Converter Lockup problem ?

[evariste]

Evariste,
I don't know what to tell you about rebuilding it yourself. These are not simple carbs(as compared to the pre 80 quadrajets) to work on. If you were in the U.S. I'd say ship it to me and I'll fix it but I think the shipping would be expensive from France.
Sorry for the bad news, I just don't have a good solution.
Mike

Thank you Mike, even these are not so good news...

Guys..... I put in a manual override switch that locks in/out the TCC. I tapped into the disconnect circuit at the brake pedal switch. Nut

Well, it seems that I am first going to choose Nut's "bypass". I'll make photos to have it documented.

Now, I just wish to know the impact of a TPS malfunction on the motor's performances.
I'll work on 2 scenarios : removing the E4ME, and changing all that is driven by the ECM, or have this E4ME fixed. Not sure that the second is more expensive than the first !

Evariste

 

[GerryLP]

TQ Converter Replacement

Tatortot,

If you drop the tranny yourself, then replacing the coverter is as easy as pulling off the old converter and installing your replacement. If so, then ask Stingray6974 if you would be better off with a stock converter or maybe replace it with a higher stall converter. I know that if you plan to mess with the engine in the future (cam replacement for instance), then a higher TQ converter will add choices on cams latter on.

I have lowered the tranny in mine at least 5 times (total), but the last time I used a scissor-type tranny lift available at Harbor Freight Tools. It costs about $50 dollars, and you have to use a ratched to raise it or lower it, but it is alot more stable than using an adapter on the floor jack. One draw back is that you must raise your car on jack stands pretty high, so that you can roll the tranny out from under the car and back in.

I have not researched it yet, but I wonder what would involve in replacing the TCC solenoid. Does the tranny has to come out? Or are we talking tranny oil pan removal and re-installation only to gain access to it? The answer to those questions could help you decide which to do first the TCC or the converter.

GerryLP

 

[UKPaul]

Changing the Solenoid is easy. Drop the pan & remove the filter & the solenoid is held in place with a couple of 1/2" AF bolts. If it's an MX2 trans then there is a pressure switch wired in series with the solenoid which would be worth changing at the same time.
I've changed my solenoid & pressure switch, the electical system checks out & still it doesn't lock up (bypassed the ECU & earthed the solenoid ground lead manually to rule out the ECU).

Evariste: I've got manuals on setting up the E4ME. If you want I can email a copy of the TPS section to you.
Paul

 

[22229stingray81]

lockup

Thanks for the outline of the solenoid replacement, UKPaul. Im thinking about just disconnecting the lockup all together; I really dont get much better gas milage anyways, and this problem of lockup on all the time is very annoying; I dont have all my power all the time and the shifts are very rough. Is there an easy way I can disconnect the lockup (disconnecting wire or fuse) without getting an error code? Thanks for any help.

-Tatortot

 

[UKPaul]

Hi Tatortot,
A real easy way of removing lockup is to adjust the switch on the brake pedal so that it never sends 12v to the lockup circuit!
There's also the connector on the tranny. This is awkward to get to, but if you follow the wires up the side of the block they join into the main harness at another connector which is just behind the d.side valve cover. When I disconnected that connector I didn't get any error codes. There are 3 pins used on this connector: A, B & C (go to A, D & C on tranny connector). A is a constant 12V feed & B is the ground for the solenoid (goes to the TCC/EGR relay which is switched by the ECU for lockup). If you cut wire B you can then run a wire from it to a manual switch, connected to ground/earth, for a manual lockup ie. bypass the ECU. That is how I've been testing my solenoid & I definately don't get an error code (it doesn't lockup either, but that's a different problem!).
Hope this helps,
Paul

 

[22229stingray81]

lockup

Thanks for the help. I think I'll try the first approach, the second seems a little to "involved" for me.. hehe. I remember reading in the old forum about somehow converting the rear defroster switch to a lockup on/off switch? Since my rear defogger switch has stopped working and I cannot find a replacement anywhere (been looking for 3 years! 81 & 82 model year only switch, no repo part) I think I would like to try this, does anyone have this old forum post bookmarked or can tell me how to do this? Thanks for any help.

-Tatortot

 

[UKPaul]

Whatever you do, don't pull the switch right out! You won't believe how awkward it is to get back in
My defog switch is also dead (try finding one in the UK!!!). Somebody pointed me to a website for one, but the price was out of this world I just use a cloth.....
Paul

 

[22229stingray81]

lockup

Thanks for the added advice... I may have resorted to that. Can you by any chance remember the website with the outrageous prices? It just bugs me not having it working. Thanks again for any help you can give me.


-Tatortot

 

[UKPaul]

Tatortot,
I had a look through my old emails but can't find it. carparts.com may be worth a look. I'll post on another forum & see if I get any replies.
Paul

 

[22229stingray81]

lockup

Thanks again for the help, Ill go check out carparts.com right now.

