08 GT Starts and then immediately dies

RR5150

New Member
Jul 14, 2019
7
0
1
55
VT
Last weekend my 08 GT started with a bad idle and then died on us while we were 250 miles away. I was able to get it started again and we made it home
but since then it will intermittently start and run ok and idle just fine until I rev it up and bit and then it will sputter and die at idle.
After that it will only fire up but not continue running, giving it gas does nothing. Lately though it only fires up and dies right away.

What I've tried:
1) Cleaned the throttle body
2) Replaced the MAS after cleaning it didn't help.
3) Replaced the fuel filter, I can hear it engage, could hear the old one too.
4) Replaced the fuel pump
5) Replaced the Throttle body motor
6) Replaced the fuel rail pressure sensor due to a CEL, CEL went out after.
7) Replaced the TPS

The CP's were replaced with Accel's about a year ago, plugs were done then too. I used a can of starting fluid to check for vacuum issues, haven't found any yet.
I can't get the car to run long enough to check for an arc.. :-/

I've run out of ideas, there are no codes.


Help?
 
  • Sponsors(?)


RR5150

New Member
Jul 14, 2019
7
0
1
55
VT
I can definitely hear it engage as did the old one before I changed it out. I'll look for 12V tomorrow.
It fires up like it wants to run strong as new but then dies.
 

fiftyslost

Member
Jan 1, 2019
9
1
13
78
Illinois
Had similar problem. The fuel shut off switch on drivers side kick panel kept tripping. I bypassed the switch and have not had a problem since. Just a thought.
 
  • Like
Reactions: Bullitt95

RR5150

New Member
Jul 14, 2019
7
0
1
55
VT
Had similar problem. The fuel shut off switch on drivers side kick panel kept tripping. I bypassed the switch and have not had a problem since. Just a thought.
That's soemthing I will have to check out for sure, thanks!
 

RR5150

New Member
Jul 14, 2019
7
0
1
55
VT
Had similar problem. The fuel shut off switch on drivers side kick panel kept tripping. I bypassed the switch and have not had a problem since. Just a thought.
I bypassed that switch today, had no change.
This morning I started the car up and it idle up and down a little bit at first and then smoothed out. I was able to rev the engine and let it return to idle. I shut it off and abd tried to start it again and I'm back where I was. It fired up strong like it wants to run and then immediately dies.
 

RR5150

New Member
Jul 14, 2019
7
0
1
55
VT
Today I learned that if I I spray brake cleaner into the intake it'll stay running just as long Iong as I keep spraying it in.
 

Shuttleman83

Member
Jun 30, 2019
98
9
18
USA
Check valve maybe restricted or faulty, try priming the fuel pump roughly 3 times in succession. Key on, off, key on, off, key on, then start. Some fuel pumps actually need this.
 
Sep 3, 2018
19
7
13
49
Johns Creek, GA
I had a similar issue that incredibly was solved by my neighbor - fuel pump just wouldn't supply fuel sporadically. Swapped the fuel pump relay with an identical relay and BAM SOLVED. The contacts just weren't making contact. WEIRD HUH. Been 6 months and 0 issues since. Car was sitting and would crank/not start, swapped relays, started immediately. Hit all the contacts with contact cleaner for good measure after that ridiculous experience.
 
  • Like
Reactions: RR5150

RR5150

New Member
Jul 14, 2019
7
0
1
55
VT
Check valve maybe restricted or faulty, try priming the fuel pump roughly 3 times in succession. Key on, off, key on, off, key on, then start. Some fuel pumps actually need this.
I tried this, no change. I also swapped a relay as Troublesome suggested.

This morning after letting it sit for a couple of days I went out and tried to start it and it fired right up, bit of a rough idle at first but it smoothed out. I then let it run for five or six minutes while I went around and started wiggling wires, etc to see if I could make it stall. I couldn't.
Eventually with me doing nothing at all is stalled out on its own. Now it just starts and dies again.

I didn't do the sending unit underneath the passenger side of the tank, I only did the complete assembly under the drivers side, could this be the issue??

THIS MAY BE FIXED:

A few days ago I got a P0193 code thrown. Fuel rail pressure sensor. I went to AutoZone and got a new one, put in on and the code went out.
Today out depsperation I put the old one back on and it FIRED RIGHT UP. I let it idle for a while and shut iff and started it again. So next I took it down the road, no issues. Could be that AutoZone sold me the wrong/bad part?? Looks like it $500 in parts later.
 
Last edited:

RR5150

New Member
Jul 14, 2019
7
0
1
55
VT
The fuel rail sensor, not the fuel rail. The part they sold me had to have failed but never tripped a code. It still running like a top.
 
