lock up question

[poppy1440]

Hello,

Is it normal to have to let off the gas a hair in order for car to go into lock up.

For instance under nornal driving at 55 mph my rpms are at 2200 unless I barely lift off gas and it seems like the car goes into lock up. I have to continuously watch rpms on sm and continue lifting off gas to bring rpms down and get any kind of gas mileage.

This is the first time I've owned a vehicle with a non factory converter so this might just be how they act I don't know.

It is a pro-torque 9.5 2800 I sent a message to eric and he said the chip should work fine with the new converter.

What do ya'll think could be going on.

 

[LOT]

L/u

Chip should control L/U @ a certain MPH. Sound to me like you are lifting and it is going into 4th.

 

[poppy1440]

It is shifting from 1-2, 2-3, 3-(4orlu) perfectly it's just the rpms don't drop after last shift until I lift off gas a touch.

According to the power logger the chip is commanding the TCC its just not doing it.

Hats off to Dave Husek(Tubo Buick Performance) who saw this thread and gave me a call today(sunday) when he saw this thread and gave me a few things to try to get this worked out.

As you can tell from log file the rpms didn't drop although the tcc was locked up until I let off gas a little

 

[poppy1440]

update
Previously I posted that the coverter would lu only when I let off gas a little but I think it really not going into lu at all. I think the drop in rpms was really just from letting off pedal.

I put a switch to ground pin A and F and put trans in 2nd and drove the car then flipped the switch and nothing. I tested the connection and f is becoming grounded when I flip the switch.

I also unplugged the harness from trans. turned the key to the on position and couldn't get voltage on any of the wires.

I also pushed the brake pedal in and manually pushed in the two buttons on the brake pedal and still nothing.

I notice that on my pl that when I flip the switch I have connecting a and f that the check doesn't come on in the pl in the tcc box. Should it?

What do you guys think might be going on?

Thanks

 

[pacecarta]

update
Previously I posted that the coverter would lu only when I let off gas a little but I think it really not going into lu at all. I think the drop in rpms was really just from letting off pedal.

I put a switch to ground pin A and F and put trans in 2nd and drove the car then flipped the switch and nothing. I tested the connection and f is becoming grounded when I flip the switch.

I also unplugged the harness from trans. turned the key to the on position and couldn't get voltage on any of the wires.

I also pushed the brake pedal in and manually pushed in the two buttons on the brake pedal and still nothing.

I notice that on my pl that when I flip the switch I have connecting a and f that the check doesn't come on in the pl in the tcc box. Should it?

What do you guys think might be going on?

Thanks

grounding the F to the A pin wont trigger the lockup flag from the ecm ,

the ecm provides the ground as does manually connecting pinF to pin A on the ALDL .. , you said you checked and didnt find any voltage at the trans connector so somewhere you have an open you need to have 12v to the lockup solenoid or it wont lock when grounded
pin a at trans connector should have 12v with the key on
check the fuse (ecm/sol fuse),
check the brake switch (pin B -voltage in pin A -out to trans connector) and that the switch body is pushed all the way up to the pedal so that the plunger that contacts the pedal arm is depressed ,

heres a link http://vortexbuicks-etc.com/tcc_lockup.htm

 

[poppy1440]

Thanks,

I checked the fuses but I'll double check tomorrow.

Also when you say check pin b are you saying unplug the plug from trans and press the button in at the brake pedal and see if I get voltage on pin b at trans. if so I did that and I didnt get any voltage on the pin. Maybe i can do the same procedure and try to ohm the wire.

 

[pacecarta]

pin B is at the brake switch , click the link and look to the left side of the diagram for the tcc circuit
pin A at the trans should have 12v key on

from the ecm/sol fuse to the B terminal out at the brake switch a terminal (purple wire) to the trans (pin A at trans connector ) can be tested for continuity (ohm it) between the switch and the trans connector pin A but if you find theres 12v at the brake switch pin A but not at the trans connector its redundant to ohm the wire because it must have an open

if you have 12v at the brake switch pin B and none at pin A and the switch is physically closed then the switch is defective
i can tell you the most common problem with TCC not working isnt that the switch is bad but that the switch isnt adjusted properly , it can slide back in its clip toward the driver and this causes the plunger to extend and theres your open , to adjust just push the swtch toward the firewall until the body contacts the pedal arm ensuring the plunger is fully seated

 

[poppy1440]

Thanks for your help.

