After years of reading this forum and occasionally providing answers for folks, I find that I need some help. My 2005 GT with 90K miles (I bought it new but I drive a lot) refused to run yesterday completely out of the blue. Got home from work the night before, parked in my garage as always, and next morning it started and ran rough for about 20 seconds, then died. Since then, it will restart, run extremely roughly for a few seconds, then die. No matter what I do with the throttle I can't get it to stay running more than 5 seconds, but it will immediately restart and do the same thing, up to the point that it gets flooded or the battery goes dead. It has 90K miles, a JLT cold air kit and Doug Bama tune that I installed a couple years ago, and there is about 4 gallons of Chevron gas in the tank. I haven't yet changed the plugs, but up to this point it was still running perfectly so I doubt that enough of the plugs fouled simultaneously to cause this problem. I changed the fuel filter, cleaned the throttle body, examined the MAF for oil buildup from my cone type air filter, and everything appears fine, yet it won't run more than a few seconds. My SCT tuner shows no codes, and I can hear the fuel pump pressurize the fuel system when I turn the key on. At this point I don't know what to do. Since it will repeatedly start, it has spark and it has fuel. To my thinking, it couldn't plug enough injectors nor foul enough plugs to make it stop running, considering that it was running perfectly up to that point. I would like to check the fuel pump output, but I don't know how to do it on the returnless fuel system. The only other clue I can offer is that before yesterday, there were perhaps 5 times since new that it has started and run roughly for 10 seconds or so, and then it clears itself out and runs fine. The last time it did this was only a few days ago, but again it ran roughly for maybe 10 seconds and then it was fine. Also, my car, like many other 3V's, has always burned very blue smoke if it was started, left to run for only 30 seconds or so, shut back off, and then let sit for an hour or more. After sitting like this, then the next start will always be very smokey with blue smoke. I appreciate any ideas or diagnostic assistance you can give. I'm an okay mechanic but not a very good diagnostician, so I need your ideas, especially any Ford techs out there. Thanks a lot in advance, Owner1
Wow, sorry to hear that. This is just a shot in the dark, but have you ever had the leaking problem on the passenger side that could have fried something in the computer? The fact that no codes are thrown leads me to a problem with the computer in the car. Again, I'm just guessing.
help you have a tuner,,hook it up and with datalogging option you can read your sensors with key on engine off..search some of the posts with pats problems...you will find problems with the tps1 and tps2....and some ground problems with the new style car
tuner example,when i look at my tps volts it reads .99volts and press gas to floor and volts go to 5.0 so then it tells me its working...you will need a referance chart to know what readings should be.. i have one for a stock 03 ...if you need
I dunno what to tell you. My guesses would be fouled plugs, fouled injectors, or a blown gasket, none of which sound obvious. My first guess would have been bad MAF, but you said you inspected it and it looks fine. Dan
My BMW did that and it was the Mass Airflow sensor. I'd check the connection and any data you can get from the SCT on that item. Did you recently re-oil your CAI? If so, that can foul the MAF sensor (the filter oil can contaminate the sensor).
Crank Sensor??? They like going on cars when they near 100k Sounds like the car runs about 5 seconds because the fuel gets dumped and sparks are made....but then the computer has no way of knowing what the timing is to keep it running. Just a random guess based on what ive seen on many ford vehicles 4.6 /5.0 Ford seems have ignition modules/ crank sensors that don't like living over 100k. ~Chris
I'm stumped myself but I think its something mechanical being there are no codes, def check fuel pump pressure, any air leaks from the CAI, battery voltage. For ****s and giggles, load up factory tune and see what happens, I've experienced this before in a couple of cars ...almost like a "brain fart", if it runs on factory tune then reload the performance one.
Ditto Exactly the same thing that I was going to suggest, "Upload the Stock Settings and see if the problem goes away". If that doesn't work, then I would start looking into the Fuel System. I guess I haven't paid enough attention to my 05, but you're saying that there isn't a port on the fuel line in the engine bay that you could hook-up a gauge to check your fuel pressure.
When is the last time you changed the fuel filter? Supposedly those need to be changed fairly often. Dan
Thanks for ideas--I'll try some tonight Thanks everyone for the ideas you've put forth. I'll try some of them out tonight. If anyone else has any ideas, please put them out there too. A failed crank sensor does seem like it could cause the things I'm seeing. BTW, I changed the fuel filter right after the car refused to run. Thanks to everyone so far, I'll let you know how it goes. Owner1
i'm not an expert , but since it starts run roughly dies it seems to me you have a fuel pressure problem let us know if you have a laptop and a tuner you can datalog easyly hope it helps Steel
The fuel rail has the IPTS sensor on it - Injection Pressure and Temperature Sensor - you should be able to get the readings from that on the datalogger. That will tell you if you have fuel pressure. That is the one with a vacuum line on it on the driver's side fuel rail.
Mustang runs again! Thanks to some suggestions, my car is running normally again. I emptied the fuel tank and then put 5 fresh gallons of gas in. At the same time I also reloaded the stock tune and then it started right up. Put the car back to the Bama tune and everything is back to normal. Don't really know the cause, but I'm pretty sure the gas was fine so it was probably a brain fart as someone suggested. Thanks for the helpful suggestions. This spring I'll change out my plugs and hopefully that will go well. Owner1
