dannyscm

I have a mustang cobra 99 conv, and lately I’m having problems when the car exceeds 5000rpm. Check engine light is off and I have a superchip install with flow master x pipe and no catalytic converters. I have 02 bi-pass sensors to get away with the check engine light. I was thinking the supership was the reason of failure, so I changed the computer settings to stock. The problem got worst, so I had to leave the superchips tuning installed. Now, a friend of mine told me that it could be the fuel filter. I replaced the fuel filter but the problem is still there. When the car is steady and shift gear at Neutral the rpmīs go until 7000rpm. As soon as I shift 1st gear, then the RPMīs stopped at 4500-5000 rpm. I already checked coils, spark plugs. It feels like there is a lack of fuel or current. I went to AutoZone, and they scanned the car with their computer, and they said there was no problem. At this point, I’m thinking it may be the fuel pump, but I’m not sure. Any help will be appreciated. Another thing is that something is draining my battery. If I don’t turn the car on every 2 days, then I run off battery. I’m thinking it may be the alternator that is acting up. One more thing, what is the regular pressure for a stock fuel pump?. I check the pressure and it was 32. Please let me know.


Sincerely

Dannyscm
Mustang cobra 99 vet

Black*Death

My Chilton's lists Cobra's fuel pressure at 30 to 55 psi at idle.

Chilton's is obviously not the best source but I think it should be very close.

Black*Death

Battery may be bad Alternator. If RPM's are shooting up at idle(is that what you are describing?) then may be IAC. It is attatched to side of throttle body. It is used to control airflow at idle when TB is closed. They do "wear" out or may need to be cleaned. Not really sure what problem you are describing. Is this happening during driving or simple when you are at idle and rev the RPM's??

cobraetti

definatly check the IAC valve(or clean), what kind of superchips handheld or chip @ the ecm?

dannyscm

Yeap, Itīs at idle. when Iīm driving and doing high RPM started to shoot up at 4500-5000RPM. I did what you told me to do. Cleaned IAC and car is doing better, but still the problem is there. I guess that I have to buy a new IAC valve and try one more time. Iīm hoping the fuel pump is good. Thank you for your quick reply. It happens when driving most likely.


dannyscm

dannyscm

Thank you for your quick reply. I think I have to buy a new one. I cleaned the valve and the car is working better, but still the problem is there. I hope the fuel pump is not the problem.


Thank you.

dannyscm

dannyscm

I replaced valve IAC and did not fix the problem. I had to replaced the fuel pump as I said, now the car is working the way is supposed to. I bought the factory fuel pump (Motorcraft) and replaced fuel pump filters. There was mud inside gas tank. The car is doing almost 7000RPM with no problems.. Finally.....

cobraetti

mud in the tank?, how

are you using the superchips handheld tuner?