Having serious prblems with my 03 cobra

[jetb306.erick]

I just got this car a about 5 months ago it has 55k miles on it with the following mods- ported blower, 2.93 pulley, long tubes, jlt cold air, and an sct tune. The car ran great till i overheated it twice and once i got that fixed it seemed to be fine. But now the car is having major problems pulling when i get to 3rd or 4th gear. When i get on the car in 1st and 2nd it seems fine just a little sluggish but when i hit 3rd it starts misfiring and backfiring about 4000rpms and if it makes it through 3rd it does the same in 4th and just doesnt want to pull. I put the sct tuner on it and it threw codes p0602 and p1000. If anyone has any suggestions on how to fix it please let me know. thanks

 

[wmburns]

The DCT P1000 simply means that all readiness tests have not completed. Have you disabled the rear O2 sensors in the tune? EGR?

The P0602 DTC suggest that the PCM flash memory has been corrupted. What happened before this DTC first showed up?

Suggest looking at the base engine and ignition. What are the results of a compression test? How much boost are you making? Spark plug gap?


>>
P0602 - Control Module Programming Error This Diagnostic Trouble Code (DTC) indicates programming error within Vehicle ID block (VID).

VID data corrupted by the scan tool during VID reprogramming

Using the scan tool, reprogram the VID block. If PCM does not allow reprogramming of the VID block, reflashing PCM will be required.

 

[hotcobra03]

cobra

what was the problem found that caused the car to over heat?

 

[jetb306.erick]

Kind of new to this tune stuff i have always dealt with foxbody 5.0s never really had a modular car, how would i disable the 02 sensors? And the car makes 17lbs of boost, and i just put a set of e3 spark plugs in it and i was told they are pre-gapped? I reprogrammed the car back to stock settings with the sct, should i clear the dtc's after i do this?

 

[jetb306.erick]

the overheating was caused by a leaking overflow tank, it had a crack in the welding.

 

[hotcobra03]

cobra

what else have you done to car that wasnt in 1st post

i have a predator and it says that code 602 can be normal as with po1000 as wm burns stated

are you sure about what mods have been done on car

 

[jetb306.erick]

the only things i can think of is it has both lower and upper pulleys, steig ported blower, 95mm mass air, jlt cai, bbk long tubes, magnaflow exhaust, 4.10 gears, larger radiator, 60lb injectors. I have heard something about these cars having 2 relays for the fuel, one for lower rpm and one for higher rpm?? it seems like a fuel issue cause that car idles fine and runs fine at lower rpms, but when you get on it like i said it starts backfiring at higher rpms and wants to stop pulling. But if you just ease into the throttle it will pull all the way through each gear, it only happens at WOT.

 

[Steve491]

I don't have a SC Cobra (wish I did) and I don't claim to be an expert by any means, BUT I don't believe you can put your car back to a factory tune with all the mods that you have.
Don't know if the 2003 has the same fuel pump relay as my 98 but it's fail safe. If the relay fails it runs the fuel pump in high gear. I think the blown Cobras have 2 fuel pumps..
Just my 2 cents.

 

[jetb306.erick]

i dont know for sure i just know the option is stock tune so i assume it erases the custom tune when you select it, but not sure. I think im just going to go have the car dynoed and tuned i have heard that could help? But i bought the car from florida and i live in alabama and i know the humidity and elevation levels can play a major role when tuning a car.

 

[Steve491]

My last post had an error. If the relay fails I don't know that it runs the pump at high speed, probably not. I do know that you can run the car without the relay in there. Sorry.

 

[wmburns]

FWIIW, For the DOHC 96-98 MY's uses a mechanical return based fuel system. The two speed FP ballast resister is wired across the relay contacts. When the relay is closed, the FP is in the high speed mode. When the relay is open, the power runs through the resister placing the FP into low speed mode.

Therefore, if the speed control fuel pump relay is removed, the FP will run in low speed mode.

The high speed mode is wired to the normally closed relay contacts. So it takes power to activate the low speed mode. Therefore, if the relay coil fails, the contact will remain in the high speed mode.

The 99-04 MY's use a RETURN-LESS fuel system. As such, they have a TOTALLY different system. The fuel pump driver module modifies the electrical duty cycle (power) to the fuel pump which makes the fuel pump speed variable and under direct control of the PCM.

 

[jetb306.erick]

i got the car fixed, all that was wrong with it was it blew the ends out of 4 plugs.. Now i got some ngk iridium plugs, do you know what i should gap them at

 

[BIGDATOWN]

Sounds like a really lean a/r if you blew the ends out of 4 plugs. A tune is very needed at this point do NOT try to stomp on it until it is tuned correctly!! or you will be buying another motor

 

[lightningbuff]

I agree with above post. Given your mods gap to about .032 to .034, tying to get as much gap as possible but test with tune or after. If your car hesitates with .034 the drop down and so on.

 

[jetb306.erick]

yeah i had too hot of plugs in the car, but i got it tuned with some cheaper ngk plugs and went and ordered the iridium plugs cause thats what the guy at the shop said to get. Thanks for the help everyone

 

[8.8mustang]

if you have not done this yet go get a cheap set of ngk v grove plugs and swap them had a similar problem and that was the fix. I am running one step colder then stock
ported eaton
2.7 pulley
fluid dyne heat exchanger
jlt cold air
dynomax 3' cat back
12.1 at 120.8 spinning on (street tires)