Car Starts Then Dies

[03 Cobra]

OKay I need some help. The initial start up fires right up. After the car is fully warm (after driving it for a bit) if i turn it off when i go to turn it back on it will start up for about 2 seconds and then die. Now if i give it a little gas after i start it, it will stay on I can even let off of the gas after about 3-5 seconds and it will stay on. At this time my car has a rough idle and feels sluggish (like lost of HP).

Here is what has been done to the car in the last 2 weeks. Not saying any of this has anything to do with why this is happening but figured some one will ask so ill post it up.

So my Compression was down # 1,2,3,5 was 148 # 4 was 138 # 6 was 115 #7,8 was 125. So I got a leak down test by ford and was told to replace or service the heads.

So I bought
2 brand new 2003 cobra heads
LDC Head Cooling Mod
Billet Flow 2.76 pulley with 4 piece idler set
Ported blower (Not a stiegemeier port)
Spark Plugs NKG
XCal 3 & a custom Tune

Got car back (March 31st) and it ran great (My compression is now at 165 across the board & car put down 472 RWHP & 452 RWTQ. I also have JLT RAI and Bassani X & catback, LFP HE & Radiator). My tuner told me that i need some new Coils. so the next week (april 5th) I had my tuner install
New Factory Coils All 8
PPRV Delete
BAP with wiring upgrade kit
MGW shifter
Inter Cooler Pump Connector (mine was cracked)

Got car back and again Car ran Great. Spoke with tuner on Friday (April 11th) and told him car is running great. Well later that day is when this first happen. Ran some errands came home and about 20 minutes later went to the store the car started then died but started right up the 2nd time so i just thought maybe i didnt have the clutch down all the way or let it up early and didnt think about it. Came out of the store and car started up then died 4 times in a row. 5th time start up (it was idling bad kinda shaky). I was like WTF!!!. So i turned it off and it did the exact same thing started and died about 4 times then start up. Went home car felt very sluggish so i did not get into the boost.

The next morning (saturday) i went out and tried to start her. She fired right up with no problems about 2-3 times in a row. Sunday morning she fired right up. After work she fired right up. Driving home almost home and it felt sluggish again i was like WTF. turned off car and went to start it up again SAME $H!7 started then turned off. did it about 3 times (idling bad again).
on the 4th time i thought what if i give it gas, so i did and it stayed on. tried again still giving it gas once it turns on and it stays on. Tried again without giving it gas and it died.

Sorry for such a long post but I really need help and did not want to leave anything out. Any input would be very much appreciated.

 

[MustangMikeKy]

sounds like a fuel pressure prob. . .

 

[JB]

sounds like a fuel pressure prob. . .

yep

first, put a new fuel filter in...

then get a fuel pressure gauge on the car or use OBD2 to read it

.

 

[About2bite]

Have you been driving it hard? I noticed you did the PPRV bypass, did you install the KB disc whe you did the delete?? Check your FRPS

 

[03 Cobra]

yep

first, put a new fuel filter in...

then get a fuel pressure gauge on the car or use OBD2 to read it

.

Sorry I forgot to mention I also install a new fuel filter. I can take it to ford and have them test the fuel pressure. Keep in mind this only happens when the car is been running for a while (fully warm). When the car is cold I do not have this problem nor is it sluggish.

 

[03 Cobra]

Have you been driving it hard? I noticed you did the PPRV bypass, did you install the KB disc whe you did the delete?? Check your FRPS

Hmm. I have drive it a little hard i mean i just got it back LOL. I did not install the KB disc not sure what it is & were can i get one. and what is FRPS (fuel Rail Pressure system)????

 

[03 Cobra]

KB Disk

Well I called KB today and ordered the KB Disk to go under FRPS :beer:
Not sure that is what is causing my problem. I will go to ford and have them do a fuel pressure test & see if I have any vacuum leaks.

I do have a BAP installed and never upgraded my FPDM (only had the BAP set to 10 until I get a upgraded FPDM). I turned it all the way down to 0 today and drove around got the car Fully warmed up (still felt sluggish after getting fully warmed up) got home and turned off the car and Tried to turn it on fired right up about 6 times in a row did not die. Only time will tell. But I still do not want the car to feel sluggish after fully warm either.

