
HEY BRO... Glad it worked for you!!

Its such a relief to fix a car related problem, especially when you get it done with minimal financial, and physical effort.

Still trying to figure out whats going on with mine... its at the mercy of the dealer now. I'm still waiting for that call back

Enjoy your SC brother
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Old Mar 30, 2007 | 08:24 AM
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Originally Posted by GRAND_LS 4
HEY BRO... Glad it worked for you!!

Its such a relief to fix a car related problem, especially when you get it done with minimal financial, and physical effort.

Still trying to figure out whats going on with mine... its at the mercy of the dealer now. I'm still waiting for that call back

Enjoy your SC brother
I hate your problem is still undiagnosed and your car is now at the Stealership. This was my last ditch effort then I was going to take it in for service so I am so glad I was able to avoid that. Good luck on getting yours fixed and thanks for getting mine running right
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