Thread starter Similar threads Forum Replies Date
JustMan Dies Immediately After Start SN95 4.6L Mustang Tech 3
G Carb Engine Starts Dies Immediately Fox 5.0 Mustang Tech 3
91StangGT5.0 Cold Start: Engine dies immediately after start up Fox 5.0 Mustang Tech 19
98GTfromGA Need some help, car starts but dies immediately SN95 4.6L Mustang Tech 2
S stang starts, then immediately dies..thoughts? SN95 4.6L Mustang Tech 10
H 88 Starts sputters stall immediately Fox 5.0 Mustang Tech 6
M Idle Drops Immediately After Start, Then Fine 1994 - 1995 Specific Tech 6
atey950 Car won't start immediately after a drive.. Fox 5.0 Mustang Tech 39
racer_inboston starts, but shuts off immediately or wount start at all. Fox 5.0 Mustang Tech 6
B 1966 mustang (won't start) 1965 - 1973 Classic Mustangs -General/Talk- 3
P swapped instrument cluster - car wont start - 2011 GT 2005 - 2014 S-197 Mustang -General/Talk- 0
S 2005 Mustang V6 will not start - at my wits end! 2005 - 2009 Specific Tech 5
J Engine Help with cold starts and cold idle Fox 5.0 Mustang Tech 7
N Crank no start 1996 - 2004 SN95 Mustang -General/Talk- 2
P 1996 Saleen Starting Issues Help Please SN95 4.6L Mustang Tech 3
Nick81 SN95 Help*** 94 mustang gt 5.0l rebuild 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 6
T Engine 2013 GT Crank, but no start...no spark 2010 - 2014 Specific Tech 0
Andresquintana.mma Engine Car starts then dies Fox 5.0 Mustang Tech 15
Dan2017 Fuel 89 Mustang LX sport 5.0 stick, cranks, no start, fuel pump comes on with key doesn't shut off after 1-2 seconds Fox 5.0 Mustang Tech 3
X Another no start. Fox 5.0 Mustang Tech 3
F 97 COBRA STARTS AND DIES RIGHT AFTER SVT Tech Forum 2
N New stroker won’t start suddenly Fox 5.0 Mustang Tech 4
S Car cranks but won't start Fox 5.0 Mustang Tech 1
Driver460sz Engine Drove fine, stopped, then ran poorly, stopped, then wouldn't start. Fox 5.0 Mustang Tech 13
W Won’t start when hot 1996 - 2004 SN95 Mustang -General/Talk- 6
C Engine Performed cranks but no start checklist and no joy. Help Fox 5.0 Mustang Tech 1
J Engine cold start wierdness Fox 5.0 Mustang Tech 2
C Need help troubleshooting p1233 code. SN95 4.6L Mustang Tech 2
C Starting issues SN95 4.6L Mustang Tech 1
B Engine 86 Mustang GT 5.0 V8 Start Up RPM Fox 5.0 Mustang Tech 0
9 Fuel Help - Car Won't Start After Braided Fuel Line Conversion Fox 5.0 Mustang Tech 3
N Progress Thread 1984 mustang gt350 will not start Fox 5.0 Mustang Tech 0
8 Crank no start after warm up Fox 5.0 Mustang Tech 3
B [Project Car] 1986 5.0 V8 Foxbody Mustang Starting Issue Fox 5.0 Mustang Tech 8
rdharper02 Engine Need oil whisperer input Fox 5.0 Mustang Tech 15
A Engine Cranking but starting Fox 5.0 Mustang Tech 3
F Won’t start outside of neutral unless given gas Fox 5.0 Mustang Tech 5
H 2003 mustang v6 tick on start ups. SN95 V6 Mustang Tech 5
A Car starts but dies Fox 5.0 Mustang Tech 2
C 88 Mustang won’t start? Fox 5.0 Mustang Tech 5
M 2001 GT no start electrical issue SN95 4.6L Mustang Tech 10
Cameron96 Engine Starter meshing issue after hard starts Fox 5.0 Mustang Tech 8
T No power to the MAF Sensor 1996 - 2004 SN95 Mustang -General/Talk- 0
D Vibration on start up. SN95 V6 Mustang Tech 3
B 1999 3.8 V6 rough start and slight miss SN95 V6 Mustang Tech 0
D 2001 Mustang GT will crank but not start SN95 4.6L Mustang Tech 3
D 93 2.3 crank but no fire 2.3L (N/A & Turbo) Tech 18
C Foxbody with no start issues Fox 5.0 Mustang Tech 5
J 351w wont start after cam swap 1965 - 1973 Classic Mustangs -General/Talk- 13
B Engine Codes 81, 82, 85 and 41 - Where to start. 5.0HO/AOD transplanted into '67 Fox 5.0 Mustang Tech 14
Similar threads