I have a built up auto with a Vigilante 2,800 torque converter in it and I am having some weirdness. The converter and tranny only have about 6,000 miles on them (in 3 years) and 25 1/4 mile passes, none this year at all. The last few times I have driven the car it acts really weird once it's up to temperature.

The converter locks up at 47mph in OD and then it "pulses", the RPM's jump back and forth about 300 rpm or so and it lurches or chugs or something. If I give it enough gas to unlock the converter, all is fine. It will do this all the way up to about 65mph or so and then everything is good. Then if I am taking off from a stoplight I have to give it a good amount of throttle to get it to engage, maybe 400 or 500 rpm worth and then it engages and takes off - anything less and it feels like I am not even in gear. I thought maybe I was having problems because my Breathless cold air kit is so warped and jacked up that maybe MAF was confused as to how much air it was getting. I ripped that POS out and went back to the factory setup (reset battery/ computer afterward) thinking that might fix the issue.

I drove it to the store and when I tried to leave, the car wouldn't go into reverse, just sat there and let me rev the engine at will. I shut the car down and then restarted it and it let me go but it feels like it's slipping bad. Fluid levels are normal, color is normal, smell is normal.

Any opinions on if it's the converter or is it the tranny? I think it's time for this car to go, I fix one problem and then something else happens to it. I've had it for 9 years now, 3rd engine and 2nd tranny and 129K+ miles. I love the car but I'm seriously tired of fixing it.

 

If it is in your 95 Admiral Blue Coupe then you have the 4L60E, computer controlled, transmission. It sure sounds like trans problems, to me, not the converter. Check with Pete K. for the final word.

RACE ON!!!

 

Sorry, I should have stated that it was the 4L60E in my '95. Hopefully Pete K. will chime in.

 

you can toggle the TC LU via the ALDL to help t/s

 

Which pins is it to lock/unlock/prevent it from locking?

 

It could be a hard to identify throttle position sensor, a pwm solenoid, or a bad torque converter. There are alot of low quality reman torque converters on the market. Most trans shops buy these cheaper versions. Some do not change the pwm solenoid during a rebuild, although they should.

 

Well, this is a Precision Industries Vigilante converter - not low quality by any means! What is the pwm solenoid? How would I know if they replaced it?

I paid $1,300 for the rebuild (I took it out myself) and I will have to look and see what all they did. They put a shift kit, beefier sunshell and something else.

Funny thing is, I had close to 200 passes and 123,000 miles on the stock trans and converter then have everything rebuilt and have problems in 6,000 miles

 

I did not mean to imply that vigilante makes a junk converter. That is not the case, and I missed that in the opening post. I answer many, many c4 auto trans questions, and I tend to post answers quickly.
Pwm solenoid is just that. The pwm stands for pulse width modulation.
Also, just because the vigilante converter is a high quality piece, it does not eliminate it your problem. Highly unlikely, but still possible.

 

Sounds like the bore on your lockup converter control valve is worn and causing the converter lockup problem. I literally pinned mine to stop that after I rebuilt my tranny.

As for your no move until you rev the engine, could be your pump is worn and not producing sufficent pressure to engage the forward clutch.

Unfortunately I would say it looks like its time for a tear down and rebuild.

Good luck.

BTW, Pete K is an excellent rebuilder......

 

Do you think that the problem I am having can be diagnosed with the tranny in the car? Just trying to figure out if I need to pull everything out first or take the car to the shop that built the tranny. It's very difficult for me to get the car down to the shop because I work about 60 miles from the place. I thought if I described the problem and it jumped out as "Oh, definitely the converter or definitely this" then I could just tear it down and go from there. I should probably just take it out since it sounds like I am not going to have a choice anyway.

Yuck!


Thanks for all of the help!

 

I am having the same first symptom that you described. (It's a '93 A4). Cruzing at about 49 - 53 mph in OD, I get that same pulsating of about 200 rpm. If I downshift to 3rd, it runs fine, or if I speed up to 55 in OD it runs fine. Other than that, the tranny works flawlessly. It did this with the original tranny, and still does it after it was rebuilt with a shift kit and 2500 stall tc. Help?

 

Just took my '87 to the Chevy dealer with the same symptoms... sometimes when you start it up it goes nowhere, and sometimes it goes right into gear and runs fine.

Will watch this thread closely since the dealer simply wants to start at one end of the car and replace part after part until my $ runs out.

 

My '86 was doing this on occasion too. Then my transmission crapped.

Haven't had it on the road since the rebuild, so I'm forced to wait until the spring. My rebuild came with a 12month/12,000mile warranty from the shop, so I'm not too worried about it.

Still curious about this, however.

 

Chevy dealer said the fact that my transmission works perfectly sometimes when you restart the car indicates that debri must be blocking some port when under pressure.

Of course they recommend that I bend over and let simply swap out the transmission without so much as pulling the pan to investigate further. I guess I would suggest the same thing if I didn't have a decent transmission mechanic on site. They want to order a rebuilt trans and install it for me.

It's the typical response from a "R&R" shop. They just want to "remove & replace" parts until I cry uncle or the problem stops, whichever comes first. Truth is that's the most profitable way to run a shop, so I can't blame them for wanting to run their business profitably.

Most customers don't want the headache of making multiple decisions and hearing the details of a methodical, step-by-step investigation. I'm having them drop the pan and see if they can find some debris to identify. Since there has been no slippage, it seems possible that a seal to the valve body could have degraded and pieces are floating around.

My hope is that the cost of installing a decent shift kit might solve the problem. This kind of optimism is rare among experience mechanics, though, since this can be a recipe for making fools of themselves. I just hope some dealer mechanic doesn't decide to prove me wrong by intentionally breaking the car further.

 

You should probably take it to a tranny shop instead of the dealer! My guess is that they want like $3k+ for everything? It will only be $2k at a trans shop.