greengt03

I am new to this forum, and want to say thanks for any help I can get on my 03 GT. Sorry if this is kind of long, but want to present the issues I have encountered so far.

Bought an unmodded 03 Mustang GT w/5 speed last year from the original owner w/69k miles on it, and it is super clean and nice. Car ran great, I put it in winter storage, filled the tank with non ethanol premium fuel and added stabilizer. Went to get the car out for spring, battery was a little low so I had to put on the charger to start it. Car started fine and I let it warm up to temp, and went to drive it and it sputtered and died. Went to restart it, and it would crank over but no sign of wanting to start. Waited awhile, and got it restarted ok, but I was letting it idle, and it would idle real smooth, then it make a gurgle sound around the air box, idle would drop and run a little rough, then pick up and idle smooth again. Would do this over and over again. I would blip the throttle and it would rev up, but would stumble and then died. Would not restart. Took off battery cables, recharged battery, put cables back on, and it restarted. Same thing, would idle smooth, make the gurgle sound, idle drop run rough, then idle would pick again. I shut it off, and I tried to restart it, and again it would not start(no sign of wanting to fire). Again took off cables, checked voltage of battery 12.7 volts, put cables back on, and it started, but when it did it threw 2 cel codes of p0172 and p0175 (too rich bank 1 and too rich bank 2. I shut if off, and tried to restart it, and again a no start. Any ideas on what the heck is going on. It ran like a top when I had last driven it, but now it is really acting weird.

Upon some suggestions from others, thought the MAF might be dirty to cause the cel codes. Well, I took out the maf sensor, no real debris on it but cleaned it with CRC MAF sensor cleaner, and took out the K&N filter, but all looked good with no obstruction or anything out of the ordinary. Put all back together, but again it is a crank with no hint of a start. Yesterday it started and ran, but today no dice.

The things I do notice, is I do not hear the fuel pump cycle when ignition is turned on, and when the ignition is on the theft light stays on for a couple of seconds and then goes out as normal, but when trying to start stays on while cranking. It did not do this yesterday. Again it is strange, but I will keep chipping away at a cause.

I am leaning towards a bad fuel pump, but some of the other symptoms I have experienced I am not really sure. Tonight I am going to try spraying starter fluid into throttle body to see if I can get at least a hint of a start. If anyone has any suggestions, I am all ears!! Thanks again.

cliffyk

Check the battery voltage while cranking the engine--it should be 10.5 V or more, if not the battery has a dying cell-one that can deliver its 2.1 V under under no load, but falls off rapidly under the starter's load...

greengt03

Last night was able to remove the throttle body intake tube and give it couple of shots of throttle body cleaner and was able to get it to fire up for a short period. Repeated this several times with the same results. Looks like it is possibly the fuel pump now at this point. Figures, I have a full tank of fuel, now will have to drain it. Thanks.

JeffBall

Before id replace the fuel pump, id check the fuel filter.... could have had some ethanol fuel in the filter gum up while it was sitting.

Shampue

Could this be caused by a faulty the Idle Air Control Valve? I had idle issues with my 2001 GT and that fixed it. The IAC value for my 01 was $50. I think the 03's use a slightly different one that is about $85.

greengt03

Thanks for the responses! At this point, It will no longer start, and I do not hear the fuel pump kick on when I turn the key on. It will fire and run momentarily with a shot of TB cleaner into the intake. If the fuel filter is gummed up, shouldn't I still hear the fuel pump kick on? I don't fully know if the fuel pump could have caused some of the other odd idle issues I have seen, but right now I am leaning towards the pump. The issue I now have, is how can I drain the full fuel tank I no have. From what I have read so far, there is not a good way to remove the fuel, so I can drop the tank. I am open for any ways to try and get some of this fuel out of the tank. I will be doing this by myself, so trying to drop a full tank does not look like an easy task for a single person.

greengt03

OK, had not had a chance to do anything on the Mustang for a couple of weeks, and was resigned it is the fuel pump, but charged up its battery tried to start it, and it fired right up, idled ok for about a minute, but then the idle started fluctuating up and down again and it would act like it was going to die, and then regain the idle again. It would again stumble bad on trying to blip the throttle. Shut it off, and no restart again. Waited a few minutes and it did restart, but had terrible rough idle, and it would fluctuate up and down again. I really can't hear the fuel pump kick on, but it did start up a couple of times after I tried listening for it.

Can a bad MAF sensor cause a no start, then start and run rough with erratic idle? I am searching here, and really do not want to drop the tank if I don't have to. Any tests out there for the sensors that might lead me into finding the issues with this car. I have been an old school car hobbyist (pre 1973) models for 45 years and not the best with newer equipment with all the different sensors and their roles in having a car run right. Thanks for any help..

JC316

To rule out the MAF, just unplug it. It will idle like crap, but you should be able to keep it running. Only other sensor that can cause a problem like this is the crankshaft position sensor or camshaft position sensor going bad.

You really need to check your fuel pressure. It could be the fuel pump driver module going bad, or even the fuel pressure regulator. This video is what happened to me when the FPDM was just starting to go out. When cold, it would have strong fuel pressure, but once it would warm up, the fuel pressure would start dancing and the car would misfire like all hell while driving.

stangsx3

Hey Ive got the same situation.Funny the last two years when it got warmer over 65 degrees or so it ran great untill the weather was cold again in fall. I store it and the same thing this year. It wouldnt start the last few days untill it got warm today but this year idle worse, misses when push gas, wont rev high and all your stuff too but wont stay running over ten minutes also idle will be great for a few then stall,,, i have to wait awhile and it may or may not start again. Please what did you find?
stang838

greengt03

OK, here is the result of situation with my problems with my Mustang. It would start at times, and run for a while, start to miss and then die. And not start again. It started throwing some codes like p0190, p1132, p1152. Never could hear the fuel pump prime when the key was turned on. I tried a MAF sensor, and a fuel pressure sensor with no luck. Finally replaced the fuel pump and that was the answer to all the strange problems and codes. Car now runs perfect and this was the answer to all the problems. My biggest problems was my car had a full tank of gas, and no way to siphon out the fuel and no way to do this myself. I towed the car to a local trustworthy shop I know and had the fuel pump replaced with only 200.00 in labor to do the job. I had the pump already, so I feel this was a great deal. So now is all and well.