Mechanics

TAURUS //FIRST START OF THE DAY PROBLEM

1999 Ford F-150

: ( Ok here I go,
1999 Ford Taurus 133K miles. A month ago we brought the auto in because of first start problems. More specifically, it cranks fine but takes any where from 1 to 7 tries to get it to finally stay running. I replaced the alternator before this because the batt light had come on indicating no charge and before that the check eng light came on with and EGR code and I replaced that.
$1,150 poorer & after two different repair places the car exhibits the same first start difficulties. They both have indicated frustration but used my $ to experiment through the diagnosis process.
Here is what has been repaired and checked:
[u: 2e72784d6f]1st Mechanic[/u: 2e72784d6f]
Fuel pressure at the rail both running and not: good(45psi)(bleed off pressure stabilized @ 25psi)
Injectors: good
Spark plugs replaced: good
Spark: good
Mass Airflow sensor: good
EGR: replaced
o2 sensors: good
Computer: check/good no codes starting/running/off
EGR Differencial Pressure Switch: replaced
EGR Control Solenoid: replaced
Coil Pack: replaced(#2 was bad)
Plug Wire Set: replaced
Air Filter: replaced
[u: 2e72784d6f]2nd Mechanic[/u: 2e72784d6f]
EGR/Induction Flush
Flush Injectors
Mechanic said he sprayed gas in the intake and it fired right up but only did that once, don't know after that.
The problem was put over the internet to all the mechanics but no one came back with a fix

Outside temp does not seem to matter when it comes to starting. It took me 3 tries to get it started when I picked it up and subsequently the last two days 7 & 5 tries. Like I said the engine cranks fine, no codes. Once it starts for the first time and there after it runs perfectly and starts up without any problems.
Frustrated and poorer looking for help.
Avatar
Capt1857
December 8, 2006.



It looks as if you have done an almost thorough search for this problem. One more thing you may want to check out is the engine coolant temperature sensor. This sensor detects the temperature of the engine and adjusts a voltage signal to the cars computer. The computer then takes this value and adjusts the air fuel mixture accordingly. There is a way to test the values of this sensor but I don't have it for your particular vehicle. There are a few sensors that help the computer determine the air fuel mixture for the car ie: mass air flow, o2, and the ect (engine coolaant). However since the problem only exists when the vehicle is cold it would lead me to beleive that it is the engine coolant sensor. If you want to make sure, find out what the resistance for that sensor should be and test it before replacing. Hope this helps. Good Luck : )

Tiny
Backyardmechanic
Dec 8, 2006.
One more thing you may want to check out is the engine coolant temperature sensor. This sensor detects the temperature of the engine and adjusts a voltage signal to the cars computer. The computer then takes this value and adjusts the air fuel mixture accordingly. There is a way to test the values of this sensor but I don't have it for your particular vehicle. There are a few sensors that help the computer determine the air fuel mixture for the car ie: mass air flow, o2, and the ect (engine coolaant). However since the problem only exists when the vehicle is cold it would lead me to beleive that it is the engine coolant sensor. If you want to make sure, find out what the resistance for that sensor should be and test it before replacing.

The ect, great. Would the value of the signal being sent from the ect change immediately after the first start? Once I am able to get it stated for the first time I turn off the eng and then immediatley try a restart and it fires up without any problem.

Tiny
Capt1857
Dec 10, 2006.
This is tough to answer. For how long do you run the car before trying to restart it? The ect responds (or is supposed to) to any temperature difference. The change in temperature difference will change the signal to the PCM.

Tiny
Backyardmechanic
Dec 10, 2006.
I have tried the restart immediately after it starts for the first time. Can't be anymore than 10sec's or so.

Tiny
Capt1857
Dec 10, 2006.
I suggest that you test the engine coolant sensor with the car cold and record it's reading. Then start the car for 10 seconds and shut it down. Again with an OHM meter test it and record it's reading. If there is a drastic difference in readings I would suspect that the ECS is still bad. However the right way would be and to be absolutly certain is to get the resistance specs for that vehicle and that sensor and compare to the readings that you are getting.

Tiny
Backyardmechanic
Dec 10, 2006.