[O-NoA5-O]

OK. So I replaced a fuel pump and the fuel pump relay. When I start my car it will idle for a second then die. It usually takes about 10 seconds to start back up again. If I start it and push the gas and hold it around 1000 rpm's for a minute or so, then it will run fine but idle up and down 500 rpm or so at idle. Any ideas on what may cause this?

 

[GhostDog 5.0]

Have you tried adjusting the idle screw at all? Clean the idle air control valve? Verified the TPS voltage?

 

[O-NoA5-O]

I have no idea how to do any of that. can you fill me in? I did notice a vacuum line that is broke on the back of the throttle body and runs over to the passenger side firewall. it's a white line. ???

 

[cfiiman]

I can't remember what the white line is from but the place it runs over to the passanger's side is a vacuum harness...I know this because when I installed my s/c I broke every damn line on that harness b/c of how old/brittle they were...You can no longer get that harness from Ford as it was discontinued in 2000 I believe...I fixed it by cutting off the harness and just running vacuum line to and from the plastic lines in the engine...I haven't figured out a better way to do it yet...You could do that to your white line and see if it helps the situation at all...I think maybe that line you are discribing is to the EGR valve not the TB...
Jason

 

[O-NoA5-O]

yeah it runs to some sort of contraption that's attached near the TB. I'll run some line and see if that helps. Thanks for the info!

 

[Black06]

It sounds like you have a major vacuum leak.

 

[O-NoA5-O]

uh oh! i did tear the dash out and put in a new heater core but i only seen three vacuum lines and one through the firewall and 2 more to the heat & a/c controls inside the car. i think. other than that the only one that i can see that's broke is the white one that i mentioned earlier. would the heater & a/c vacuum lines have anything to do with the idle and the car dying after i start it?

 

[GhostDog 5.0]

The only vacuum that has to deal with the heater/a/c is the black vacuum line that goes through the firewall into the dash.

Make sure you repair all of the broken vacuum hoses. Part stores sell them and cut them to length.

Here I described setting your throttle position sensor in detail.
http://www.allfordmustangs.com/forums/showthread.php?t=32799

To clean the idle air control valve you just unclip the harness, remove the two bolts and spray some carb cleaner in there and try to move the valve up and down some to get the crud broken free. Spray it a little bit more. Be sure to put the electronic side up so fluid wont run into there.

 

[1stPny]

The white vacuum line you are talking about is your EGR line. I know. i broke mine. :worship

You can either replace it with the equilvalent or just leave it off. i did. But I also do not have the same problems that you have.


Sounds to me like you need to clean your IAC or replace it.

 

[O-NoA5-O]

ok....i checked everything ghostdog said....I set my idle, got my TPS voltage to .85 and i still have the problem.....any other suggestions?

 

[meangreen92]

How's your cap, rotor, wires, and plugs?

 

[89GT5liter]

check your 02 sensor voltage, this can cause a fuel mixture problem

 

[O-NoA5-O]

check your 02 sensor voltage, this can cause a fuel mixture problem

How do I check the O2 sensor voltage?