Q: Won't start without holding gas pedal to floor, stalls @ intersections

asked by on

Car all of a sudden stalled at intersection. Car starts only when pressing pedal to the floor, runs like crap until idle gets up...then seems to run/drive fine. Replaced idle air control valve. Replaced spark plugs. Bought 1-new cool pack, out of the 3 the car has and individually replaced it with no luck. Cleaned/checked Mass air flow sensor. Removed EGR valve, no visible signs although it wasn't like most GM EGR's I'm familiar with as there was really nothing that could be cleaned. Car is dumping black soot/carbon out the exhaust. My next thought is test/clean fuel injectors under intake plenum? Please help!

My car has 140 miles.
My car has an automatic transmission.

Hi there. As you already know, replacing parts without diagnoses can be expensive and time consuming without resolution. The most likely cause for the symptoms you have described is a faulty fuel pressure regulator. Removing the vacuum line to the fuel pressure regulator and turning the key to the on position, without starting, should initialize the fuel pump for two seconds. Fuel will be present at the vacuum nipple, if the regulator diaphragm has split. I recommend having your vehicle’s black soot from the exhaust be diagnosed and repaired by a certified technician, such as one from YourMechanic.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Won't start without holding gas pedal to floor, stalls @ intersections

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Q: My car key won't turn in the ignition

A number of things can make the ignition difficult or impossible to turn. A faulty ignition switch or ignition tumbler may not signal the shifter interlock properly, preventing the ignition from turning. Also, a damaged,loose, or misadjusted shifter mechanism can...

Q: Q: No brake pressure.

Hi, no pressure on your brake pedal usually means one of two things. If you have had any work done on your brakes, it is possible that there is some air in your hydraulic lines. The air simply has to...

Q: Q: Car shakes when I slow down.

Hello. The imbalance of rotating parts on a car, such as your wheel and tire assemblies, is a function of speed but also "positioning". When you were traveling at a steady state rate, say 65 MPH, the suspension was clearly...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.