Jokerman

Ok i started the car just now to go get my dad and i got down the street with normal power (this is all butt dyno). I then turned onto the outer road and suddenly at about 60mph i get this massive bog no matter what speed or gear. I get to the gas station, give him the dinner order and get going back down the road and i layed into it, full tilt. It bogged and just wouldn't go really (still accelerated, but more like a honda civic with 500lbs in it, up hill) and then all of the sudden at about 40mph it jerks forward with more acceleration and power than i have felt in it (snapped the neck pretty good) and i look back and there is this puff of smoke, or dust, or debris or somthing at the point at which the car regained full power. This has happend before, but minus the neck snap. It just went away after i parked it for the day and i didn't think anything of it. It happened again today and i am starting to wonder what it is. The car was warm and it is fairly warm out side (about 89-93*F and about 60% humidity). It was about the same conditions the last time as well. Any ideas on what this is? A cat that just blew it self out, muffler doing the same, fuel pump, bad fuel, what? If this is just the cat blowing out and its not going to cause any real problems thats fine, but i want to know if its a seriouse problem and how to fix it.

By the way its a 91 rs 5.0 auto.

five7kid

iTrader: (14)

When's the last time you changed the fuel filter?

Jokerman

I haven't gotten to that yet. I thought that might be it, but could it really leave enough smoke/debris/dust to obscure a passing cars rear end? I mean it looked like i had done a burn out at 40mph but i couldn't tell you what color the smoke was for sure because it was towards sunset so the smoke was colored by the sunlight. I will change the filter though since i don't know when it was changed.

Oh and i just went out and drive it and it seems to have quite a bit more power than before the bit of bog, and i mean not just alittle like you would get by driveing when it was cooler, i mean alot, to the point were 60 comes up faster than it should.

Ukraine Train

when in park, will the engine rev quickly past 4000 without the hesitation? If it can't the prob might be a clogged cat.

heh your post reminds me of a line i saw once, "a car runs strongest right before the engine blows" or something to that effect. don't mean for that to be an omen, it's just something i remembered.

Jokerman

I can't tell what rpm everything is at exactly since my tach seems to think i have a race prepped 305 that revs past 7000rpm (in other words its out of wack). I had it do the same thing again today, not to as great as an extent as before, but the slight bog followed by the puff and weeeeeee. Yes it seems to rev fairly freely now and i think i actually have a feul filter thats causeing the problem because both times i was at about 1/2 a tank and it doesn't seem to be engine temp/exaust gas sensitive. I will chang the filter next week (since i have to work my last 12 hour night shifts at oscar mayer forever, and have to put my computer back together since the Hard drive died) and see what happens. I may have both since the cat seems to be rattling a bit and the exaust has becomre louder. Oh and if it blows up, its gonna get a carbed 350 or maybe salvage yard tpi motor.

Xenodrgn

possibly carbon breaking off the face of the piston or top of the chamber and clogging the exhaust valve? Might wanna check into that... how do your plugs look. It's not normal that for sure. I wouldn't let it go.