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03 cobra boost issues

3K views 12 replies 9 participants last post by  DuffManRHA 
#1 ·
Hey guys what's up..having some issues with my 03 cobra and wanna hear what you fellas have to say. I made two different posts over on svtp with no luck so..long story short...I bought the car a few years ago all stock. I then sold it to a buddy of mine and within 2 days he ripped the clutch completely out of it. He had no where to store it and didn't seem to be in any hurry to fix it so it sat under my carport for almost a year n half. Finally I talked him into selling it back to me. I put a new clutch in it along with a fresh oil change, fresh synchromesh in the trans and new gear oil in the rearend. Anyways I fire it up and it runs kinda rough at idle so I figured probably just old fuel. I take it for a little ride and notice it's not building boost so I assume it's in limp mode. I add some fresh fuel with some seafoam and it idled much better but not 100% but still having the boost issue. No check engine light so I never put the scanner on it. With no help over on svtp I decided to do the boost bypass mod(at this point I was willing to try anything)and the idle seemed to get even better and now when I drive it the boost gauge shows boost but there is no seat of the pants boost if that makes sense. I'm afraid to keep running it like that because it's probably detonating at WOT. Today I put a scanner on it with no check engine light and I got a po306 meaning #6 misfire..I checked all the plugs on the drivers side and all looked good so I got a new COP and put on #6 cylinder and the idle seems to be 100% now but when I jump on it, the boost gauge works as it should going up to 7ish lbs of boost but feels like I'm driving a na 4 valve with no boost..still no seat of the pants feeling..idk what else to do. There is probably still some old fuel in the tank but I'm not sure if that's causing my problems..any help would be greatly appreciated..thanks
 
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#2 ·
If it has bad gas the computer is gonna retared the timing to keep it from detonating and this will cost u a lot of power. Run some cleaner through the gas and run atleast a full tank of 93 or more before u start getting on it. If u take a boosted car that has sat for along time and start beating on it not knowing if the gas is bad or if there could be other problems then u are asking for problems. Take the time to let all the bad gas burn out and let everything get clean and lubed and warmed upand use to running again . Take your time
 
#5 ·
I think you misunderstood what I asked. I asked if there was a sensor, likely in the fuel rail or tank, that detects bad gas. I've never seen one but I do learn something new every day. Your smart as response was definitely not needed and not productive for the whole of the forum.
 
#8 ·
Don't let that gas run through the engine! The best thing, and it is a PITA, is to drop the tank and drain it or drop it enough to stick a hose in the side of the filler neck gasket on teh side of the tank and siphon it all out. It will clog up the fuel filter (not a big deal) as well as your fuel injectors (big deal) and foul plugs, it's just nasty stuff. Once you've done that, changed fluids, put new plugs in with correct gap, etc. go for it again.

In the future if you store a car, pour some Stabil in beforehand and it will preserve the gas and you can run that through your engine instead of draining it, but you also want to store with hardly any gas. Then when you drive it again you put a lot of fresh gas in, thereby diluting the Stabil-laced gas even further.
 
#11 ·
Sounds like a lean issue caused by fuel starvation.
 
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