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1993 Taurus Running very rough after tune-up


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Bunny161
New User

Aug 22, 2011, 4:17 PM

Post #1 of 14 (3546 views)
1993 Taurus Running very rough after tune-up Sign In

1993 Ford Taurus, 3.8L 6cyl FI
Did tune-up & checked plugs - back 3 plugs were soaked in gas. Replaced plugs & it ran good for an hour or so and then started missing. Auto parts guys had me replace the fuel pressure regulator. After this the engine started missing very badly at stop signs and lights & has died there a few times. Got diagnostic ran. The guy said I needed ERG vacuum solenoid, oxygen sensor, fuel filter, & maybe fuel pump. Sounds to me like he just wants lots of $$$$ - which he won't get 'cause I'll do it myself - but do I really need all these parts replaced?Crazy


Discretesignals
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Aug 22, 2011, 5:33 PM

Post #2 of 14 (3519 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

You might not need all those parts replaced, but it is really hard to say unless you provide some sort of diagnostic test results or data from those systems to determine if they are indeed in need of replacing.

Why should the fuel pump be replaced? Is the fuel pressure or volume to low? Is the pump noiser than usual? Does the pump not operate at times?

What is wrong with the EGR vacuum regulator? Is the regulator not opening to allow vaccum to the EGR valve or is the valve stuck open and allowing EGR flow to occur all the time?

Why does the O2 sensor need to be replaced? Is it sticking, has a slow response to lean and rich conditions, or is the heater bad inside it? If the engine is running rich to begin with, that needs to be solved first or your replacement O2 sensor will be fouled out.

Is the fuel filter plugged up? If they are wanting to replace the fuel pump for some reason it usually is a good idea to replace the fuel filter also.

As you can see there are a lot of questions that need to be answered and data provided to determine if those parts are indeed in need of replacing or not.





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zmame
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Aug 22, 2011, 5:36 PM

Post #3 of 14 (3517 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

Hard to say if you do or you dont.. did these problems happen right after you did the tune up? or was the problem there from the start.
If yes
-check cap and rotor for miss aligned install/loose/damage
-wires that have come off/damaged

If you pull the vacuum line off EGR dose it run smoothly?
Whats your Fuel pressure reading key on engine running?
After you get it running better you can diag the O2 sensor.


zmame
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Aug 22, 2011, 5:37 PM

Post #4 of 14 (3516 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

beat me to it lol.


Discretesignals
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Aug 22, 2011, 5:58 PM

Post #5 of 14 (3510 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

More info is better than no info. Smile





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Bunny161
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Aug 23, 2011, 1:06 AM

Post #6 of 14 (3491 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

A mechanic at a shop did the test and I never saw any of the results! All he told me was the list of parts he said I needed and the bundle of $ he wanted to do all the work.
The fuel pump runs after vehicle is shut off and always has strong odor of gas when driving or just after shut down.
I simply thought the fuel filter might be part or all of the problem and it is the cheapest to replace first.
zmame told me to pull off vacuum line on ERG to check so I will try that in the morning.
If you have any other suggestions, I would love to hear them.
Thank you guys for your responses.Laugh
Bunny161


zmame
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Aug 23, 2011, 4:27 AM

Post #7 of 14 (3482 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

Usally if you can smell fuel, it means fuel is leaking somewhere. I would check the rubber flex lines that connect the 2 halfs of the fuel rail common area.


(This post was edited by zmame on Aug 23, 2011, 4:28 AM)


Bunny161
New User

Aug 23, 2011, 5:02 AM

Post #8 of 14 (3473 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

Thanks Zmame, I'll do that. Do you know anything about a "smoke test" to pinpoint gas leaks? I saw that on a different post but I have no clue about it - got any ideas? What kind of smoke would you use that wouldn't blow up?
Bunny161


Hammer Time
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Aug 23, 2011, 5:15 AM

Post #9 of 14 (3471 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

That's not for finding gas leaks. It's for finding air and vacuum leaks.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
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Aug 23, 2011, 3:40 PM

Post #10 of 14 (3452 views)
Re: 1993 Taurus Running very rough after tune-up Sign In


Quote
The fuel pump runs after vehicle is shut off


Finding the fuel leak is important, but figuring out why the fuel pump is staying on after the engine is shut off would be the first area to begin diagnosis after determining and repairing the leak.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Aug 23, 2011, 3:53 PM)


Bunny161
New User

Aug 23, 2011, 10:53 PM

Post #11 of 14 (3433 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

Good idea. How would one go about doing a diagnosis for the fuel pump? I know I probably sound like a dummy but I can't figure it out if I don't ask!
Bunny161


Discretesignals
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Aug 24, 2011, 4:51 AM

Post #12 of 14 (3427 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

Well, the pump is running, so that is a good sign. The question is does the fuel pump run continuously with the ignition turned on with the engine off?





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mar15252
New User

Aug 24, 2011, 11:05 AM

Post #13 of 14 (3415 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

hi, bunny is working on my car. the fuel pump usually only makes noise when it's a very hot day and it will run for about two minutes after i turn the car off, but i have the gas smell all the time i drive it. this has been happening for many years now. on the freeway i get 24 mpg, in town i get 10. when she did the tune up, the back 3 plugs were soaked in gas, the rotor and the distributor cap were extremely worn, i have no idea how it was running but it ran good. after the plugs, cap and rotor were replaced it ran bad. at a stop sign it runs real rough, stalled twice, but seems to run good at 35mph, at 45mph it coughs once in awhile. i got a free diagnostic test and that's when they said i needed the sensors and my check engine light has been coming on and off for 2 years. we didn't replace the wires or the fuel filter. thanks so much for all your help


Discretesignals
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Aug 25, 2011, 7:51 AM

Post #14 of 14 (3381 views)
Re: 1993 Taurus Running very rough after tune-up Sign In

First place you should start is to figure out why the fuel pump is running with the engine turned off. The fuel pump shouldn't be running for 2 minutes after the engine is shut down. The engine computer (PCM) communicates with a constant control relay module (CCRM). The CCRM houses the fuel pump, fan, and WOT relays. You need to figure out if the CCRM or the PCM is keeping the fuel pump relay enabled. The PCM grounds the primary coil circuit in the fuel pump relay to energize the relay and turn on the fuel pump.

To check this you need to back probe the CCRM connector on the light blue with orange striped wire pin 18 and check for ground from the PCM when the problem is occurring. If you see a ground, replace the PCM. If you don't see a ground, more than likely the CCRM is the fault.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Aug 25, 2011, 8:05 AM)






 
 
 






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