Really SLOW acceleration under D

darkzebra · 02-08-2006, 04:45 PM

I just bought a 1988 Supra Turbo for my 16 year old son.

The car seems to have one mechanical(?) problem: it accelerates normal under R, L, 2, but creeps (really creeks) under D

Motor sounds fine during idle. There is no overheating or apparent head gasket problem.

XtreeX · 02-08-2006, 09:21 PM

I'm having the same problem with my 1990 N/A Supra. Feels like I'm giving it tons of gas but it's just not moving. Granted it's not a turbo, but still...

I took it in to have the timing belt checked out and they said it was fine. Next step is just having the catalytic converter looked at, it sounds groggly... So it it's jammed up inside then I'm just going with a all new exhaust (straight pipe).

Anyone have any ideas what else it would be? HG is fine and all pumps are in working condition, no leaks, all hoses replaced.

mrnickleye · 02-08-2006, 11:46 PM

Either take it to a shop and have the EXHAUST back pressure tested, or unbolt the exhaust pipe from the manifold and drive it to see if it improves. A plugged exhaust can give a NO power situation.

rnoswal · 02-10-2006, 04:42 AM

Sounds more like a transmission problem than engine, especially if it runs fine in the other gears.

Russ

darkzebra · 02-11-2006, 03:30 AM

I thought about tranny, but I can't understand why it would work normal in L and 2, and not in D.

Isn't L and 2 the same physical 1st and 2nd gears under D?

rnoswal · 02-11-2006, 04:40 AM

Well your selector may be out of adjustment and for some reason not starting out in 1st gear when put in D. Or it might be an internal problem. But if it runs pretty good in the other two gears then I would count out the engine as being a problem.

Russ

XtreeX · 02-12-2006, 05:21 AM

Taking it back isn't the answer, I like having an automatic. For my car, the acceleration isn't abysmal, just a little slow. I'm going to get a new exhaust and we'll see if that fixed it. If not, then I'll have to look deeper in the transmission.

rnoswal · 02-12-2006, 05:37 AM

I was just curious about something. If the car accelerates normally in R, 1 and 2 but not in D, what happens if you start the car off in D and it starts its creeping, then you pull the shifter back to 1, does it accelerate normally, quickly again? And if you put it in 2, does it shift twice or just start in 2nd and stay there?

Russ

lethalwithasupra · 02-13-2006, 09:32 AM

heh ... here's a good question ... is the MANUAL button pressed ? MANU will glow on the dash. cos if that's pressed it'll select exactly the gear you tell it to instead of climbing through them ... ?

darkzebra · 02-14-2006, 12:13 AM

I appreciate all the response.

Will try the various things tomorrow afternoon and provide feedback

02-08-2006, 04:45 PM	#1
darkzebra Stock Join Date: Feb 2006 Posts: 4	Really SLOW acceleration under D I just bought a 1988 Supra Turbo for my 16 year old son. The car seems to have one mechanical(?) problem: it accelerates normal under R, L, 2, but creeps (really creeks) under D Motor sounds fine during idle. There is no overheating or apparent head gasket problem.

02-08-2006, 11:46 PM	#3
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Either take it to a shop and have the EXHAUST back pressure tested, or unbolt the exhaust pipe from the manifold and drive it to see if it improves. A plugged exhaust can give a NO power situation. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.

02-11-2006, 03:30 AM	#5
darkzebra Stock Join Date: Feb 2006 Posts: 4	Really SLOW acceleration under D I thought about tranny, but I can't understand why it would work normal in L and 2, and not in D. Isn't L and 2 the same physical 1st and 2nd gears under D?

02-13-2006, 09:32 AM	#9
lethalwithasupra 3" Exhaust Join Date: Sep 2005 Location: south cantebury Posts: 112	heh ... here's a good question ... is the MANUAL button pressed ? MANU will glow on the dash. cos if that's pressed it'll select exactly the gear you tell it to instead of climbing through them ... ? __________________ So I bought this old Honda bike, an NSR250. Bit of a street racer, I guess. I'm told they're fast. Delivering it home with a friend driving the Supra for the first time. I drop gears and make a scream from the twin pipes flowing down this pony's flanks and it takes off like it's tail's on fire. I look back when the Honda gets to its tap-out and the Supra's only two lengths behind. No one I've let ride my bike has told me its slow, they've all loved the thing. That car is a good thing indeed.

02-14-2006, 12:13 AM	#10
darkzebra Stock Join Date: Feb 2006 Posts: 4	Really SLOW acceleration under D I appreciate all the response. Will try the various things tomorrow afternoon and provide feedback

02-08-2006, 09:21 PM	#2
XtreeX 3" Exhaust Join Date: Feb 2006 Location: Rockford, IL Posts: 92	I'm having the same problem with my 1990 N/A Supra. Feels like I'm giving it tons of gas but it's just not moving. Granted it's not a turbo, but still... I took it in to have the timing belt checked out and they said it was fine. Next step is just having the catalytic converter looked at, it sounds groggly... So it it's jammed up inside then I'm just going with a all new exhaust (straight pipe). Anyone have any ideas what else it would be? HG is fine and all pumps are in working condition, no leaks, all hoses replaced.

02-10-2006, 04:42 AM	#4
rnoswal Lexus & 550's Join Date: Apr 2005 Location: Bossier City LA Posts: 556	Sounds more like a transmission problem than engine, especially if it runs fine in the other gears. Russ

02-11-2006, 04:40 AM	#6
rnoswal Lexus & 550's Join Date: Apr 2005 Location: Bossier City LA Posts: 556	Well your selector may be out of adjustment and for some reason not starting out in 1st gear when put in D. Or it might be an internal problem. But if it runs pretty good in the other two gears then I would count out the engine as being a problem. Russ

02-12-2006, 05:21 AM	#7
XtreeX 3" Exhaust Join Date: Feb 2006 Location: Rockford, IL Posts: 92	Taking it back isn't the answer, I like having an automatic. For my car, the acceleration isn't abysmal, just a little slow. I'm going to get a new exhaust and we'll see if that fixed it. If not, then I'll have to look deeper in the transmission.

02-12-2006, 05:37 AM	#8
rnoswal Lexus & 550's Join Date: Apr 2005 Location: Bossier City LA Posts: 556	I was just curious about something. If the car accelerates normally in R, 1 and 2 but not in D, what happens if you start the car off in D and it starts its creeping, then you pull the shifter back to 1, does it accelerate normally, quickly again? And if you put it in 2, does it shift twice or just start in 2nd and stay there? Russ

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