Prom For 85' ...Please Help
Thread Starter
Cruising
Joined: Feb 2021
Posts: 13
Likes: 0
Prom For 85' ...Please Help
I looking for a prom for my 1985 stock Corvette with automatic transmission. This is the HLH 3200 prom GM part number 1227805. My problem is the early lock up of the torque converter at 15 mph and I believe this upgraded prom will solve the issue. Does anyone have one that I may purchase or where I could have one made. Thanks for your time.
Brian
Brian
Drifting
Joined: Mar 2006
Posts: 1,263
Likes: 188
From: Wabasha Mn
I looking for a prom for my 1985 stock Corvette with automatic transmission. This is the HLH 3200 prom GM part number 1227805. My problem is the early lock up of the torque converter at 15 mph and I believe this upgraded prom will solve the issue. Does anyone have one that I may purchase or where I could have one made. Thanks for your time.
Brian
Brian
Last edited by wilcar; Feb 21, 2021 at 12:12 PM.
Oil Producer
Joined: Apr 2014
Posts: 9,368
Likes: 2,735
What u seek is here. :
https://www.corvetteforum.com/forums...post1602976326
put a wanted add for a person to burn u a prom. give them the link to the 3200 in that post.
it will 100% solve tour issue and it took me a long time to realize that was all it was...
it will also solve a myriad of other issues. after you install it, go through the minimum idle set procedure as well.
https://www.corvetteforum.com/forums...post1602976326
put a wanted add for a person to burn u a prom. give them the link to the 3200 in that post.
it will 100% solve tour issue and it took me a long time to realize that was all it was...
it will also solve a myriad of other issues. after you install it, go through the minimum idle set procedure as well.
Thread Starter
Cruising
Joined: Feb 2021
Posts: 13
Likes: 0
VikingTrad3r the bin file link would not open for me. HLH3200 bin file here: http://www.eecis.udel.edu/~davis/z28...ib/HLH3200.BIN
I will ask on the wanted section to see if someone can burn one for me. Thanks.
I will ask on the wanted section to see if someone can burn one for me. Thanks.
Oil Producer
Joined: Apr 2014
Posts: 9,368
Likes: 2,735
There are different mods you can do to control your lockup. On my 84 C4 700r4 I eliminated lockup in 2nd and 3rd gear and in 4th gear I have a toggle switch so I can choose whether to lockup in 4th gear or not. Pretty easy to do but you have to drop the pan, disconnect a few wires and install a $10 normally open 4th gear pressure switch.
all u need is an hlh3200 in an 85.
Last edited by VikingTrad3r; Feb 21, 2021 at 09:44 PM.
Pro
Joined: Aug 2020
Posts: 647
Likes: 126
From: Liliha Bakery stuffing my face with coco puffs!
VikingTrad3r the bin file link would not open for me. HLH3200 bin file here: http://www.eecis.udel.edu/~davis/z28...ib/HLH3200.BIN
I will ask on the wanted section to see if someone can burn one for me. Thanks.
I will ask on the wanted section to see if someone can burn one for me. Thanks.
Last edited by stew86MCSS396; Feb 22, 2021 at 01:32 AM.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
VikingTrad3r the bin file link would not open for me. HLH3200 bin file here: http://www.eecis.udel.edu/~davis/z28...ib/HLH3200.BIN
I will ask on the wanted section to see if someone can burn one for me. Thanks.
I will ask on the wanted section to see if someone can burn one for me. Thanks.
I can confirm that this BIN has the minimum speed for TCC lockup set to 41 MPH. However, of course without knowing what your car's current chip is, I can't guarantee that this is the actual solution to the problem you're facing, as for all I know the chip already on your car has the same setting and there's something else going on.
Oil Producer
Joined: Apr 2014
Posts: 9,368
Likes: 2,735
sounds like Nomake Wan is your guy. he can take the hlh3200 bin and put it on your original if you send it to him. or buy a blank from him and he’ll put it on.
nomake, this issue is a HUGE DEAL with 85 autos. i had an 85 auto back in 2016 while also having an 87 auto at the same time. the 85 was undrivable (compared to the 87, which behaved like any modern automatic).
chev released this updated hlh 3200 as a fix for retarded drivability issues of the feeling of stack shifting (which was early lockup, not a 7 speed trans like it felt like)
anyway, this OP is the third person ive seen come along and i always try to help because the 85 autos are absolutely atrocious to drive otherwise.
nomake, something else that 3200 did was make the 85 idle the same as the 87. not sure how.
nomake u could advertise these as an 85 fix and keep them on the shelf. people just dont know.
it was WVZR-1 that helped me solve my issue:
https://www.corvetteforum.com/forums...orted-ecu.html
nomake, this issue is a HUGE DEAL with 85 autos. i had an 85 auto back in 2016 while also having an 87 auto at the same time. the 85 was undrivable (compared to the 87, which behaved like any modern automatic).
chev released this updated hlh 3200 as a fix for retarded drivability issues of the feeling of stack shifting (which was early lockup, not a 7 speed trans like it felt like)
anyway, this OP is the third person ive seen come along and i always try to help because the 85 autos are absolutely atrocious to drive otherwise.
nomake, something else that 3200 did was make the 85 idle the same as the 87. not sure how.
nomake u could advertise these as an 85 fix and keep them on the shelf. people just dont know.
it was WVZR-1 that helped me solve my issue:
https://www.corvetteforum.com/forums...orted-ecu.html
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
That said, I don't have a ton of them laying around, so I'm not going to go into the market of fixing everyone's '85 Corvettes. But as long as I have a few, if someone needs one, I'm more than willing to help out.
Thanks for the info.
Thread Starter
Cruising
Joined: Feb 2021
Posts: 13
Likes: 0
Thread Starter
Cruising
Joined: Feb 2021
Posts: 13
Likes: 0
Thank you VikingTrad3r for your advice. Nomake Wan has offered to make me a prom. I hope one day I can return the help.
Oil Producer
Joined: Apr 2014
Posts: 9,368
Likes: 2,735
Thank you VikingTrad3r for your advice. Nomake Wan has offered to make me a prom. I hope one day I can return the help.
perfect. that chip was the final icing on the cake for my 85. i had completely cleaned and resealed the engine.....drove like a stung bull. the factory 2200 stall made that car super fast off the line. faster than my 87
Safety Car
Joined: Aug 2009
Posts: 3,751
Likes: 275
From: Melbourne, Victoria, Australia
I looking for a prom for my 1985 stock Corvette with automatic transmission. This is the HLH 3200 prom GM part number 1227805. My problem is the early lock up of the torque converter at 15 mph and I believe this upgraded prom will solve the issue. Does anyone have one that I may purchase or where I could have one made. Thanks for your time.
Brian
Brian
Most aftermarket chips will have the update for torque converter lock up at higher rpm, i had a hypertech power chip which had that mod.
I used a toggle switch connected between the ecm plug wire going to the auto trans TCC lockup solenoid before i got the aftermarket chip.
I still have the toggle switch for track use to disable the torque converter lockup when i want, i only need to use the torque converter lock up on highway road trips to help fuel economy.
I think GM did have a recall to have the torque converter clutch lockup issue fixed to a higher speed, some had this done others missed out.
The TCC wiring comes from ECM plug terminal A7 a tan/black wire, that goes to the transmission.
Just break that wire with a toggle switch to turn it on manually when on a highway, is a simple cheap fix.
Last edited by gerardvg; Feb 22, 2021 at 07:41 PM.