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Help a female out


87fierochic
02-22-2009, 12:27 PM
My 87 2.8 5spd was finally fixed after wks of vaccum lines,spark plug cables, and much more. It ran well. Then after letting it warm up for 15 min, i took off ran good thru 1st, 2nd, 3rd, then when i put it in 4th it started back fireing/ bucking. i put it back in 3rd ran perfect put it back in 4th back fired about 5 times and shut done. this was while goin around 50mph. I pushed it to a driveway "who said it was a heavy car?" tried to start it and it was fireing and turning over for a couple of sec but when i tried giving it gas it dies. It also is back fireing while it was trying. I smelled ALOT of gas also. I was thinking it was the timing chain but then got to thinking it was the distributer. What do the PRO's have to say???

Ragtop_Renegade
02-23-2009, 12:26 AM
If you snapped or jumped the timing chain the engine would have died instantly.

While in theroy it's possible the distributor jumped out of time, it's not very likely. There is one thing, though. Was the spark timing adjusted recently? If the distributor hold down isn't tight enough, engine vibration can back out the bolt and cause the distributor body to rotate freely. This is certainly a resonable explination of how a engine could begin backfiring under load, then get worse, then eventually die. If you can grab the distributor body/cap and rotate it in the block, that indicates that's just what happened.

Besides spark at the wrong time, other causes of backfiring include a stuck intake valve, typically a result of a bent pushrod.

High carbon buildup on the piston tops, poor quality gasoline,or gasoline with too much ethenol blended in (depending on the engine's static compression ratio) can lead to a similar condition known as preignition, or "spark knock" as it's often called. Spark knock is extremly destructive and easily cracks, or even burns holes in piston tops.

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