cyl misfire -- HELP ME PLEASE!!!!!

[97blazerct]

Hey guys!! Well I've had my blazer for about 2 years... Anyway.. A few months ago my blazer got alittle "check engine light" happy and its been a neverending problem.

The details:

1997 chevrolet blazer ls 4x4 obviously wit the 4.3vortec.

Anyway.. When I drive it.. Shes usually fine.. BUT the last FOUR times I have driven up this one hill (its a long hill) around the middle of the hill the check engine light comes on and it starts chugging or like deiseling and I lose vacuum pressure to my brakes and have NO BRAKES! Anyway, when the engine light stops flashing it starts running alright again and i regain vacuum pressure to my brakes. Everytime I run a code check on the engine light it comes back as a cyl misfire.... Sometimes 6.. Sometimes 3&6.. I changed the plug, the coil back and im out of ideas!! The second to last time it happened my truck had a STRONG SMELL of something burning but i looked and nothing was burning or leaking (as far as i could see.) When it happens.... I first start to lose power.. Like the RPMS increase but no power is going to the engine.. Then the engine light starts flashing.. Then it starts chugging/deiseling, then i lose vacuum pressure and and no brakes and need to eigher stop or like pump the gas to keep it running. Then when I stop the engine light eventually goes solid and then it runs like normal again. It looks like the plugs may be running a little lean.
Anyway.. I conclude its only when Its reving ariound 2500rpms for more then a few seconds. Its SO scary because when I lose the vacuum pressure I have no brakes and I have almost plowed into cars infront of me a few times.

Does anyone have any suggestions asto what my problem may be?? Im a working college girl and dont have the time to worry about dying when i drive!! haha! Anyway.. Please help me out, any suggestions would be GREAT!!! I'm desprite for ideas. This is becoming B.S! I cant even drive home from my boyfriends house because everytime I go up this hill the damn thing breaks down.

my email is [email protected] and if you could Email me or reply to this and help me out i'd appreciate it!

[Bads Crew]

Have you changed the fuel filter?

[Cam1959]

if engine rpm speeds up but truck slows down i would suspect slippage between motor and drivetrain.

standard or automatic transmission ?

proper tranny fluid and level ? (level too low or wrong type added ?)

since it only happens on long or steep hill i suspect fluid level related. i'd first try adding more, even a tiny bit more then full. 2 types of tranny fluid so check manual and use right type. use as little gas/engine rpm as you can get away with.

otherwise tranny needs shop to pull pan, change fluid filter, adjust stuff.

my tranny does not like prolonged heavy load. on long highway drives on long even gradual inclines, in hot weather, it gets hot and raises engine temp as it's got it's own lines thru rad to cool it.

i had to replace missing 3 of 6 bolts that hold tranny to engine. they had vibrated loose and fell out. also check 2 tranny holding bolts under tranny.

[maxwedge]

Check fuel pressure, check for the actual codes in the pcm, these are the primary diagnostic steps for this condition.

[Bads Crew]

Could be a weak fuel pump , dirty fuel filter or the SPIDER

[97blazerct]

Originally Posted by Cam1959

if engine rpm speeds up but truck slows down i would suspect slippage between motor and drivetrain.

standard or automatic transmission ?

proper tranny fluid and level ? (level too low or wrong type added ?)

since it only happens on long or steep hill i suspect fluid level related. i'd first try adding more, even a tiny bit more then full. 2 types of tranny fluid so check manual and use right type. use as little gas/engine rpm as you can get away with.

otherwise tranny needs shop to pull pan, change fluid filter, adjust stuff.

my tranny does not like prolonged heavy load. on long highway drives on long even gradual inclines, in hot weather, it gets hot and raises engine temp as it's got it's own lines thru rad to cool it.

i had to replace missing 3 of 6 bolts that hold tranny to engine. they had vibrated loose and fell out. also check 2 tranny holding bolts under tranny.

im pretty sure my levels are okay but ill check them again later.
My tranny is messed up Ill admit, but i got it rebuilt 4x!!! and it still isnt right but i have a B&M shift improver and it helps alot.
its an automatic with the shift on the floor they had in 97.

[97blazerct]

any other suggestions? im DESPRITE!!!

[97blazerct]

helppp