Hard starting when engine is warm only.

70

Asked by Dec 30, 2014 at 09:46 AM about the 2003 Chevrolet Silverado 2500HD 4 Dr LS Extended Cab SB HD

Question type: Maintenance & Repair

2003 Chey. When engine is cold engine starts and runs just great. Only when engine is
has been running and I leave it off for about 5 to 10 minutes does it have a hard time
starting. After starting it runs a little rough but then it runs fine. When I shut it off I can
smell unburned fuel/hydrocarbons.

4 Answers

85

I would check your fuel pump to begin prognosis, be sure it is fully priming the fuel line and does not make any unusual sounds. Next listen how your flywheel on your starter spins as you turn the key to start your engine (is there hesitancy, grinding, etc?). From your description you mentioned starting, rough running once started, and smell of unburned fuel, after the engine has been warmed up; which is the identifying factor here. Valves are an important part in the distribution of fuel into the engine block, after the engine warms there maybe some blockage or expansion from heat. Be sure to check your distributor cap and other electrical connections, sometimes the slightest electrical sensor misread tells the vehicle it's not working correctly when it really is. I hope this helps or at least gets you started in the right direction

1 out of 1 people think this is helpful.
23,815

Try cleaning the MAF and O2 sensors. It seems like it's a flooded condition, when starting after a brief shutdown. Like the injector driver from the computer is holding the injectors open. The PCM can't tell if the engine is hot or cold. Cleaning the throttle body may help, as well as air and coolant temp sensors too.

4 out of 4 people think this is helpful.
70

What fixed the problem was replacing the fuel presure regulator.

7 out of 7 people think this is helpful.

You must check the alternator under full load as well as check the ground wire both where it connects to the battery and the transmission. Also check the coolant level. If it is alright then you must visit car service station. https://www.yourmechanic.com/cars/chevrolet

Your Answer

Add photo

Related Questions

  • Starting problem in cold weather? 6 answers

    I have 03 Silverado HD. I'm having a hard time starting my truck in cold weather. When I start my truck it runs fine for around 4-5 minutes, than it starts missing and sometimes stalls. When I get the...

    2003 Chevrolet Silverado 2500HD 4 Dr LT 4WD Crew Cab SB HD

    -

    Maintenance & Repair

  • Truck wont shift into reverse after warming up but will go into reverse if engines cold 1 answer

    I just installed a rebuilt transmission into a 2008 GMC SIERRA, it shifts fine when first started but after it warms it won't go in reverse.

    2008 Chevrolet Silverado 2500HD LT1 Crew Cab 4WD

    -

    Maintenance & Repair

  • cold start up high pitch squealing noise from engine 3 answers

    on cold days especially when I start the truck it will squeal with accordance to the engine, when I speed up the squeal gets higher pitched. after my truck heats up to its regular temp the noise wil...

    2002 Chevrolet Silverado 2500HD 4 Dr STD Extended Cab SB HD

    -

    Maintenance & Repair

  • on cold start(25)low oil presure warning for about 2 seconds untill guage gets to 20psi 5 answers

    slowly warms to normal (40psi) Using gtx 5-30 and A/C Delco filter. Why low oil presure on startup?

    2003 Chevrolet Silverado 2500HD 2 Dr LS 4WD Standard Cab LB HD

    -

    Maintenance & Repair

  • why is my iroc z start hard when warm 2 answers

    I have a 305 tpi that has been bored and has world heads xtream energy comp cam hpertech chip header back exhaust.i just replaced starter and battery and and continue to start hard when warm

    Chevrolet Camaro

    -

    Maintenance & Repair

Silverado 2500HD

Looking for a Used Silverado 2500HD in your area?

CarGurus has 26,840 nationwide Silverado 2500HD listings starting at $1,250.

ZIP:

Search Chevrolet Silverado 2500HD Questions

Chevrolet Silverado 2500HD Experts

#1 Steven Loeffler
Steven Loeffler
Reputation 460
#2 Tom Demyan
Tom Demyan
Reputation 270
#3 piocon
piocon
Reputation 260
View All

Related Models For Sale

Used GMC Sierra 2500HD
111 Great Deals out of 14,613 listings starting at $2,650
Used Ford F-250 Super Duty
349 Great Deals out of 47,455 listings starting at $1,795
Used Chevrolet Silverado 1500
1,736 Great Deals out of 167,411 listings starting at $1,800
Used Dodge Ram 2500
148 Great Deals out of 5,290 listings starting at $2,500
Used GMC Sierra 1500
836 Great Deals out of 66,224 listings starting at $1,995
Used Ford F-150
2,221 Great Deals out of 208,349 listings starting at $1,499
Used Ford F-350 Super Duty
372 Great Deals out of 26,726 listings starting at $3,000
Used Chevrolet Silverado 2500
7 Great Deals out of 283 listings starting at $3,000
Used Chevrolet Silverado 1500HD
12 Great Deals out of 263 listings starting at $3,950
Used Toyota Tundra
471 Great Deals out of 33,233 listings starting at $3,305
Used Dodge Ram 3500
80 Great Deals out of 2,135 listings starting at $5,250

Used Cars For Sale

2017 Chevrolet Silverado 2500HD For Sale
14,757 listings starting at $25,191
2016 Chevrolet Silverado 2500HD For Sale
28 Great Deals out of 2,638 listings starting at $25,900
2015 Chevrolet Silverado 2500HD For Sale
37 Great Deals out of 1,873 listings starting at $18,500
2014 Chevrolet Silverado 2500HD For Sale
9 Great Deals out of 503 listings starting at $10,377
2013 Chevrolet Silverado 2500HD For Sale
5 Great Deals out of 959 listings starting at $7,200