Here's whats up.
Driving home from a friends house and accelerate kinda quick, then go to shift, and the RPM is begged @ redline. CRAP! I'm able to kick it down for the time being and go home. Then as i'm going up my street it does it again, and pulls the accelerator pedal with it. What could be the problem? Also, when the (stock) air cleaner is in place, the 2 main barrels (the things @ the top) are cracked open when it sits in place. Took a bottle of silicone lube to the connections and did this a bit. Last time it happened i took it to a mechanic and they did this somewhere on the carb and it seemed to fix it. What could be a cause of this? I need a permanent fix.


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--Steve S--
1984 Trans Am 305 LG4, 5 speed
RPO codes point to Recaro version
Daily Driver, Flowmaster 80 Series

 

When you do this is the gas pedal also 'stuck' to the floor? Two easy things to check are if the spring is worn out and very weak or if the cable has rusted into the sleeve (disconnect it and see if it moves relatively easily inside and out of the sleeve). Anything beyond that points to some kind of binding within the carb. I'd fix this problem ASAP as LG4 valve springs are known to float at lower than redline because they are of very crappy quality

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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 Trans Am T-tops
4-bolt main 350, performer intake, headers, Holley 650, T-5, hayes clutch, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

When i came home from work, it happened again, in my quiet, wide road neighborhood. I got it in 2nd gear to govern it, and leaned over and pulled the acellerator pedal towards me, & noticed the RPM's decrease. So it is definently something from the gas pedal to the attachment to the side of the carb. I'm going to clean inside the Pedal Linkage tommorrow, hopefully that'll help, also that connecting spring is due 4 replacement.

Valve float can be noticed around 4600 RPM and up, i suppose, since it feels like i'm actually slowing down. Not that i should know...

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--Steve S--
1984 Trans Am 305 LG4, 5 speed
RPO codes point to Recaro version
Daily Driver, Flowmaster 80 Series

 

What you're expierencing is the LG4 running out of air. It now starts making less power because it can no longer breathe effectively.

Valve float is the condition where the valves don't have time to return fully return to 'resting' postion before the cam lobe hits the lifter again thus leaving the valve some amount of open all the time. The higher the revs the more severe this conditon and eventually the pistons will start slamming into the valves then the whole valve train is shot, the heads, and the pistons. You'll know when you reach the point of absolute destruction because your car will cease running with the valves bend and lifters get crushed.



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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 Trans Am T-tops
4-bolt main 350, performer intake, headers, Holley 650, T-5, hayes clutch, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

What does that sound like, when the valves are bent or the lifters get crushed?
Right now my engine makes a ticking sound.
I have a little over 135K miles on the car now, so it is due for an engine swap, (don't really want to do a rebuild on this little 305, rather get a 350.)



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Zepher
'86 Pontiac Trans Am WS6, LG4 305, 5 Speed, CF DF Clutch,
Edelbrock 1406 Carb, Edelbrock Performer RPM 7101 Intake Manifold.
Edelbrock Open Element Air Cleaner: Flowmaster Exhaust, 160* Thermostat,
Grant GT Steering Wheel, MSD HEI Coil, Taylor 8mm Wires, Leather 96 Camaro SS Seats,
Alpine CD+Changer,Alpine V12 Amps, Premier TS-1040C Subs, Polk Audio highs/mids.
Best ET: 14.94@91.67
High Speed Run: 157mph
WS6 Trans Am

 

It wouldn't be running if those happened. A bent valve wouldn't be able to recede into the head and each time that piston tried to turn over it'd smash into the valve and break your flywheel teeth/pinion gear/starter nose.

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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 Trans Am T-tops
4-bolt main 350, performer intake, headers, Holley 650, T-5, hayes clutch, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

[This message has been edited by 84FTA (edited January 28, 2001).]

 

Hey it happened today again. Seems to only happen in/ around the negighborhood for some strange reason. I was coming down the street, floored it and the tach GOES PAST REDLINE!!! I saw it goe to 6,000 and shut down, glided down the street & turned into my driveway. Obviously the acellerator cable is not an issue, what else? Is the carb really shot? If so, what would be a good replacement (Holley or Edelbrock part numbers) for the LG4 sittin underneath?

[Edit] I just took it for a spin, and nothing happened. I pinned the accelerator, and the engine (thankfully) backed off. So this only occurs occasionaly, when my car is pissed at me, i guess. Also, the cruise control cable seems to be frayed, maybe this is causing the sticking, as far as i know it is OE, so just now it removed it (whew! I hope that is the problem)
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--Steve S--
1984 Trans Am 305 LG4, 5 speed
Daily Driver, Flowmaster 80 Series

[This message has been edited by 84TransAm (edited February 08, 2001).]

[This message has been edited by 84TransAm (edited February 08, 2001).]

 

This is not a carb problem. Generally carbs just don't stick. Is it going to 6000 when you floor it in gear or not? If you're not using the CC the cable shouldn't be an issue.


Are you slamming the gas in gear then it flies to redline or are you slamming the gas, letting off the gas, and when you pull it out of gear/push the clutch in it goes to redline?

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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 Trans Am T-tops
4-bolt main 350, performer intake, headers, Holley 650, T-5, hayes clutch, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

Whats WOT mean?

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1986 Pontiac TA 305 carb.
K&N Open Air Cleaner
B&M MegaShifter

Future Mods:
3.73 gears
Nos
TransGo Shift kit
Edelbrock Perf. Carb.
Edelbrock RPM manifold

Cool car for being my first and spending $1000 at an impound auction. Had to start it with a screw driver for a bit but it's all gravy.

 

WOT= Wide Open Throttle.

84FTA: Thanks for the help. I'm replacing the spring as soon as I get out of school (driving a Ford Sucks!!) and have the cruise control disconneted, and i think it will stay that way. Picking up the 9-bolt tonight!

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--Steve S--
1984 Trans Am 305 LG4, 5 speed
Daily Driver, Flowmaster 80 Series

 

try spraying some carb cleaner ont he secondary arm and assembly (if its mechanical secondaries!) this should clean the crap off the assembly and loosen the throttle plate!

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 160 (882) heads,.447/.447 lift 222@.050 duration speed pro 327/350hp cam 350 .40 over (356) Edlebrock torker2 and a 600 edlebrock manual choke (1405)

Future mods performer rpm air gap intake (polished) comp roller cam, and way better headsa 400 defintely in the works!

 

Nothing has worked, i'm getting a Holley

 

Um, no. Stock LG4 valves float at less than 5k. Think that is enuf info for me when i see 6 grand.

 

On my 85 my secondary linkage had a nasty habit of hanging up. Fixing it was pure voodoo. I remember prying around and bending stuff on the linkage to try to get more clearance one or twice, and that worked. After that though, i had to violate the cardinal rule of carbs (keep it clean) and keep the linkage well-oiled. Normally this is a no-no, as the oil attracts dirt and can cause such problems, but in my case, if it wasn't oiled it would bind.
Since yours keeps happening real intermittently it'll be hard to simulate, but you're just gonna have to play with it till you can figure out what's binding. Next time it doews it, shut down and pull over immediately and take the AC off and take a look to see what's hanging.
...ed