cold start stumble....

QWKSNKE · 09-30-2005, 07:01 AM

Anybody else expereinced this.

Basically any time my car is started up cold, it stumbles when going down the road (kinda like an old carb car). Clears up after about a block of driving. My car started this a month or two after the old tune was done (before the 60# injectors)

Italian LX · 09-30-2005, 07:09 AM

My car has just about always done the exact same thing since I have been modifying it. It always seemed worse when it gets colder. If I let the car idle for a couple minutes or so, it usually won't do it. But like you said, it clears up after a few blocks.

I've never really paid attention to trying to fix it, but if there is a cure, I'd be willing to go with it. I've just had too many other things to work on to worry about that.

Dale McPeters · 09-30-2005, 07:17 AM

What is the ECT/ACT reading when this happens?

boss96 · 09-30-2005, 08:40 AM

Go to scalars, "manifold volume", reduce the value a few points and see if it helps. If not, then increase the value and check again. It is used as an accelerator pump and will fix that problem.
Bob

boss96 · 09-30-2005, 08:43 AM

Wait a minute, I mixed you up with another user on eectuning.org that has the same user name but has a 96 cobra.
In your case I'm not as familiar with the eec in your car, look for something that controls accelerator pump function, you should have that and again, that is what you need to change.
Bob

Dale McPeters · 09-30-2005, 09:08 AM

Bob,

Glad you are still around...

In the above cases it could also be when the EEC just starts to make the transition from OL fuel to CL fuel based on the ECT/ACT tables/functions or the ISC/ECT function or O2 switching.
That is one of the reasons I asked about the temps......

QWKSNKE · 09-30-2005, 09:35 AM

Quote:

Originally Posted by boss96

Wait a minute, I mixed you up with another user on eectuning.org that has the same user name but has a 96 cobra.

Bob

yeah I saw that awhile back. Freaking geek stole my name !!!

Dale McPeters · 09-30-2005, 09:45 AM

Also look at your startup fuel table as it is based on time instead of ECT/ACT as you did not specify an amount of time......and I do not know how long it takes you to drive a block....

QWKSNKE · 10-01-2005, 06:14 PM

your revision helped the stumble a little bit. It wasn't as bad this morning as it usually is.

Dale McPeters · 10-01-2005, 07:20 PM

Lee,

Take a look at the file I sent back to you versus what you sent me and you can see the items that I "tinkered" with, may need a just a little more. You may also want to zero out the 35 sec row in the FN1306 - Fuel Table - Startup. Just like I did on the 45 sec. row.

09-30-2005, 07:01 AM	#1
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	cold start stumble.... Anybody else expereinced this. Basically any time my car is started up cold, it stumbles when going down the road (kinda like an old carb car). Clears up after about a block of driving. My car started this a month or two after the old tune was done (before the 60# injectors) __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

09-30-2005, 07:09 AM	#2
Italian LX Daddy x4 ...we're done Join Date: Dec 2004 Location: Oxford, AL Posts: 11,551	Re: cold start stumble.... My car has just about always done the exact same thing since I have been modifying it. It always seemed worse when it gets colder. If I let the car idle for a couple minutes or so, it usually won't do it. But like you said, it clears up after a few blocks. I've never really paid attention to trying to fix it, but if there is a cure, I'd be willing to go with it. I've just had too many other things to work on to worry about that. __________________ -Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring

09-30-2005, 07:17 AM	#3
Dale McPeters 5.0 Block/Walnut Cracker Join Date: May 2005 Location: Working.... Posts: 2,409	Re: cold start stumble.... What is the ECT/ACT reading when this happens? __________________ '14 Dodge Challenger SRT8 392 6-speed

09-30-2005, 08:40 AM	#4
boss96 Member Join Date: May 2005 Posts: 47	Re: cold start stumble.... Go to scalars, "manifold volume", reduce the value a few points and see if it helps. If not, then increase the value and check again. It is used as an accelerator pump and will fix that problem. Bob __________________ 1996 GT, forged parts, vortech, ZXA3 processor, etc.

09-30-2005, 08:43 AM	#5
boss96 Member Join Date: May 2005 Posts: 47	Re: cold start stumble.... Wait a minute, I mixed you up with another user on eectuning.org that has the same user name but has a 96 cobra. In your case I'm not as familiar with the eec in your car, look for something that controls accelerator pump function, you should have that and again, that is what you need to change. Bob __________________ 1996 GT, forged parts, vortech, ZXA3 processor, etc.

09-30-2005, 09:08 AM	#6
Dale McPeters 5.0 Block/Walnut Cracker Join Date: May 2005 Location: Working.... Posts: 2,409	Re: cold start stumble.... Bob, Glad you are still around... In the above cases it could also be when the EEC just starts to make the transition from OL fuel to CL fuel based on the ECT/ACT tables/functions or the ISC/ECT function or O2 switching. That is one of the reasons I asked about the temps...... __________________ '14 Dodge Challenger SRT8 392 6-speed

09-30-2005, 09:45 AM	#8
Dale McPeters 5.0 Block/Walnut Cracker Join Date: May 2005 Location: Working.... Posts: 2,409	Re: cold start stumble.... Also look at your startup fuel table as it is based on time instead of ECT/ACT as you did not specify an amount of time......and I do not know how long it takes you to drive a block.... __________________ '14 Dodge Challenger SRT8 392 6-speed

10-01-2005, 06:14 PM	#9
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	Re: cold start stumble.... your revision helped the stumble a little bit. It wasn't as bad this morning as it usually is. __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

10-01-2005, 07:20 PM	#10
Dale McPeters 5.0 Block/Walnut Cracker Join Date: May 2005 Location: Working.... Posts: 2,409	Re: cold start stumble.... Lee, Take a look at the file I sent back to you versus what you sent me and you can see the items that I "tinkered" with, may need a just a little more. You may also want to zero out the 35 sec row in the FN1306 - Fuel Table - Startup. Just like I did on the 45 sec. row. __________________ '14 Dodge Challenger SRT8 392 6-speed