Skip the auto shop - Our mechanics make house calls

Q: Ocassioanl stalling at idle, RPMs fluctuate at idle - 1995 Chevrolet K2500 Suburban

asked by on

I have no problem starting the vehicle after it sat for the night, when the engine is still cold. When I drive it, park it for a short while and then get back to continue driving, I would be able to start it right away. However, the truck would turn off as soon as the key is back into the run position. So I have to keep it running for a while, and hold the fuel longer. Then the RPM would start fluctuating a lot and it would continue until I put it in gear. The idling would jump up, then drop down so much that it seems that the vehicle would stall. There are no more problems after I have put it in gear and accelerated. So, it stalls only when I try to start it after it was driven and sat for a short time. During idling, the RPMs would ocassionally go around 2900 and then gradually become normal. The repairs I've done so far include the replacement of the spark plugs, fuel filter and injectors. Also, I had the distributor, fuel pump and coil replaced. All the parts are new. Do you have any idea what might cause the stalling?

You either have a leaking injector that is dripping fuel after you shut off the engine and causing a flooded engine and will cause the hard start and erratic running conditions. You could also have a fuel pressure regulator or purge valve that is leaking. The fuel pressure regulator will need to be tested with a gauge and the purge valve tested with a vacuum pump and hose to see if it is leaking vapors when the engine is off. The purge valve may be leaking too much vapor and would show up after running and shutting it off or after getting fuel. The excessive vapors will flood the engine and cause the hard start or stall, and rough or high idles. If you would like to have this checked, a qualified pro from YourMechanic can come to your car’s location to diagnose the stalling problem and high idle to ensure proper repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • Ocassioanl stalling at idle, RPMs fluctuate at idle - 1995 Chevrolet K2500 Suburban

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: Anti-theft system activates and car stalls

Hey there. If you have a "chip key", try replacing it and re-programming to recognize the new key. Sometimes the keys will develop faults. If it is not the key, there is a specific Diagnostic Procedure for this issue in...

Q: Car continues to overheat

Hi. Although a thermostat is a possible cause of overheating, it's not the only cause for overheating. Also, if the thermostat wasn't installed correctly or the cooling system wasn't bled of air properly, it would still overheat. Other causes of...

Q: Why the MegasquirtPNP Pro ECU blew all six ignition coils at first start

Hello. From what you describe it would appear to me that the aftermarket ECU may have been the cause of the issue. I would verify that the aftermarket ECU was properly installed, as that is the only common denominator that...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.