-Tatortot

 

[evariste]

Evariste: I've got manuals on setting up the E4ME. If you want I can email a copy of the TPS section to you.
Paul

Thank you UKPaul, I already did all the work to adjust the TPS, but it needs to be replaced. I found a "tech tip" on how to replace it. It seems to be much too risky for me, so I'll let it as is for the moment.

I'm just evaluating two solutions :
1 - Having the carburetor rebuilt, but on this side of the ocean, it seems even more risky than in the US,
2 - Convert my old car to EFI with an Edelbrock Pro-Flo system...

Nothing before next year...

Evariste

 

[GerryLP]

If you decide to rework carburator...

Evariste,

If you decide to rework your carburator, but you also want to let someone else do it, then consider shipping your unit to an overhaul service; however, I know of one service that did not come through for me, and I wish to warn you about them.

In April of this year, I contacted Superior Carburators (a.k.a Wideworld Carburator Distributors Carburator Distributors Exchange ), and I asked them if they carried the L81 automatic Rochester carburator (P/N 17081218). I explained to them how it was important for me to receive from them that particular P/N carburator. Well, after $304.00 total, I received a carburator with a Buick P/N. I returned the item, I am still contesting the refund (which by the way the Visa people told me I would finally receive my refund/credit in the near future). I got from Superior Carburators a lot of empty promises ad.

On the other hand, I plan to send my carburator to Specialty Carburator Corporation (a.k.a. Carburator Exchange, El Monte, CA http://info@carb-x.com 1-800-491-2633). I spoke over the phone with them, and they told me that not counting shipping to and fro the sender that they could overhaul the received carburator in about a day. They have other locations, but suggested I send my factory carburator to the main location at El Monte, Ca.

If anyone else in this forum know anything negative about Specialty Carburator Co. please post the information.

I may also purchase another carburator (which type or brand I still not sure) to go with my NEW short block, NEW aluminum heads, NEW cam, and NEW rockers. I paid the core price for my original short block, and I still have my original heads, cam, and anything else that will not be used in or around the new engine. Once I rebuild them (mostly by myself I hope ) I'll have my original motor crated ready for a future install in my car.

Fixing one's vehicle is the most satisfying experience one can have. With time one can conquer anything (except perhaps cheat death... :duh) I was trying to drive my own vette to Sharkfest, so that explains hiring someone for my engine, but it did not panned-out. If your car is a daily driver, then time could be limited for you; however, if time is not a problem, then I recommend researching and repairing your own carburator. I can guarantee you that everyone here and in the CAC community will be willing to ;help you along the way. Keep the faith!

Just trying to help...

 

[22229stingray81]

trouble

Hello again all... I am sorry to post yet another problem question, but I'm worried about a few things... recently.. under middle to full throttle I am getting a heavy vibration under the floorboard, but only at low rpm, at about 3,000 it smooths out, and there is no power loss as far as i can tell. I checked transmission fluid, and changed oil and oil filter, no improvement.. is this a problem to worry about? Also I have noticed a rough idle when car is very warm... as soon as I put on gas it smoothes out, but when im at a stop, she seems to shake... related maybe? Thought id post this here cause I didnt want to bother you all with a new thread, thanks for any advice anyone can give.

-Tatortot

 

[cheeseral]

Vibration

I had an 87 Cadillac that did that and it turned out to be the converter. I had the trans replaced and it fixed the problem, I hope yours is a different prob. Sounds like your rough idle is unrelated. Good luck

 

[22229stingray81]

trouble

Thanks for the diagnosis... just what I hoped wouldnt happen... Guess I gotta have the mechanic take a close look at it.. thanks again.


-Tatortot

 

[Tom Bryant]

The ECM recieves info from the Map sensor and the TCC vac switch to engage the lock-up. It should not engage below 45 mph and should disengage when accelerating, deaccelerating or touching the brake pedal. The TCC soleniod has an internal diode which usually fails causing erratic and early lockup.

Mike

Hey Mike, Are you sure about this? Our '81 has always locked up while driving aroung town at low rpms and light throttle. It will shift 2-3 while locked at light throttle. All other functions are working correctly. A little throttle will unlock it. I have always thought that it shouldn't lock up at slow speeds. Maybe there has always been something wrong since new.

Tom

 

[22229stingray81]

So it should definatly come off with light acceleration? I have to go almost wide open to get it off, and braking wont disengage it either...

 

[Tom Bryant]

Yes. But it shouldn't unlock if your cruise control picks up a little to compensate for a slight uphill grade. It should stay locked with a slight increase in throttle but not much more.

Tom

 

[Stingray6974]

Tom,
The lock-up should never engage below 40 mph. This is a common problem with the 700R4's and the 350C trans. When you let off the gas the converter should disengage. With light throttle it will re-engage but with moderate throttle it won't. I have had them lock up as slow as 15 mph. 99% of the time replacing the solenoid cures it.

Mike

 

[Tom Bryant]

Ours will probably lock up at 20 too. Something else to check out this winter.