Need help! intermittent missing problem.

[THE REAL PHIL 98]

A little background information: 1998 1500 5.7 had it since i was 15. still learning a lot about these trucks. have learned a lot from this forum lol but anyways, the truck misses at high rpm. also after you get on it real hard and then go back to cruising speed (65-70 mph) it misses and eventually clears out. its not really a dead miss but its enough you can feel it. has threw a code about four times over the duration of the missing problem (around 6-7 months) same code every time: random missfire. have since installed a brand new distributor, wires and ac delco plugs, still has a missing problem. recently swapped the delco plugs for the ngk tr55 plugs. Drove it today for about a 20 mile round trip and when i got home the fuel pump whine was exceptionally loud (i know these trucks are notorious for the loud whine but it was louder than it has ever been) so i cut the truck off and cranked it back and it sounded normal again. any help will be greatly appreciated. The truck only has 80,000 miles on it so this is driving me crazy lol. thanks in advance,

 

[lha1992]

Welcome to the forum! Ive had my 89 sine I was 13-14 an by the time I started driving it at 18 the fuel pump wasn't really noticeable but shortly before the original pump went out I could hear it whine big time. Same thing with my mom's 01 suburban would whine sooooo bad the year before it went out then it would be okay then whine again an what do you kno starts missing an dies on the corner of a road an had to be towed.

Word of advise if indeed the pump is the problem get a AC Delco pump.

Sent from my GT-I9100 using Tapatalk

 

[THE REAL PHIL 98]

yeah im thinking it may be the pump. gonna do a fuel pressure test at work tomorrow. anyways thanks

 

[Scrufdog]

Yup. Check fuel pressure.