hauls when cold, bogs when hot
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Joined: Aug 2005
Posts: 83
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Car: 90 IROC
Engine: 5.7 TPI
Transmission: auto 700-r4
hauls when cold, bogs when hot
well.. when i first start up and start going, it really pulls hard. when im commuting somewhere.. along the commute it feels more and more like a tired dog. when its reached operating temp and/or getting hot, and i get on the highway onramp or gun it, it sounds like air leaking or air sucking.. but all you hear is the engine roar and air.. but you dont feel the pull.. im pointing at maybe a vaccum leak or MAP sensor.. any guidance?? 
.. as a matter of fact, today i was making a left turn and i gunned it after the turn and thought i saw my SES light go on, then come off.. like it just blinked real quick.. hopefully it stored a code and ill pull it out later on today.
.. as a matter of fact, today i was making a left turn and i gunned it after the turn and thought i saw my SES light go on, then come off.. like it just blinked real quick.. hopefully it stored a code and ill pull it out later on today. 
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Get a fuel pressure gage on it and watch what happens to fuel pressure when this happens. Most likely your fuel pump is on its way out.
Thread Starter
Junior Member
Joined: Aug 2005
Posts: 83
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Car: 90 IROC
Engine: 5.7 TPI
Transmission: auto 700-r4
Originally Posted by five7kid
Get a fuel pressure gage on it and watch what happens to fuel pressure when this happens. Most likely your fuel pump is on its way out.
Thread Starter
Junior Member
Joined: Aug 2005
Posts: 83
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Car: 90 IROC
Engine: 5.7 TPI
Transmission: auto 700-r4
ahh it never came to my head about the tranny being the culprit.. but yeah.. once in a while it acts up.. or what are syptoms of a torque converter going bad.. yeah. sometimes when im slowing down to a red light, the rpms drop as youu lose momentum, but at times, the rpms bounce.. they go down to about 1,000 and as soon as the needle hits 1,000, it bounces up and then if i give it gas or something, THEN the rpms go below 1000 .. like it doesnt want to downshift.
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Joined: May 2004
Posts: 4,345
Likes: 1
From: Brighton, CO
Car: '72 Chevy Nova
Engine: Solid roller 355
Transmission: TH350
Axle/Gears: 8.5" 10-bolt 3.73 Posi
Yeah that sounds like your tranny is giving you problems for sure. If you let off the gas will it compression brake or will the rpms simply drop into neutral?
As for your original question, engines naturally run worse the hotter it is, especially if they get heat soaked. Maybe it's just because it's getting hotter out? I know my LT1 looses alot in the heat.
As for your original question, engines naturally run worse the hotter it is, especially if they get heat soaked. Maybe it's just because it's getting hotter out? I know my LT1 looses alot in the heat.
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Junior Member
Joined: Aug 2005
Posts: 83
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Car: 90 IROC
Engine: 5.7 TPI
Transmission: auto 700-r4
Originally Posted by urbanhunter44
Yeah that sounds like your tranny is giving you problems for sure. If you let off the gas will it compression brake or will the rpms simply drop into neutral?
As for your original question, engines naturally run worse the hotter it is, especially if they get heat soaked. Maybe it's just because it's getting hotter out? I know my LT1 looses alot in the heat.
As for your original question, engines naturally run worse the hotter it is, especially if they get heat soaked. Maybe it's just because it's getting hotter out? I know my LT1 looses alot in the heat.
Supreme Member
Joined: Jan 2006
Posts: 3,341
Likes: 10
From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
in the horror movie - - - - - ! THEY GOT LOST IN THE BOG !
Nope it ain’t slipping based on your description.
‘Bogs’ refers to engine RPM decreasing.
If your trans was slipping when hitting the
loud pedal it would sound great - even tho
you would not be accelerating the way you should.
Your trans might not be downshifting anymore
but that’s a separate problem.
.
Happy Racing!
.
-If people drove any slower
they’d be going backwards-
.
Joined: Jun 2005
Posts: 813
Likes: 0
From: Adrian, Mi
Car: 1989 Camaro
Engine: 350 but it's torn down right now.
Transmission: 700r4
Axle/Gears: I'm working on it,lol.
When was the last time you gave the car a tune up and changed the air filter and fuel filter?
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