Rough idle gas burning smell please help!

SVTsamson22

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Recently bought a 2003 cobra with a 2.3 Whipple and I can't seem to find what's causing the rough idle and sometimes I get a burning smell it goes from 1000 rpms and drops to 500 to almost stalling any idea would be much appreciated.
 

DCguy

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Fuel rail pressure sensor, also known as the FRPS are common failures on these cars.....the sensor is located at the front of the driver's side fuel rail. When they fail they can allow excess fuel into the cylinders and cause a very rough idle and gasoline smell. I would also change your oil as its likely been saturated with gas.
 

SVTsamson22

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I just recently just changed my oil 3 days ago and changed my spark plugs along with a vacuum leak test would a faulty frp sensor show any codes because my check engine light hasn't popped up and would it be smart to check my egr sensor as well ?
 

hotcobra03

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The coils maybe getting weak,

These may not give a code until dead .

When I had issues I found a member close by who had a set of 8 to try first,

These aren't cheap to just throw in.

Side note,,
For me, any time I have issues running,
I do a basic compression test,

Drivers head has gotten me 3 times

Car will run ok on 7 cylinders with slight drive abilty issues
 

SVTsamson22

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So your saying a one of my coils might be out witch causes it to run on a Cylinder less ? Sometimes I start it up and runs fine then out of nowhere it starts idling rough I took to a dynotune guy to ask him and that's the day it ran like brand new we took down a back road with a sct tuner and I took down the numbers as he did some WOT and every number was in pretty good shape.
 

SVTsamson22

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I noticed when I changed the spark plugs one of them was pretty wet and would a bad gap cause a rough idle ?
 

SVTsamson22

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Lol I'm in my 20s and just now starting to learn things out in being my own mechanic and not paying someone to fix stuff after being ripped off many times that would take 1 min to fix I recently installed some spark plugs and a couple other little things and it felt damn good to do it yourself.
 

BlckBox04

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What type of throttle body do you have

try cleaning the mass air sensor also for another simple eliminator
 

ashleyroachclip

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Dis you check the oil , to see 8f it was thin and smelled like gas .
A ruptured fprs can load enough fuel to wash past the rings and into the crankcase .
This will cause the engine to run rich and poorly
 

SVTsamson22

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Picking up some maf cleaner and will check the oil it was recently changed this Monday if gas Is leaking thru I should still be able to smell it.
 

SVTsamson22

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Dis you check the oil , to see 8f it was thin and smelled like gas .
A ruptured fprs can load enough fuel to wash past the rings and into the crankcase .
This will cause the engine to run rich and poorly
Yes it smells like gas to me and is pretty clear what's my next move besides changing the oil ?
 

SVTsamson22

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Okay hopefully that fixes things I've been in a panic for the last week I've been worried the worst is going to happen the next time I WOT I'll be happy when it's running good again Thanks for the help.
 

SVTsamson22

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Changed the oil today and oil filter still idles rough is it possible by not having your spark plugs screwed in enough or not straight it could possibly cause theses problems I noticed while looking under the car my exhaust had some leaks in a couple areas I took a spark plug out and the tip was covered pretty good in oil idk what to do anymore this stuff is eating my pocket alive between taking it back and forth to ford and parts.
 

Roots-type

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It might help to see these suspect plugs. If it's covered in oil and has a bad gap (im assuming the ground strap is making contact with the electrode), it's probably not good. If the end of the plug has oil on it, and it's not leaking down the threads from the small cam cover donut gasket up top, then it's coming past a piston and or valve. If you can get a borescope that would be a quick way of checking on and eliminating/ discovering the piston as the cause.
 

SVTsamson22

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There was a plug I forgot to gap I had the rest set to 30 and the one with the most gap was set to 45 that one had oil at the end I'm taking it back to ford Friday so they can do a Inspection hopefully that should tell me after changing the plug the idle wasn't as bad but still getting some weird sounds from the exhaust and rich gas smell.
 

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