Any Help?

[Michael Dickerson]

I'm new here but not new to the internet so I've done quit a bit of searching already but can't really come up with a answer. I have a 95 Cobra and when I start it in the morning it will start and stumble and die and then fire right back up and goes to about 1500rpms and drops down to about 800 where it sounds like it has a cam(not sure if it does or not). When I take off sometimes it will cut out real fast and then be normal and a few seconds later the cel will come on and the car won't idle and seems like it's lost power. If I don't keep it running it will die but fires right back up. Ran the codes and it was code 158( maf got above 4.5 volts in the last 80 warm up cycles and code 556(primary fuel pump circuit failure). Sometimes the cel will go off and the car idles by itself and runs better but still doesn't seem right. Any ideas?

 

[madmustanger]

Madmustanger here: Mike jim vinson chester,sc I'm not a computer type guy might get someone with the tools and knowledge to check your electric circuits on fuel pump,ignition, and the computers in your particular model otherwise youcan put lota cash doing hunt n seek been there done that. I'm a carb guy don't like computerized equipment too expensive to fix n maintain mine's a 85 gt.
Getting a tech to check can pin point some of your problems such as bad fuel pump, shorts in the circuits of pump,ignition,distributor, regulator starter and computers. A plus is other guys here may be ableto help more but if nothing else my post could be a starting point gd k

 

[jrichker]

Fix the MAF code first. A junkyard MAF will cost between $20-$50. Do not swap the MAF sensor with just anything that happens to fit. The sensor and housing are not matched together to make a single part, but are designed to work together as a unit.

The table below lists the MAFs that are interchangeable with the 95 Cobra. Check the part number on he sensor to see that it matches the numbers given in the table.

MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.

When replacing any sensor, disconnect the battery negative terminal and turn on the headlights. This clears the computer memory of stored codes and settings. Turn the headlights off, reconnect the negative terminal. Drive the car for 15-30 minutes at highway speeds so that it van relearn the sensor settings.

After clearing the codes, recheck to see if the fuel pump code has gone away. If it hasn't or comes back replace the fuel pump relay.

 

[Michael Dickerson]

I cleared it and drove it then read the codes again and I believe the maf is bad. I got code 157 and 158 which are voltage to low and voltage to high in the maf. The fuel pump circuit failure also came back. I did the koer test and both sides were lean

 

[jrichker]

Fix the MAF problem first. That will probably fix any lean running issues you may have.