 

[03SonicSnake]

Not sure on the order of things, but it definitely sounds like a fuel issue. Did you get retuned after installing the BAP? Kinda sounds like you're either starving the engine, or almost flooding it out. You said you turned the BAP down to 0 and it doesn't die anymore but it's still rough. Maybe the FRPS (Fuel rail pressure sensor) took a dump after your problems with the BAP and the KB disc.

 

[xonecrazyx]

also a possibility of iac problem if it stays idling with foot in it

 

[About2bite]

Once you put in the KB disc you will still need a new FRPS, the disc just keeps the fuel pressure from spiking and blowing the sensor.

 

[03 Cobra]

Not sure on the order of things, but it definitely sounds like a fuel issue. Did you get retuned after installing the BAP? Kinda sounds like you're either starving the engine, or almost flooding it out. You said you turned the BAP down to 0 and it doesn't die anymore but it's still rough. Maybe the FRPS (Fuel rail pressure sensor) took a dump after your problems with the BAP and the KB disc.

Hmm no I did not get a retune after installing the BAP was I supposed to??? Yeah the BAP is still down to 0 and I can not reproduce the start then die issue but still running rough (cold & warm) & sluggish when only when fully warm. I Just oredered a KB Disk & will replace my FRPS when I put it on. I was told that since I am still running the stock pumps that I do not need to buy an upgraded FPDM but some one else told me different.

 

[03SonicSnake]

I would think that you would need a retune with a BAP since you're changing the fuel aspects of things when you put your foot into it. I would say its running rough because your FRPS is probably on its way out from fuel spikes with the BAP. Change out your FRPS and install the disc and leave your BAP at 0 until you get it tuned. You don't need an upgraded FPDM unless you're running duel Ford GT or Focus pumps because they draw more amps.

 

[duelcobras]

This sounds like an IAC valve problem, or possibly a manifold leak.

 

[Goodlife]

Possible vacuum leak as stated above. But triple check that wiring and grounds etc on the BAP. I havent wired one before but I am pretty sure you have a fuel issue.

 

[03 Cobra]

Happen again

Well the car started then died again today. The BAP is still at 0. The only thing in common from when it happens is it is hella hot out side. Like today was a very hot day and it started then died. (still only when the car is fully warmed up)

I hooked up my Xcal 3 and looked for any DTC's and there was none (no error codes thrown)

 

[03SonicSnake]

Hmmm, do you still have the problem or get it figured out? If not, maybe, just maybe it's your IAC valve. When it goes bad, your car will not run. You can crank it and it will turn over depending on if it's on it's way out or gone, the car will die right after startup or run rough and then die. Other than that, check your fuel pressure at your fuel rails to make sure your pumps are good.

 

[03 Cobra]

Hmmm, do you still have the problem or get it figured out? If not, maybe, just maybe it's your IAC valve. When it goes bad, your car will not run. You can crank it and it will turn over depending on if it's on it's way out or gone, the car will die right after startup or run rough and then die. Other than that, check your fuel pressure at your fuel rails to make sure your pumps are good.

No I have not figured it out yet. I got a new Tune (from a different tuner)& spark plugs > Same thing happens. (So I put my original tune back in)
My Alternator Just died on me. I just replaced it along with a new IC Pump (my old IC pump did not flow very well) > same thing happens But the IC Pump is Flowing now :rockon: hehe


Yesterday I just installed brand-new IAC & TPS and a new FPDM stage 2 from lethal performance :rockon:

Only time will tell if this fixes it

 

[03 Cobra]

Happen again

Well Sh1t it Happen yesterday WTF???? I do not know WTF it could be. I am tired of spending money trying to figure it out. I think I am going to have to go to the Stealer Ship. Any other suggestions?

 

[Kysnake03]

Long shot, check the intake real good for any lose connections, throttlebody cable. Fuel cut off switch in trunk.