Voltage drop killing engine?

[Strikeking10]

Ive been trying to rule out everything I can before I try messing with the tune, the car has been face planting once in a while coming up to a stop in neutral, it doesnt always do it but ive just gotten used to downshifting to prevent it. The car sat for 2 years and had to have the Motorcraft battery replaced, the shop put in a Interstate battery but I noticed coming up to a stop as its trying to die the voltage drops and when I had it at our Ford dealership getting a suspension noise looked at the battery tested low as well.

Can a drop in voltage be causing it to die? Ive already put a new oem IAC on and it didnt change. Im trying to leave the dashpot settings for last if I can. Is there anything else that it could possibly be?

 

[decipha]

if it didnt do it before and the only variable is the battery then that would be suspect

a drop in voltage does cause more load on electrical components, how low of a voltage drop are you seeing?

have u verified no vac or air leaks? After sitting a while those rubber lines can deteriorate developing cracks and the like which could very well be the culprit

do u witness any excessive lean out on decel?

 

[SVTdreamin04]

Yes, voltage drop can do this. When my alternator was having issues, my car would randomly die. I replaced the alternator and no more issues with dying at an idle


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[hotcobra03]

how often is it happening during the drive,

it can be so many things..

mine,,I drive alot, every now and than I get a stall feel,or idle swing,
age,,,

but when I had bad stall issue,like tsb..

coils were the cause..been years now and never a stall like that

 

[Strikeking10]

if it didnt do it before and the only variable is the battery then that would be suspect

a drop in voltage does cause more load on electrical components, how low of a voltage drop are you seeing?

have u verified no vac or air leaks? After sitting a while those rubber lines can deteriorate developing cracks and the like which could very well be the culprit

do u witness any excessive lean out on decel?

the times I have witnessed it, it dropped down to low 11's and I havent seen it lean out that I remember, but I have seen it go rich.

how often is it happening during the drive,

it can be so many things..

mine,,I drive alot, every now and than I get a stall feel,or idle swing,
age,,,

but when I had bad stall issue,like tsb..

coils were the cause..been years now and never a stall like that

its not every time but I can make it happen by doing a pull and letting off then putting it in neutral to coast.

 

[SVT_Troy]

You need to data log the car while driving around so you can capture that moment of stumble. Posting the log should be able to help people here help you figure out a direction.


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[hotcobra03]

the times I have witnessed it, it dropped down to low 11's and I havent seen it lean out that I remember, but I have seen it go rich.



its not every time but I can make it happen by doing a pull and letting off then putting it in neutral to coast.

this is just like the stall issue,minus the pull..

what happens under normal stop like say from 60mph .

I only touch clutch when I must..so most of the time I'm still in gear while slowing..

for a coil test..1st thing I recall was a slight jerk when in 6th under 50mph.

when trying to slightly accelerate just to keep with the flow..
and than in sub divisions,trying to stay quiet on pedal..jerk here and here,,
it would come and go..but it did get to a point you knew something was up..never a code,

found issue, by using 8 other coils from a local member..just testing.

 

[Strikeking10]

this is just like the stall issue,minus the pull..

what happens under normal stop like say from 60mph .

I only touch clutch when I must..so most of the time I'm still in gear while slowing..

for a coil test..1st thing I recall was a slight jerk when in 6th under 50mph.

when trying to slightly accelerate just to keep with the flow..
and than in sub divisions,trying to stay quiet on pedal..jerk here and here,,
it would come and go..but it did get to a point you knew something was up..never a code,

found issue, by using 8 other coils from a local member..just testing.

Coming to a stop from 60mph will kill it if I just put it in neutral and coast so ive just been down shifting to prevent it.

 

[MalcolmV8]

Is this an ongoing problem? or suddenly developed? It can be a tune issue but if it just appeared out of no where then obviously something else.
Ford themselves had an issue with this when these cars first came out. Mine was one of them doing it brand new back in the day.

 

[Strikeking10]

Is this an ongoing problem? or suddenly developed? It can be a tune issue but if it just appeared out of no where then obviously something else.
Ford themselves had an issue with this when these cars first came out. Mine was one of them doing it brand new back in the day.

It started after I got my car back from the shop, I got a base tune sent to me from Justin at VMP and we only had to change a couple things, it run great besides that. I tried to datalog it today since we had some nice weather but I cant get Livelink to work for whatever reason, it just says its not responding and then closes the app. ive tried re installing it a couple times with no luck.

 

[MalcolmV8]

It started after I got my car back from the shop, I got a base tune sent to me from Justin at VMP and we only had to change a couple things, it run great besides that. I tried to datalog it today since we had some nice weather but I cant get Livelink to work for whatever reason, it just says its not responding and then closes the app. ive tried re installing it a couple times with no luck.

Ah. I'd get the data logging working and then work with Justin to see what's going on. Even if it turns out to not be in the tune he should be able to point you in the right direction based on the logs.

 

[Acunamatata]

Mine does it every now and then. My tuner thinks it's the tb shutting down.

# 1339

 

[me32]

How is the alternator? Also did the tsb ever get done on the car prior to tuning?

 

[Strikeking10]

How is the alternator? Also did the tsb ever get done on the car prior to tuning?

The alternator had been rebuilt and they upgraded it but it was about 2 years ago when it first went into the shop and I forgot what they did exactly, and I forgot to say it does have a 3.2" pulley as well not sure if that would affect it though

 

[me32]

The alternator had been rebuilt and they upgraded it but it was about 2 years ago when it first went into the shop and I forgot what they did exactly, and I forgot to say it does have a 3.2" pulley as well not sure if that would affect it though

Should be good. But never hurts to check the charging with a meter. At the battery and at the alt.