Mustang Starting Issues
1/7/12, 06:29 PM
#1
NTTAWWT
Thread Starter
Mustang Starting Issues
So I've been battling an issue for a while now. Thought I had it fixed, but apparently didnt.
So occasionally, when I try to start the car after it's been on recently, like going to gas stations. When trying to start it, sound like it hits on 3-4 cylinders, then dies off. Try it again, same deal. Usually on the third try, it'll happen, then backfire. Then she starts fine, and runs normal.
I thought it was a fuel pump. I changed the plugs, cleaned the throttle body, MAF, and have kept a steady supply of fuel injector cleaner in the tank. Still having the problem. Took it to Ford, who said that it was the PCM, the computer causing the issue. Makes sense to me, since it didnt sound like the car was running quite right.
I bought a PCM, had it programmed, then didnt have any more issues, until the last couple days.
At this point, I'm honestly puzzled. Anyone with any ideas?
So occasionally, when I try to start the car after it's been on recently, like going to gas stations. When trying to start it, sound like it hits on 3-4 cylinders, then dies off. Try it again, same deal. Usually on the third try, it'll happen, then backfire. Then she starts fine, and runs normal.
I thought it was a fuel pump. I changed the plugs, cleaned the throttle body, MAF, and have kept a steady supply of fuel injector cleaner in the tank. Still having the problem. Took it to Ford, who said that it was the PCM, the computer causing the issue. Makes sense to me, since it didnt sound like the car was running quite right.
I bought a PCM, had it programmed, then didnt have any more issues, until the last couple days.
At this point, I'm honestly puzzled. Anyone with any ideas?
1/7/12, 06:35 PM
#2
A Man Just Needs Some....
Check the vacuum line on your fuel pressure regulator. Make sure fuel isn't leaking thru the vacuum port. Could also be a fuel injector leaking down. Sounds like fuel leaking and slightly flooding a couple cylinders.
1/7/12, 06:57 PM
#4
A Man Just Needs Some....
Pull the vacuum line from the regulator and see if it's wet at all or if you smell fresh fuel. Just a shot in the dark. May only do it when hot. Fuel pressure gauge would be helpful.
1/7/12, 07:05 PM
#6
Legacy TMS Member
Do you guys think a fuel pressure test would show anything? Its kinda weird that it went away for a while after the pcm was replaced. What tells the coils to spark? Is it all in the pcm? How many mile do you have on the engine? Is it throwing any codes?
1/7/12, 07:11 PM
#7
NTTAWWT
Thread Starter
it's gaining on 100k, and it throws a code for no cats. It threw one for a malfunctioning camshaft position sensor, but the ford techs said that's kind of a default code for it to throw. We checked the sensor, and it was perfectly fine.
Boner, is there anyway to check the injectors individually? I really dont wanna replace the lot of them for how much they cost.
Boner, is there anyway to check the injectors individually? I really dont wanna replace the lot of them for how much they cost.
1/7/12, 07:23 PM
#8
Bear Eats King...
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Originally Posted by StangMahn
it's gaining on 100k, and it throws a code for no cats. It threw one for a malfunctioning camshaft position sensor, but the ford techs said that's kind of a default code for it to throw. We checked the sensor, and it was perfectly fine.
Boner, is there anyway to check the injectors individually? I really dont wanna replace the lot of them for how much they cost.
Boner, is there anyway to check the injectors individually? I really dont wanna replace the lot of them for how much they cost.
You can test injectors with a Ford rotunda ids but I doubt you want to spend 10,000$ on that piece of equipment.
1/7/12, 07:45 PM
#10
A Man Just Needs Some....
First thing you have to do is figure out how to duplicate it. See if you can make it do that when you want. Really sounds like fuel. Leak down test with engine warm.
1/7/12, 07:49 PM
#12
A Man Just Needs Some....
Originally Posted by StangMahn
any good place to get a fuel pressure gauge?
1/7/12, 07:51 PM
#13
NTTAWWT
Thread Starter
i pretty well know how to replicate it once it get to be a bad problem.
should I invest in one of those inline fuel gauges in the future as a monitor?
hopefully it wont rain tomorrow, and I can get a good look at this.
should I invest in one of those inline fuel gauges in the future as a monitor?
hopefully it wont rain tomorrow, and I can get a good look at this.
1/7/12, 07:56 PM
#14
A Man Just Needs Some....
I wouldn't worry about anything inline. Just a regular tester hooked to the test port. Do you know if your car has a fuel rail pressure sensor? Those may leak fuel through the vacuum port also.
1/12/12, 09:05 AM
#19
NTTAWWT
Thread Starter
so I poked around the interweb and found this:
http://forums.anandtech.com/showthre...2054434&page=2
I still havent had a non-rainy day to check the car out, but I'm going by the ford place to speak with the guy that worked on my car to see if he has any further ideas on what to check.
http://forums.anandtech.com/showthre...2054434&page=2
I still havent had a non-rainy day to check the car out, but I'm going by the ford place to speak with the guy that worked on my car to see if he has any further ideas on what to check.
1/14/12, 03:48 PM
#20
NTTAWWT
Thread Starter
so i tried to look at the Mustang today, no vaccuum leaks that I can find. I'm going to go by the mechanics shop, get him to try the fuel pressure test and see if he can see if a (couple) of the injectors are malfunctioning. After that there's pretty much only two possibilities, a bad fuel pressure relief sensor, or a going bad fuel pump.