92 riviera NO POWER

dksob81 · #1 06-07-2008, 06:05 AM

I am working on a 1992 Buick Riviera, it has absolutely no power doesn't want to move, the engine revs fine but the car won't move until you get up to about 3000 rpms, it feels like the brakes are locked up but they are fine, the wheels spin freely. Anyone have any suggestions, I know it's in the transmission but anyone think this will be an easy fix (a bad sensor or something)

maxwedge · #2 06-07-2008, 01:56 PM

Not enough info here as you really can't say what the source is, does the trans start in 1st, can do a stall test against the torque convertor, if so what rpm does it reach.

dksob81 · #3 06-07-2008, 05:26 PM

I can't say for sure what the rpms are at, there is no tachometer in this car. I would say it is starting in first, when I put it in low 1 it does the same thing.

maxwedge · #4 06-07-2008, 08:19 PM

A bad convertor can do this ( torque convertor), but without checking/feeling this on site these are vague guesses at best.

dksob81 · #5 06-08-2008, 09:02 AM

I thought of that as well, but in reverse in runs fine, just the forward driving gears are very very very sluggish and the engine revs fine.

2lazy · #6 06-10-2008, 11:41 AM

FIRST HOW IS THERE NO TACH?!?!?! Every riviera this body style I have ever seen has teh digital cluster dashboard. Just press the button to change display config. That easy. THERE IS A TACH! :P

Anyways...

Check to make sure the Throttle valve on the transmission isnt stuck. Very easy to check. Find your throttle linkage, now see the TV transmission cable? Follow that back to the transmission housing. Should be right under the air box. Connects to the trans kinda like a spark plug boot, with a single bolt. I believe it is 10mm. Take off that bolt, remove cable. Check that valve sticking out. Make sure it doesnt stick at all, and moves up and down freely. If it is stuck in an up position, it could explain your problems. If its stuck spray some wd40 down it , and try to work it loose and free. Once you got it free, spray some good lube in, like a PTFE based or similar. A good DRY lube.

If for some odd reason it doesn't work loose, you will have to remove the trans oil pan and valve body and find out why its sticking. Thats #1 prob on these transmissions that I have encountered... Either that or your thrust washer is toast. Take yer pick.

Just remember, on that transmission, 1+2 gear are hydraulic. It very much depends on that TV cable. Also, just to be on safe side, check vacuum lines and the vacuum modulator on the trans also. Worse case you can pop on a new modulator thats adjustable, raise the pressure some and it should shift. But this is just a Band-aid fix. It will eventually go out again. Bought me over a year on my last Lesabre.

dksob81 · #7 06-10-2008, 03:13 PM

this one doesn't have digital it is analog guage cluster

maxwedge · #8 06-10-2008, 04:06 PM

Quote:

Originally Posted by 2lazy

FIRST HOW IS THERE NO TACH?!?!?! Every riviera this body style I have ever seen has teh digital cluster dashboard. Just press the button to change display config. That easy. THERE IS A TACH! :P

Anyways...

Check to make sure the Throttle valve on the transmission isnt stuck. Very easy to check. Find your throttle linkage, now see the TV transmission cable? Follow that back to the transmission housing. Should be right under the air box. Connects to the trans kinda like a spark plug boot, with a single bolt. I believe it is 10mm. Take off that bolt, remove cable. Check that valve sticking out. Make sure it doesnt stick at all, and moves up and down freely. If it is stuck in an up position, it could explain your problems. If its stuck spray some wd40 down it , and try to work it loose and free. Once you got it free, spray some good lube in, like a PTFE based or similar. A good DRY lube.

If for some odd reason it doesn't work loose, you will have to remove the trans oil pan and valve body and find out why its sticking. Thats #1 prob on these transmissions that I have encountered... Either that or your thrust washer is toast. Take yer pick.

Just remember, on that transmission, 1+2 gear are hydraulic. It very much depends on that TV cable. Also, just to be on safe side, check vacuum lines and the vacuum modulator on the trans also. Worse case you can pop on a new modulator thats adjustable, raise the pressure some and it should shift. But this is just a Band-aid fix. It will eventually go out again. Bought me over a year on my last Lesabre.

Just to clear something up, 92 fwd GM cars had electronically controlled valve bodies, no TV cable. Even if it did have a cable, even at minimum throttle pressure if the pump was good and no internal pressure losses, the car would move in DR.

2lazy · #9 06-10-2008, 04:17 PM

Wow, didnt know 92's had an optional manual cluster dash. Learn something new everyday!

As for the throttle valve, if its stuck upwards, then he would loose most line pressure. Hence why I was suggesting there first. But if it has the 4t60e, then yes, the TV cable was elimated. I hate that transmission with a passion...

If I remember correctly though, the 4t60e has a vacuum modulator still, connected to the main engine vacuum. Remove the line going to the modulator and see if any fluid has collected in the hose. Also, since the transmission is electronic, I double check the ground strap from the transmission to the firewall. Hows the fluid level and fluid color? Smell burt and brown or is it red and clean?

HotZ28 · #10 06-10-2008, 06:36 PM

Quote:

If I remember correctly though, the 4t60e has a vacuum modulator still, connected to the main engine vacuum. Remove the line going to the modulator and see if any fluid has collected in the hose.

If the car will not move, you need to have a trans shop check the line pressure. The modulator has no effect on initial line pressure. The front pump assembly delivers pressure to the entire trans, including the torque converter. If you have normal line pressure, more than likely you have a problem with the planetary gear system, or clutch hub assemblies and that requires major surgery! The modulator only has an effect on the shift points & firmness. When an engine is under a light load, or no load, high vacuum tells the modulator to move the throttle valve in one direction that allows the transmission to shift early and soft. As the engine load increases, vacuum drops lower which in turn moves the valve in the other direction causing the transmission to shift later and more firmly.

2lazy · #11 06-11-2008, 04:35 PM

Quote:

Originally Posted by HotZ28

If the car will not move, you need to have a trans shop check the line pressure. The modulator has no effect on initial line pressure. The front pump assembly delivers pressure to the entire trans, including the torque converter. If you have normal line pressure, more than likely you have a problem with the planetary gear system, or clutch hub assemblies and that requires major surgery! The modulator only has an effect on the shift points & firmness. When an engine is under a light load, or no load, high vacuum tells the modulator to move the throttle valve in one direction that allows the transmission to shift early and soft. As the engine load increases, vacuum drops lower which in turn moves the valve in the other direction causing the transmission to shift later and more firmly.

Reason I mention the modulator, is more then once I have seen it suck rust from/through the metal vacuum lines, into the diaphragm of the modulator. Once lodged inside, it can cut off almost all vacuum line pressure to the modulator itself. If its a worn transmission, this could cause a very soft condition, and in doing so with a below marginal transmission, it could slip. Just an idea. Most likely he needs a rebuild. Dont hurt checking the cheapie stuff first though! :\

Wish he give more info though...

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