350 doesn't start

Thomas Conklin

Asked by Aug 25, 2016 at 08:17 AM about the 1999 GMC Sierra Classic 1500 3 Dr K1500 SLT 4WD Extended Cab SB

Question type: Maintenance & Repair

Hello, I have a gmc 1999 k1500 with the 350 5.7
small block. When I first got it the engine had a bad
misfire. So I replaced the spark plugs and wire.
(They were in terrible condition) I need a seafoam
cleanse. Pouring straight into the break vacuum
line. The truck ran amazing after that! I drove
probably 150 miles. Until a couple days later the
truck has a hard time starting, finally getting it to
turn over I drive straight to the gas station thinking
the trucks gas gauge was messed up and I was
empty. I filled her up and put stp fuel system clean
in the gas tank. The truck kept stalling as soon as I
would let off gas or hit my breaks. Getting to a
store with my buddy he goes in to grab some stuff
I stay in the truck and rev the engine, kept it  at
2000rpm and about 3 min past and I hear a bang
and white comes out the muffler and engine dies.
It still cranks just at the of the cycle right before it
starts it klanks again. I thought I slept a rocker. So I
tear off the valve covers and the rockers are find. I
find one my spark plug for cylinder 5 had been
blasted off (the spark plug I took off was
particularly bad probably the worst in seen, when I
changed the spark plugs) a guy told me to check
fuses. I look at the fuse box in the hood and about
4 of them looked exploded, I replaced those and
still won't start. Do you think it's the timing chain

No answers yet

Your Answer

Add photo

Related Questions

Search GMC Sierra Classic 1500 Questions

GMC Sierra Classic 1500 Experts

#1 JRKMotorZ
Reputation 60
#2 John Saffrahn
John Saffrahn
Reputation 10
#2 JohnnyG013
Reputation 10
View All

Related Models For Sale

Used GMC Sierra 1500"
1,039 Great Deals out of 55,958 listings starting at $2,400
Used Chevrolet Silverado 1500"
2,408 Great Deals out of 143,311 listings starting at $1,195
Used Ford F-150"
3,193 Great Deals out of 215,835 listings starting at $1,000
Used GMC Yukon Denali"
30 Great Deals out of 4,625 listings starting at $6,900
Used Cadillac Escalade"
381 Great Deals out of 11,173 listings starting at $2,999
Used Dodge Ram 1500"
542 Great Deals out of 13,900 listings starting at $995
Used GMC Sierra 2500"
212 listings starting at $4,999
Used Toyota Tacoma"
635 Great Deals out of 29,990 listings starting at $2,850
Used Chevrolet C/K 1500"
1,146 listings starting at $2,400

Used Cars For Sale

2007 GMC Sierra Classic 1500 For Sale
10 Great Deals out of 392 listings starting at $3,900