engine backfires help

so my engine backfires a lot just when i am speeding up mostly when i start out in first gear. some times in later gears and once in a while when just going a steady 55 to 60 mph.

i know that i have a vacuum leak and need a good tune up.

but how much should it cost to git a vacuum leak fixed and if i did and got the tune up should it stop doing that.

not going to do it myself have some one Else do it so would have to pay labor too
$125 to $150 for tune up i know

it is a 89 s-10 2.8L if that helps

Backfires are almost always timing issue's.

Make sure you get that dist and timing checked out on your tuneup.
Where's your vaccum leak?

Backfires are almost always timing issue's.

Make sure you get that dist and timing checked out on your tuneup.
Where's your vaccum leak?
I'm not sher where it is the reason i know about it is because the mechanic told me I had a pretty bad one. I know nothing about vaccum leaks at all I feel like a dumass for not knowing

he is going to check the timing

dist what are you talking about (I'm probably just having a brain far about that word)

Vaccum controlsyour timing advance on your distributor, this would make it backfire. Fix the leak and get a tune up should fix problem. Who ever works on the truck will probably charge time and parts. Take it to someone you trust and they will check timing if needed.