Is it possible that a torque converter is locked at low rpms causing the car to bog down on acceleration? If it is, how can it be fixed?

 

if it stays locked it'll kill the engine as far as i know.

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ICON Motorsports

1st & 3rd
MM Black Diamond 538 F&AM

 

If the converter is not unlocking, when you get to low speed the car will stall, Much like forgetting to take the clutch out would Do.


as far as testing it, I don't know an easy way


but if you can sit at a stopsign and idle in gear its not locked.


Also, there is a TCC unlock switch wired into the brake pedal, So it may be that the brake will deactivate it when depressed and prevent the car from dying at idle.


To test that, try idleing the car up a steep hill. if it wont die, its not locked.


Mine is manually controlled, and if I flip it on sitting in a driveway and take off the brake, it dies on me.




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

Thanks for the valuable info, guys. The knowledge keeps on coming.

 

A locked convertor won't necessarily stall the motor. It will bog down though. Mine used to do that after I went to DFI. It would lock in 1'st, 2'nd, and 3'rd, then unlock in 4'th.

[This message has been edited by RCR (edited April 20, 2001).]

 

there are a few things that control converter lockup. such as, coolant temp, and throttle position. the converter should never lock in first gear, regardless. it should lock shortly after the second gear shift and stay locked all the rest of the way up, unless you floor it, i think it unlocks then. you can also unlock the converter by hitting the brakes. when you are going down the highway keep and eye on the tach, maintain the same throttle and gently tap the brakes. when you tap the brakes the engine will speed up about 200-300 rpm, then fall back down when the converter locks back up. if the engine does not speed up when the converter unlocks, then you have a problem to diagnose starting with the brake switch on the brake pedal. at part throttle my IROC(and i think all automatic cars) will shift early and bog a little. but if i get on it, it will shift down and take off. it is annoying when driving in town with the engine lugging because the tranny shifts too early. so what i did was wire a toggle switch into my brake switch. so when i flip my toggle switch, it is as if i hit the brakes(when i really didn't)and the converter unlocks. so when i'm in town and i don't want my engine lugging, i flip my switch and the converter won't lock. but when i get out on the highway, i lock it in so i don't cook my tranny. some guys like to run with the converter locked all the time when they race. with the converter locked, the engine is directly connected to the tranny(just like a manual tranny) and you aren't losing power through the torque converter slippage. most guys claim about a 10th of a second improvement with the converter locked in.

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86 IROCZ
T-Tops
700R4
305 TPI
3.23 gears
shift kit, manual TC switch, manual fan switch, flowmaster exhaust with edelbrock TES headers& hollow cat, gutted MAF.

 

I need to get something like that wired into my brake pedal switch. It's embarassing to have a nice car limping away from a stop light when a station wagon is on your tail waiting for you to get going.

 

You should try posting your question on the trans board. I dont believe that the torque converter can lock up in first gear because of the way that the valvebody is set up from factory to prevent the car from stalling when stopping.

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86 Tramaro 90% Trans Am/ 10% IROC/Z (nose, hood,& fenders)
Trans Am Mods as of 1/10/01
3inch
T.E.S/Flowmaster setup,gutted cat,gutted maf,relocated mat,373 gears,upgraded factory chip,255 liter h/press. walpro f/pump & throttle body coolant bypass
njdaewoo@excite.com

 

yes it will do as you said in you rpost when my car was original(long long ago!) it did thid very thing it would bog like hell going around town. is ok just press the accelerator harder and it SHOULD come out of lock-up if not then you really have some trouble.


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89 firebird formula

360 11.0:1compression (350 .060 over)/fully balnced and blueprinted
comp cams xe262 cam
performer rpm intake/port matched to heads
#1407edlebrock 750
sportsman 2 heads 64cc 2.02/1.60 valves 200cc intake runner/cnc pocket ported
msd 6al/msd8.5 super condutor wires
h.e.i. proform 50,000 volt vac. advance ditributor
700r-4 with 3.08 first gear and 3.23 posi 7 5/8 rear end.
b trans shift kit(will kill shifts...suck dong!!)
shorty heddman hedders with custom 3" pipe y-pipe back(no damn cat!) with 40 series flowmaster!
griffin daul1" core rad.cutom fabrication to fit(but no cutting )

future mods: 406 roller REALLY REALLY REALLY RADICAL!!!!!