How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Tims Auto Repair Your Own Question
Tims Auto Repair
Tims Auto Repair, GMC Mechanic
Category: GMC
Satisfied Customers: 15926
Experience:  have owned a repair shop for 25 years
Type Your GMC Question Here...
Tims Auto Repair is online now
A new question is answered every 9 seconds

I have a '98 GMC K1500 w/ 5.7. Once in awhile it won't

Customer Question

I have a '98 GMC K1500 w/ 5.7. Once in awhile it won't start. This is what it does as I try starting: fuel pump hums as it charges, starter cranks strong, fires like a regular star - but dies in a split second as if it only had time to fire a few cylinders. I try starting again and the same thing happens. As I keep trying about 1 out of 4 times it won't fire, then it fires again. It will keep doing this for 10 to 30+ attempted starts and then eventually it start and runs just fine. Sometimes I give it a Jump which doesn't seem to make a difference till the battery starts weakening cranking slower. It doesn't matter if I remove air filter or relieve vacuum pressure. It has this problem about 1 or 2 times a month, more often in summer heat and rarely in winter. I have a long list of repairs and replaced parts over the last 2 years: fuel pump, fuel relay, fuel pressure regulator, fuel filter, battery, starter, alternator, coil, spark plugs (top brand), air filter, all O2 sens ors, distributor cap and rotor and probably forgetting something. Any ideas what could cause this? ? ?
Engine light on with codes: PO102, PO171, PO174, PO303, might be more. Have cleared codes and they come back.
Another thing that could be related, sometimes truck gets in this gutless mode when I accelerate it stumbles and shakes and runs so bad it rattles the whole rig ( similar to as if there are several spark plug wires disconnected). And other times it will run good, accelerate very good.
Submitted: 11 months ago.
Category: GMC
Expert:  Mike S. replied 11 months ago.

don't crank the starter for more than 10 seconds without allowing it to cool down for 10 seconds or so.

it sounds to me as though you have either a loose connection or a security issue.

Expert:  Mike S. replied 11 months ago.

Did that answer your question? If so, kindly leave me a positive rating, so I get credit.

Expert:  Tims Auto Repair replied 11 months ago.

Hi, My name is ***** ***** for the delay.

I will do my best to assist you.

Related GMC Questions