1995 Cobra Rebuilt motor, number 3 and 4 not firing.
my buddy has a 1995 cobra with the 5.0 motor. the rebuilt motor has only 280 miles on it. its running aweful. the number 3 and 4 is not firing at all. what could have caused this. praying its not a burnt valve. its like its skipping and everything else. any info is greatly appreciated. thanks
Last edited by johnc_95gt; 09-27-2009 at 02:00 PM.
Reason: didnt say that it was rebuilt motor
my buddy has a 1995 cobra with the 5.0 motor. the rebuilt motor has only 280 miles on it. its running aweful. the number 3 and 4 is not firing at all. what could have caused this. praying its not a burnt valve. its like its skipping and everything else. any info is greatly appreciated. thanks
i would check dis cap and rotor first? be sure that all plug wires are in the right firing order
and i would check the timing as well
we have found out today the guy that he just got the cobra from has the o2 censers crossed up. thats also the code it gave us. bank 1 and bank 2.. so we contacted the last owner and he said he thinks he may have crossed these to up. would thinks make any difference... any info greatly appreciated.. thanks
i would check dis cap and rotor first? be sure that all plug wires are in the right firing order
and i would check the timing as well
Good suggestions!
Quote:
Originally Posted by johnc_95gt
my buddy has a 1995 cobra with the 5.0 motor. the rebuilt motor has only 280 miles on it. its running aweful. the number 3 and 4 is not firing at all. what could have caused this. praying its not a burnt valve. its like its skipping and everything else. any info is greatly appreciated. thanks
I'm guessing when you rebuilt the motor that you put in all new ignition parts including distributor, cap & rotor, plugs, wires, etc.?
It could be the distributor going bad, bad plugs, bad fuel filter/pump. There are a number of things that could be wrong.
Quote:
Originally Posted by johnc_95gt
we have found out today the guy that he just got the cobra from has the o2 censers crossed up. thats also the code it gave us. bank 1 and bank 2.. so we contacted the last owner and he said he thinks he may have crossed these to up. would thinks make any difference... any info greatly appreciated.. thanks
How can you "cross" the O2 sensors??? That doesn't really make much sense. So I HIGHLY doubt that is a problem.
Although you MIGHT have bad O2 sensors, which can make the car run crappy.
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i didnt rebuild the engine, new msd distributor, and ford racing wires and some high dollar plugs, not sure what plugs are called this is a friends car. The o2 sensor deal was said from the previous owner. He stating that all that needs done is the ecu needs to be reset and tuned. It had huge horsepower with nos before the engine was rebuilt. since its almost back to stock would computer need to be reset? im not fimiliar with any of it im going by what the previous owner is stating ya know. hard to tell because i dont think he knows. lol
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1995 Mustang GTS 5.0
Cold Air Intake
Pro 5 Short Shifter
Flowmaster Exhaust
H-pipe 3 inch pipes 4:10 Gears
Try swapping those fuel injectors to different cylinders to see if it follows. I have had those not spray after doing a rebuild. It is a real pain to track them down.
i didnt rebuild the engine, new msd distributor, and ford racing wires and some high dollar plugs, not sure what plugs are called this is a friends car. The o2 sensor deal was said from the previous owner. He stating that all that needs done is the ecu needs to be reset and tuned. It had huge horsepower with nos before the engine was rebuilt. since its almost back to stock would computer need to be reset? im not fimiliar with any of it im going by what the previous owner is stating ya know. hard to tell because i dont think he knows. lol
If he was running NOS there is probably a tuning chip in the PCM J3 port. If the engine is now back to stock I would remove the chip and let the PCM control all the functions as it was intended. Since there are only 2 (left and right) O2 sensors there is nothing to be crossed.
now were talking bussiness, would that chip be located on passenger side where the superchips go? Behind the panel? ill get him to check, if there is no chip what then? would he still need to reset the computer somehow. thats what the guy keeps telling him all it needs is for the ECU to be reset or tuned or something, dont know anything about the ecu but would that need to be done and where would i find for him to do that at in north east georgia?
__________________
1995 Mustang GTS 5.0
Cold Air Intake
Pro 5 Short Shifter
Flowmaster Exhaust
H-pipe 3 inch pipes 4:10 Gears
now were talking bussiness, would that chip be located on passenger side where the superchips go? Behind the panel? ill get him to check, if there is no chip what then? would he still need to reset the computer somehow. thats what the guy keeps telling him all it needs is for the ECU to be reset or tuned or something, dont know anything about the ecu but would that need to be done and where would i find for him to do that at in north east georgia?
The ECU is located behind the passenger side kick panel. If there is a chip installed it will be obvious as it's plugged into the J3 port (only one). To reset any existing fault codes disconnect the negative terminal at the battery for 15+ minutes. These computers have adaptive strategies so it will effectively (re)learn from the various inputs. The ECU itself cannot be tuned directly, that's why tuning chips are added if the mods require new operating parameters.
1995 Cobra Rebuilt motor, number 3 and 4 not firing. 
That doesn't really make much sense. So I HIGHLY doubt that is a problem. 
