Backfire...

[2fst4u]

Hi...I'm having trouble with my 1984 Buick Grand National. I picked it up from a buddies dad for a great price..but can't seem to figure out why it's backfiring on me. It's been sitting for 2 years and the guy I bought it off of has another GN and put all his time into fixing that one...and the one I have was left to sit. I'm left to figure out what needs to be replaced. First things first...when I start the car up it idle's rough, when I put it in drive and step on the gas there's a loss of power and as the speed climbs it backfire's more and more...through both the exhust and throtle body. It sounds like a timing problem...but I'm not sure. If I know what's causing it...I can fix it myself. The trouble is...I'm not sure where the problem starts from. I've talked to a few people about it...some say it's a mass air flow sensor problem and others say it could be a crank or cam shaft sensor...if anyone can pin point the problem for me...would save me allot of time. Then maybe I can get down to the business of working out the kinks. My wife is driving me crazy lol...as I bought this car for her and she's yet to drive it. Thanking you all in advance for your help.

 

[turbo buicks]

try posting this in the hot air tech forum

 

[Quick6'n'-K.C.]

no, no,no, this is simple 3.8 buick trivia-- not hotair vs intercooled-

its the timing chain, if she is backfiring through the intake and exhaust, then its out of wack-

easiest way to check is to change the oil, and tear apart the oil filter-
if you see any nylon particles, chunks, or slivers{ brown in color}
then its time for a timing chain and gear set-

or- pull #1 spark plug, and easily run a hard piece of wire onto the top of the piston, BE CAREFUL, and watch for the harmonic balancer to come around to 0 ZERO.
if the balancer{ timing mark} comes around to zero, and the piston isnt all the way up { mid stroke} then you have definintely proven it is outta wack-


you can purchase the set from advanced auto for around 20.00, and then get the timing cover gaskets too-
HTH
wanner@kc.rr.com

 

[2fst4u]

Thanks for suggestion

Thanks for the suggestion, I'll try and check everything out this weekend. I was also told it could be the coil pack...cam or crank sensor...what do you think?

I'll get my hands dirty..and let you know if I fixed the problem or not. Keep you all informed as to my progress.

 

[Quick6'n'-K.C.]

YES it can be most anything wrong with the car..

since it has been parked for more than 2 years without being fixed, i would guess its a little more than the simple things-



does the car drive at all???

when you crank the engine over, does it sound ODD, as if there is no compression and the motor spins over way to quickly???

 

[2fst4u]

Sounds alright

When I start it up...it sounds fine and cranks over fine. The guy before me never drove the car at all with having 2 GN's he left this one..and babied the other. So...other than me driving it home..I'm not sure when the last time it was taken out. She's probably pissed off... from being neglected.

Thanks again...

 

[Quick6'n'-K.C.]

i jumped the gun on that one buddy-

i had no clue that the car actually drove! since it runs and drives, just runs and drives poorly-

then its typical for a car that is 18 years old!

start with the simple stuff. plugs wires o2 sensor and scan the computer for codes---

does the check engine light come on at any time??
it should when the car is first turned on, but after that it should go away-

you need to visit your local racetrack and see if there is someone there with a turbo buick that can help you out finding what is wrong with your car

HTH
bryan

 

[2fst4u]

Yeah...

Yes....it came up code 44 and 45 when I ran the codes. Changed the o2 sensor. The engine light comes on when I start it up...and then shuts off after it's started.

 

[Quick6'n'-K.C.]

http://www.turbobuick.com/forums/showthread.php?s=&threadid=31961&highlight=CODE+44

try using the search funtion at the top of the pages here-

i havent had a code 44 or 45 on any of my cars, so right now i would be shooting into the dark without getting my hands on it personally-

 

[Buick From Hell]

Actually, this thread SHOULD be at least added to hotair tech (if it's not already, but I can't do it from here)...

spittin' & backfiring ARE symptoms of jumped time, but because these engines use a chain tensioner, it's pretty rare...

Check the spark plug wiring order, 2 wires out of place will cause LOTS of weird $hit!

Could also be:
Bad ECM
Bad ignition module
Bad coil
etc etc...

 

[Quick6'n'-K.C.]

BFH-
i had a guy bring me a TTA that you would think it was a loco- motive!!
the car would spit a flame out the throttlebody 3 FEET!!!

when i pulled the motor since it needed freshening, there was only 1 tooth left from the timing gear!!!

he still has it mounted in his garage as a momento as to what years of detonation does to the stock nylon gear-

normally if a car backfires intake and exhaust, it could be the cam sensor not lined up, or the shear pin broken off-
EASY TO SEE- take the cap off the cam sensor with a phillips screw driver, and if you can spin the brass ring with the notch then the shear pin has busted-
that can throw you out into left field if your not familiar with these motors-
like i said, could be something simple

let us know what you find

wanner@kc.rr.com

 

[Rollin]

Moved to Hot air tech.....