1995 GMC C2500 backfire and bucking while accelerating

1995 GMC C2500
267,588 MILES • V8 • 4WD • AUTOMATIC
Avatar
NODOBO
  • MEMBER
  • 1 POST
I was traveling 70 mph and needed to accelerate, when I did the truch bucked and backfired. I let off and it ran fine. Tried it again and it was okay once and then did it repeatedly. Idles fine but when revved it sounds like I am pumping accelerater. Just got full tuneup.
Dec 5, 2009 at 8:09 AM
Avatar
RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
Oxygen sensor
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires
Dec 5, 2009 at 8:18 AM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle