PDA

View Full Version : The Cobra is running TERRIBLE....HELP


White98SVT
03-02-2004, 11:14 PM
Well recently the Cobra has been acting up. It's a strange problem. Under full throttle load, and only in 2-5 gear at lower RPM's....it studders (sp?). It's running strong and if I gun it off the line from first gear it is fine. Or if I make a turn and nail it it's ok too. Any ideas?

I recently cleaned the IMRC's, changed the plugs, and changed the fuel filter and ran fuel system cleaner through it and nothing has changed.

The check engine light is on so I'm going to have the codes pulled tomorrow.

Firme
03-03-2004, 09:05 AM
sorry to hear about your troubles. The check engine light is your best lead. That should show you what the problem is.

Keep us posted.

venomous
03-03-2004, 12:55 PM
It sounds sorta like your mass air sensor is dirty. There is a wire (looks like a light bulb filament) in there that gets dirt and what not on it from the air filter. My Dad's 95 Gt showed the check engine light and was not getting hardly any power from 3500 on up. Once we cleaned the wire it felt like we had just put another motor in it. Or it could be like mine and the mass air sensor be dead. Maybe this is your problem too???

White98SVT
03-03-2004, 01:45 PM
Originally posted by Firme
sorry to hear about your troubles. The check engine light is your best lead. That should show you what the problem is.

Keep us posted.

Thanks man. Well I did get them pulled the other day before I tried to fix the problem and I got two codes. One was for the rear 02 sensor and one was "Misfiring on two or more cylinders"....so I'm off to see what else it is.

White98SVT
03-04-2004, 01:57 AM
Well here's the codes:

P0161 "Heater circuit malfunction bank 2 sensor 2"

P0156 "02 Sensor Bank 2 Sensor 2"

P0301 " Misfire Cylinder 1"

Could a wrongly gapped spark plug cause that bad of a stutter?

Also, could my Mil Eliminator be going bad? I just replaced the 02 sensor and put the Mil Elim. back on.

White98SVT
03-08-2004, 06:15 PM
Well after re-checking all the gaps on all plugs and re-wiring the Mil Elim....it's running worse than ever.

My question is this, every time I mess with the plugs it runs different. Could it be my crappy FMS plug wires? Or maybe the coil packs? Is there any way to test them?

Any and all help is appreciated.

tcrews
03-09-2004, 09:27 AM
Might be the wires.....my car had an intermittent studder that turned out to be bad wires. Sometimes it would miss, other times it was fine.

For the rear 02, sounds like you've got a bad Mil-eliminator. The mil-eliminator doesn't do anything with the signal coming from the sensor...it just sends an "all is well" type signal to the computer. If you are getting error codes from them then you are really getting an error code from the mil-eliminator. Also the rear O2 will not affect performance in anyway...functioning, malfunctioning, missing...doesn't matter. They will trip the check engine light but will not change the performance of you engine at all.

97CasperCobra
03-09-2004, 12:03 PM
Originally posted by tcrews
Also the rear O2 will not affect performance in anyway...functioning, malfunctioning, missing...doesn't matter. They will trip the check engine light but will not change the performance of you engine at all.

That's what I was thinking. Sorry to hear of the troubles Stephen. Find a buddy and see if you can swap out wires/coil packs with him, or drive down here and I'll let ya do it. :thumbsup:

Keep us updated man.

1-QIK-SNK
03-09-2004, 05:18 PM
I had a problem like that last fall. Tcrews told me to swap out my FMS wires and see what happens. So I put the stock ones back in and it has ran great since, so I think I would try different wires.

nckissfan
03-09-2004, 11:00 PM
I have had good luck with my MSD wires. My snake had the same thing, when one of the cylinders was missing. Summit Racing has these for $89 plus shipping.

BlownMystic
03-09-2004, 11:41 PM
i would go with Taylor 'spiro pro' 409 wires . they are on my car and it runs great..

White98SVT
03-10-2004, 12:07 AM
I had my dad overnight my stockers from home and I'm going to put them on tomorrow and see what happens.

I found a set of Excel wires for $70 plus shipping...anyone have experience with these?

smashedheadcat
03-10-2004, 11:23 AM
Originally posted by BlownMystic
i would go with Taylor 'spiro pro' 409 wires . they are on my car and it runs great..


I have these too. No expirience with them yet though. The look massive though. :)

White98SVT
03-10-2004, 07:08 PM
Well for those who said it may be plugs......you are RIGHT. I put the stockers on and it's running great.

Now I just have to decide on some new wires.....and then afford them:mad:

ausie
04-20-2004, 07:57 AM
This may not be of any help, but, I find my cobra runs better if I disconnect the battery for at least 1/2 hour when changing the plugs, and or air filter, etc.... First, check for codes before disconnecting the battery if you suspect there is a problem. I have found only two types of plugs that work well with my car, Ford Motorcraft (autolights are similar if not the same) and Denso Irridiums (there is a big difference with these plugs and is very noticable)
By disconnecting the battery for 1/2 hour allows for the computer to relearn the engine for compensation of the new parts. The timming advance and fuel delivery (fuel/air ratio) is adjusted. When changing plugs or air filter (etc) and not resetting the computer may cause the engine to run odd since the computer is still using old data. I would check the codes again even if the MIL is not on to see if there are any pending codes waiting. If the O2 sensors fail, one would think that the EGR system will operate in closed loop, and at the same time, the fuel/air mixture will be rich to prevent any detonation since the EGR system becomes inactive.
Perhaps the mis-fire cause the O2 sensor trip as well, sort of like a cascade fault.