pulsing

[859tkw]

why does my car pulse when first started cold and does it bad until it warms up a little then smoothes out and runs fine. i have heard its because of the cam but is there any way to smooth it out some without the tune cause i can't afford that right now

[mustangkuhn90lx]

mine does the same once it warms up its better so hope people can shine some light on it

[859tkw]

yea its more annoying than anything lol when its down real cold it has to run for 15 min just to be able to drive it

[80 hate]

TPS senor is going out or needs adjusted.

[Kevin1989]

Mine is like that, but mine will shut off when its cold. And I know my tpms was right on. I just deal with it lol

[Kevin1989]

Tps* Damn phone

[2l8iwn]

could be a simple idle air bypass adjustment. Those things are known to get stuck as well. Some surge should be expected but i had a f cam on my 331 and it ran fairly smooth on cold starts with no tune.

[Adam@S&MMotorsports]

It's a 2 minute fix in the tune...

[2l8iwn]

but is there any way to smooth it out some without the tune cause i can't afford that right now:dummy: I think he was hoping a solution that didnt require him to pay for a professional tune.

[Adam@S&MMotorsports]

:dummy: I think he was hoping a solution that didnt require him to pay for a professional tune.

Usually tuning issues require a tune as the solution...:lol:

[2l8iwn]

I agree!! Definately the easiest way!! LOL

[859tkw]

oh i know i need a tune but i drive a dump truck hauling black top in summer and snow plowing in the winter therefore i have not worked since december. stupid mother nature screwed me. i plan on getting a tune within the next few months but was just hoping there was a way to calm it down for now! so yea u will be prob seein me in a couple months for a tune

[859tkw]

it pulses pretty bad and it almost undrivable for atleast five to ten minutes and have to babysit it to keep it from stalling it just sucks lol

[2l8iwn]

I would definately take a look at the idle air bypass valve. If it is not working or stuck it wont feed the engine when on the low side of the surge and it will die. where u located?

[sean]

where is the idle air bypass valve located and how do you adjust it? I have to two foot the car for the first 100 feet or so then it smoothes right out.

[Gearhead]

where is the idle air bypass valve located and how do you adjust it? I have to two foot the car for the first 100 feet or so then it smoothes right out.
You can't really adjust it, unless you buy an Idle air bypass plate, which is sort of a band aid, but it can smooth out your idle somewhat.

Circled in red:

[chris91]

Sean if you need to check it I have a spare IACV left over from my 91 you can use.

[sean]

maybe. I think i just need a tune. all i have to do it drive it for about 100 or so feet and its fine. Ill let you know though. thank you

[2l8iwn]

You can't really adjust it, unless you buy an Idle air bypass plate, which is sort of a band aid, but it can smooth out your idle somewhat.

Circled in red:

Gearhead is right you cant really adjust the iacv itself. What i was referring to is to start the car, unplug the iacv. Set the throttle body hard stop screw until the car reaches about 500 rpm. Then plug the iacv back in. The idle should jump up to about 850-900 rpm. Now depending how modded the car is that number may have to be increased. My 331 with an f cam i had to unplug the iac and increase to 700 rpm. Plugged the iacv back in and the car would idle smooth at 1000 rpm. Cold starts where really smooth doing it this way. GOOD LUCK!!