what exactly does...

1of2000 · Apr 26, 2005

...HOLDING THE PEDAL TO THE FLOOR WHEN STARTING YOUR CAR DO???

On about 1/2 of my starts, the car will just crank and crank and crank unless I hold the pedal to the floor, then she fires off... WTF? What could cause this, and what does the pedal actually do when you push it to the floor?

I have a Predator Chip with a custom dyno tuned burn. This problem started 6 months ago when this chip was first installed....and they don't seem to have answer for why??!

jegg · Apr 26, 2005

1of2000 said:
...HOLDING THE PEDAL TO THE FLOOR WHEN STARTING YOUR CAR DO???

On about 1/2 of my starts, the car will just crank and crank and crank unless I hold the pedal to the floor, then she fires off... WTF? What could cause this, and what does the pedal actually do when you push it to the floor?

I have a Predator Chip with a custom dyno tuned burn. This problem started 6 months ago when this chip was first installed....and they don't seem to have answer for why??!

maybe you need a new fuel pump

9646gt · Apr 26, 2005

Try turning the key on and off several times with out starting the car then start it..this will build fuel pressure back up by cutting the pump on and off ...if it fixes it try changing your filter and if that doesnt help it may be the pump..

ForPointSex · Apr 26, 2005

It stops the fuel injectors from firing. It's used when you flood the engine.

hotmustang331 · Apr 26, 2005

Hmm, usually holding it to the floor will do nothing, BUT if its durring cranking it may start spraying gas from the injectors. I dont think you would be making 450RWHP if the pump or filter was bad...however it could be a problem with the system bleeding of fuel pressure. Do like the above poster said, turn your key to ON for about 3-4 seconds then crank.

1of2000 · Apr 26, 2005

ForPointSex said:
It stops the fuel injectors from firing. It's used when you flood the engine.

this sounds more like it. i recently replaced my fuel filter. i have the external Vortech fuel pump, and i had to replace my in-tank with a 255lph pump. So could it be flooding itself when the pumps fire up? <p>
should i fast turn the ignition all the way VS. letting the fuel pressure gauge come up normal (31psi)?

1of2000 · Apr 26, 2005

hotmustang331 said:
Hmm, usually holding it to the floor will do nothing, BUT if its durring cranking it may start spraying gas from the injectors. I dont think you would be making 450RWHP if the pump or filter was bad...however it could be a problem with the system bleeding of fuel pressure. Do like the above poster said, turn your key to ON for about 3-4 seconds then crank.

see my last msg. this is what I do. I wonder if it is flooding the motor? Is this even possible??? <p> now that I think about it, this also started with the new intank pump... can you cram to much fuel in?? <p> i thought holding it to the floor was for old carburated cars??

hotmustang331 · Apr 26, 2005

Exactly, thats what you do when carbed cars get flooded, see when the car is flooded the mixture is TOO rich for the car to fireup...a bunch of fuel but no air...so when you push it to the floor it evens out the mixture, now it has alot of fuel AND alot of air then it will fire up.... but I dont think you could force enough pressure to make the injectors fire prematurly. The base idle could possable have been set too rich in that tune, but they should only spray when you start cranking, not when the key is on. This is weird...how does the car run after it cranks is there alot of gas smell and does the exhaust smell very rich?

starchman · Apr 26, 2005

I may be wrong, but what about the IAC valve?

Mike97gt · Apr 26, 2005

1of2000 said:
...HOLDING THE PEDAL TO THE FLOOR WHEN STARTING YOUR CAR DO???

On about 1/2 of my starts, the car will just crank and crank and crank unless I hold the pedal to the floor, then she fires off... WTF? What could cause this, and what does the pedal actually do when you push it to the floor?

I have a Predator Chip with a custom dyno tuned burn. This problem started 6 months ago when this chip was first installed....and they don't seem to have answer for why??!

this can be caused by the mixute being too rich for the car too start... with the throttle wide open your getting more air intot he motor making the mixture combustable..

you have a problem with your tune. i would run the stock tune untill you can get this fixed

1of2000 · Apr 27, 2005

YES!
YES, it is extremely rich. And I have an idle problem (possibly the same problem?).
My A/F Ratio on the dyno is a fairly flat 11.5 but I thought this was OK because I am trying to keep the ponies down. litterally, I had to order the biggest pulley vortech makes to detune from 490!! So the big pulley and a rich tune holds her back for my stock block. Is this a bad idea? Can I just lean it out at idle/startup?

1of2000 · Apr 27, 2005

starchman said:
I may be wrong, but what about the IAC valve?

I actually cleaned this out once, and grabbed one from the junkyard yesterday, but haven't swapped them yet.
I really think it's the tune...my car only has 50K miles on her...

jstreet0204 · Apr 27, 2005

MikeZ28 said:
you have a problem with your tune. i would run the stock tune untill you can get this fixed

He has a supercharger and presumably larger injectors. The stock tune would make it run richer.

jstreet0204 · Apr 27, 2005

1of2000 said:
YES!
YES, it is extremely rich. And I have an idle problem (possibly the same problem?).
My A/F Ratio on the dyno is a fairly flat 11.5 but I thought this was OK because I am trying to keep the ponies down. litterally, I had to order the biggest pulley vortech makes to detune from 490!! So the big pulley and a rich tune holds her back for my stock block. Is this a bad idea? Can I just lean it out at idle/startup?

11.5 is not too rich under WOT. Ideally you want to know what you a/f is at startup and cold idle. Check you plugs and see if there are any signs of running rich on them. You may also want to for fuel leaks, possibly around the injector seals

starchman · Apr 27, 2005

Does it run OK once it has started, or do you need to keep your foot on the gas? If it runs fine, then it's probably not the IAC valve. When mine went bad I usually had to keep the throttle partially open (wide open when it REALLY needed to be replaced) for a while before it got warm enough to run normally. Of course, mine was nearly bone stock (K&N drop-in, silencer removed), so I didn't have any other possible issues like you have.

1of2000 · Apr 27, 2005

Yes, after I hold it to the floor it fires up and warms up fine. the surging idle doesn't start until its at operating temperature.

ps - 42# injectors, lightning MAF, 255lph intank & Trex ext.

1of2000 · Apr 27, 2005

jstreet0204 said:
11.5 is not too rich under WOT. Ideally you want to know what you a/f is at startup and cold idle. Check you plugs and see if there are any signs of running rich on them. You may also want to for fuel leaks, possibly around the injector seals

good idea, I will check the plugs... what color is rich?

jstreet0204 · Apr 27, 2005

1of2000 said:
good idea, I will check the plugs... what color is rich?

black. If it was runing right they should be a brownish color

1of2000 · Apr 28, 2005

Is this rich?

jstreet0204 said:
black. If it was runing right they should be a brownish color

Let me know if the attached pix look like its runnin RICH?!?!
FYI: They are Autolite 764 plugs, and they only have about 500 miles on them. So I am not sure if the white means HOT or NEW?

jstreet0204 · Apr 28, 2005

1of2000 said:
Let me know if the attached pix look like its runnin RICH?!?!
FYI: They are Autolite 764 plugs, and they only have about 500 miles on them. So I am not sure if the white means HOT or NEW?

From what I can see in the pics they look ok to me. Try this, try starting it without hold it to the floor, so that it doesn't start but turns over several times, then check one of the plugs to see if it is wet with gas. If not I would start checking fuel pressure during start up.

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