NEED HELP! She keeps stalling on me


New Member
Aug 8, 2018
Los Angeles
Quick and short.

2004 Mustang GT Vert
Current Miles 108825

Description/Problem : Ive been working on my car for the past few months. After I had a timing chain issue. Opened her up, replaced it and started to replace with (new) parts (list of work down below) a lot of other things. Ive been noticing that my car has a few symptoms after 5+ miles she begins to bog down and eventually die. Got it towed home a few times and after It sits for a few hours starts to run great again, then problem starts over. I get error code - P01233 which is fuel system is offline.

Fuel pump turns over perfectly fine when I switch the egnition, fuel pump fuse under the hood is not blown. Ive made sure all injector wires are properly plugged in, ground wires are in place.

Ive tried my hardest to do alot of research but still has the same issue. Any pointers/help/possible solutions
Will be gladly appreciated.

Addition problem - my abs, traction control, and passenger signal dash lights stay on, aswell my passenger head light looks dim when fully on.

Im assuming this entire issue is electrical, just dont know where to starts.

- Josh

[List of mods/new parts]

Clutch - 87xxx

Sparks - 87xxx

Intake Manifold - 87xxx

Fuel pump - 90xxx

Fuel filter - 90xxx

Timing chain - 107xxx

Water pump - 107xxx

Oil pump - 107xxx

Under drive pulley / belt - 107xxx

Power steering pump - 107xxx

Power steering rack - 107xxx

Lowering springs (eibach) - 107xxx

Ball joints - 107xxx

Shocks/struts (eibach) - 107xxx

Anti roll kit (eibach) - 107xxx

Battery - 107xxx

Lash Adjusters - 108500

Ignition Coils - 108500

Mass AirFlow Sensor- 108xxx

TPS Sensor - 108xxx

Exhaust - Straight pipes all the way.
I do have an header leak but will be getting new exhaust system soon.
Last edited:
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Mar 15, 2008
dallas TX
Where you having these problems before opening up the engine for the timing chain replacement?

And when you say after 5+ miles that mean every time you drive it you can only go 5+ miles before It acts up?


New Member
Aug 8, 2018
Los Angeles
Yes the first time the stalling began was before I opened her up.

It had stalled, so I went off what I thought would fix the problem and bought a new battery, assuming that was the problem.

After the timing chain install, I had a code reading misfire on cyl 2 and cyl 7 (replace coils recommended) so I did the ignition coils.

Still didnt fix stalling.

Had a code reading TPS and IAT sensor needing replacement. So I installed new TPS and IAT sensors.

All of which these codes and issues “could cause the stalling”

- Sorry for not explaining correctly.
Yes at cold start, it starts up with only a little lag before beginning to idle. Begin to drive around first 5 - 10 miles seems fine, idles fine at stops, acceleration is ok but not 100% responsive but still drivable. After 10 or so miles of driving car begins to hesitate and starts to bog. Once it gets to that point car will stall and wont stay on. Ive gotten towed home 3 times now, and everytime after sitting for a few hours and re-assuring all wires/grounds/sensors are connected right she starts up like if nothing ever happen, but the problem still comes back.

- J


SN Certified Technician
Aug 14, 2009
Houston Texas
Always post the full DTC's codes. There are 1,000's of them and they each have a story to tell. Are you still getting DTC's?

IMO you would be well served to do a through review of the car's charging system. EXPECT problems if the car's alternator, battery, and system voltage isn't spot on. Cut corners here at your own peril.

Howto perform charging system voltage drop test

When certain that the charging system is in tip top shape then begin the more detailed trouble shooting.

NOTE, sensors such as IAT and ECT work by a variable resistance that is calibrated to system voltage. Sooooooooo if the voltage is not correct this will CAUSE the sensor to not read correctly.

If this were my car I would then use an ODB2 scanner to monitor some key sensors such as:
  • IAT
  • ECT
  • TPS
  • MAF
  • Fuel pressure
  • RPM
  • EGR flow.
  • system voltage
Here's some information on an affordable Windows based ODB2 scanner with advanced graphing.

ForScan ODB2 scanner w ELM327 USB

If looking for other things to try, double check that the cluster ground is actually capable of carrying a high current. This would involve testing the black and black with white stripe all the way back to battery negative.

Also check behind the dash for evidence of water or rodent activity.

Here's some information on Cluster Printed foil trace repair.

Cluster PC foil trace repair.
Last edited:


New Member
Aug 8, 2018
Los Angeles
The DTC code I get is P1233. Also P0420, P0421 because I dont have any cats on my exhaust.


SN Certified Technician
Aug 14, 2009
Houston Texas
P1233 - Fuel System Disabled or Offline
  • Inertia fuel shutoff (IFS) switch needs to be reset
  • Open FPDM ground circuit
  • Open or shorted FPM circuit
  • Damaged IFS switch
  • Damaged FPDM
  • Damaged PCM
  • Also for Escort/Tracer and Mustang:
    • Open FPDM PWR circuit
    • Open B+ circuit to constant control relay module (CCRM) pin 11
    • Open ground to CCRM pin 18 (Mustang)
    • Damaged CCRM
  • Also for Continental:
    • Open VPWR circuit to FPDM

If this were my car I would be checking the ground in the trunk area. Review the information in the voltage drop test. Also check the trunk mounted IFS cut off switch.

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