4+3 Question
Thread Starter
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
4+3 Question
I was coming home from Florida in my '85 coupe last night and my OD unit decides to downshift for no apparent reason. I was in a long left hand banking downhill and it downshifted so I thought I may have displaced enough fluid to cause a problem. Then it does it in straightaways a short time later. It does shift back up after a few minutes.
A search of this topic doesnt mention low fluids but they do mention things like the relay and the ecm for temp readings. I dont think I have a thermostat and last night it was running in the low 140* level. Would this be too low for the ecm to tell it not to be in OD? I drove it in cold temps last winter and it never did it before. Are the relays readily available? How would you test one?
Any other things I may have missed?
A search of this topic doesnt mention low fluids but they do mention things like the relay and the ecm for temp readings. I dont think I have a thermostat and last night it was running in the low 140* level. Would this be too low for the ecm to tell it not to be in OD? I drove it in cold temps last winter and it never did it before. Are the relays readily available? How would you test one?
Any other things I may have missed?
Racer
Joined: Mar 2004
Posts: 252
Likes: 1
From: Troy Illinois
Try replacing the relay (on the firewall the outside one the one in the rear is the fule pump relay) make sure the electrical conection is clean. My 1985 was acting up and this cured my problem. There was a black sludge in the electrical conector. I would also check and clean the electrical conections on the transmission. I also change the fluid every Spring. I use Mobile 1 ATF. I also installed a drain plug so I don't have to pull the pan. Good luck!
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
There are different Temps....but mine kicks out anything below 160°. I fixed all my cooling problems correctly and then put a 185° Thermostat in there and solved that from ever happening again.
I'm 99% sure it was your Temps
I'm 99% sure it was your Temps
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Thread Starter
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
I was proud my car ran so low temps but I guess this may be the problem. I checked the link Rod provided and the '85 does engage around 140* I guess I will drop in a new tstat as well as check the electrical connections before I buy the new relay.
Thanks for the great input!
Thanks for the great input!
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
I hate that it kicks out for so many different speeds etc.....the only time I like it to kick down is for passing gear on the highway.....other than that it is a PIA
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Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
I was proud my car ran so low temps but I guess this may be the problem. I checked the link Rod provided and the '85 does engage around 140* I guess I will drop in a new tstat as well as check the electrical connections before I buy the new relay.
Thanks for the great input!
Thanks for the great input!
Burning Brakes
Joined: Jan 2007
Posts: 853
Likes: 0
From: Slinger WI
Eclkers sells relay repair kits, that include the updated relays, and the relay pigtail. That is one of my winter projects is to update the relays while my engine is out. I may have alot of time to do this though, as with this horrible economy, my engine block is all I can really afford right now, as my 383 grenaded the last day before I put it in storage.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
There is always the manual option; hit the button before you drive off ( removes ECM control ) and manually engage / disengage O/d as required
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
^^it always catches me when I forget it is on......I've gotten better about remembering to Turn it off when no on the highway...but every now and again, I push in the clutch and find a gear.....
....understand, unless I am paying attention, I just grab the next gear in line when driving depending on the RPMs Then I'll be in 2nd and just accelerating along...not paying attention....and BAM that thing kicks out of O/D and I shart my pants......Hate it...Look down and I've left the O/D rocker switch on......
....understand, unless I am paying attention, I just grab the next gear in line when driving depending on the RPMs Then I'll be in 2nd and just accelerating along...not paying attention....and BAM that thing kicks out of O/D and I shart my pants......Hate it...Look down and I've left the O/D rocker switch on......
Thread Starter
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
I'm with J on that, I forget to flip the rocker after cruising then coming to a stop. Its disconcerting especially when trying to hit the interstate from the on ramp. The old"just grab 3rd" when passing is kinda funky with the OD downshifting as well. 1st with power then 2nd in OD is such a let down, lol. As long as it keeps working, I aint gonna get rid of the 23+ mpg tho, gotta love it burning that 93 octane.
When I think about it, the switch stays off til I am ready for "5th" I wish it had the button in the gear shift like the later models. I will do the TKO or ZF swap if this one kicks the bucket.
Everything will wait now til after I get back from the holiday but it looks like I will be busy with the new valve covers, LCD (no J still havent), checking and servicing the DN. Gotta love this 25+ yr old vehicle.
When I think about it, the switch stays off til I am ready for "5th" I wish it had the button in the gear shift like the later models. I will do the TKO or ZF swap if this one kicks the bucket.
Everything will wait now til after I get back from the holiday but it looks like I will be busy with the new valve covers, LCD (no J still havent), checking and servicing the DN. Gotta love this 25+ yr old vehicle.