I'll follow that procedure tomorrow I knew I saw that write up somewhere a while back but I couldn't find it. Thanks for that link

I'm thinking a bad switch because I had someone turn the key on push the brake down and reach down and push the buttons in while I was under car checking voltage at the plug. But I'll follow step by step tomorrow. $325/gal at 8-10 miles a gallon is not fun.

Thanks

 

[poppy1440]

Goodmorning, This is what I found.
I pulled the brake switch down and checked voltage. I have 12 volts pin b and voltage on pin a and c when I push in the button.

I unplugged to harness going to the trans and I don't have voltage at all. Not with the button in or out with terminal f on adl grounded or not.

What NOw.

 

[poppy1440]

ok i'm half way there. The reason conv. would lu even when a grounded a and f was the top switch was out of adjustment I found this out by taping in closed and I noticed I had 12v on pin a. The problem I have now is that apparently the ecm is not commanding lu. It will only lu if I flip the switch ground a to f. What do ya'll think.

 

[pacecarta]

if the ecm flag is on (visible on the PL) then its commanding

i dont get it first you dont have power now you do
that purple wire at the brake switch (if you have cruise its the white switch that the cruise vac line connects to ) runs from the switch to the back of the fuse block to get through the firwall to the engine side of the harness and is a straight run from there to the transmission
,

you say you can lock the TCC by ground the TCC using the aldl pin F so you're good from the ALDL to that clear dash connector as well as good from that clear connector to the main engine harness on passengerside that runs under then around the AC box then down to the trans connector uninterrupted

as for the ecm control ..you said already that it does show the flag on PL so your able to meet the conditions for lockup (vss is working and tps isnt too high )
pin A7 (tan/blk stripe) at the ecm is supposed to ground when the flag comes on ,
ohming from the ecm connector pin A7 to the trans connector should show continuity if not theres only about 10" of tan/blk wire from that connector to a factory splice joint where it joins with a group of wires that goes to a clear plastic connector behind the glove box (wrapped in foam)
make sure there are no breaks in that tan/blk wire from the ecm connector to that splice and that the connector isnt corroded or loose
if all looks good the Tcc flag can come on and still have a defective ecm because that flag only shows the command not the actual grounding..
try another ecm

 

[poppy1440]

The reason I didn't have voltage initially is because the brake pedal arm wasn't lining up with the button correctly, it's a vacuum brake convertion with different pedal.

I'll check the junkyard post to see what other ecms will work.
Could I in the meantime wire a light to the ecm that will come on when the circuit becomes complete. and then I'll know if the ecm is actually sending a ground to that wire.

 

[poppy1440]

Is there any harm in driving the car and turning the switch on and off as needed until I get this problem solved or should I park the car til I can get this problem resolved.

Thanks.

 

[pacecarta]

for the ground signal test you could hook an ohm meter or a small lamp with 12v at one side and drive to see

junkyard , doubt youll stumble upon the 7148 ecm since its only in 86-7 buick turbo (and 89 TTA) or 86 fwd (century/lesabre/olds sierra) with 3.8L buick motor

i have fast classic in my 87 and classic doesnt have lockup so i have a switch in my ashtray that i use all the time that does exactly what you plan to do so switching to have lockup theres no issue , it wont lock in 1st gear , it will unlock when you apply the brakes (provided your brake switch functions properly) it will chug a little if you just slow down without braking and forget to turn off the LU switch but it will disengage the lockup once in 1st gear so really no fear of stalling , when you do stop youll want to unlock it until you get up to 50mph or so or if your on a flat area you can lock it sooner but i wait till i'm in 3rd

 

[poppy1440]

update.

My ecm is definately fried it smells burnt and here are the pics of ecm.

Here's the problem I swapped the ecm with a know good ecm and I the converter still won't lock unless I flip the switch.

So I guess it time to start tracing wires.

 

[poppy1440]

Have ya'll given up on me?

update

checked connections from pin a7 on ecm tan with black stripe to connector behind glove box to aldl and from switch at brake pedal to switch at trans. and voltages and continuity is right in line.

I notice that I have 12 volts across pin a and f at the aldl until I press the brake.

Another thing that is strange is if I connect anything to terminal a and f the converter will lock normally. WHat I mean I volt meter even a switch even if the switch is not closed. Its like it works if the curcuit is complete although it sill open.

 

[poppy1440]

I spoke to Dave and he told me check my engine and my car runs extremely cool Average 140. He told me that by the engine running so cool its not allowing lock up. This seems to b true because under normal driving conditions the converter locks up correctly now but i notice it will come out of lu and not go back in til my cars temp rises to about 160. It will only get that high in the city. I live in the country and the engine temp hardly ever goes over 140. He said this also explains why my gas mileage is so bad