Disabling TQ lockup

[mattd1979]

Is there a way to disable the Lockup of the TC in 3rd and 4th? I want to disable it temporarily to see if the shutter that I have been experiencing goes away and also to make it more driveable below 2000rpm. The shutter stops once I get above that speed and it only happens when I'm in 3rd and 4th. ThanksMatt

Modified by mattd1979 at 9:39 PM 11/16/2007
Modified by mattd1979 at 9:41 PM 11/16/2007

[Q451990]

Interesting question... I have no idea. Maybe Q45Tech has a suggestion? I wonder if it can be done with Consult?

Heath

[maxnix]

Stutter due to lugging engine at low engine speeds under load is a sign of dirty intake manifold, EGR valve, TB, etc.
Modified by maxnix at 7:21 PM 11/17/2007

[mattd1979]

The shuddering doesn't happen until 1500 rpm with TC lock up enguaged in 3rd or 4th gear and doesn't stop until just above 2000 rpm.

[Q45tech]

Terminal 5 is the poweron/off to lock up solenoid install a switch to interrupt.

Historically this shudder occurs from engine being down on torque [maybe only 10%] at partial load between 1500-1900.

New spark plugs, BG44k, and a spotless clean intake, TB, and plenum usually solve.

I'm not sure stopping lock up will tell you what you want to know vs replacing entire TC assembly which might still shudder if engine power is low in low rpms.

Try some Lubeguard RED after a transmission ATF exchange especially if the ATF is more than 2 years old [30k].

[mattd1979]

The Q is a 1990 but the engine that is in it now came out of a 1995 that we had bought which was wrecked after rearending two cop cars that were on the side of the intersate. I was told that the transmission that is in the '90 was a rebuild and that the previous payed $3000 for it. We changed the fluid in the transmission after we swapped engines and so far the transmission feels firm when it shifts until it gets to third gear at 1500 it will shudder until it gets to 2200 rpm and then shifts to 4th and repeats the shudder until 2200rpm when it clears up. The engine had around 63000 miles on it when I swapped it in.

[maxnix]

As Q45tech implied, lugging along below 2500 rpm will require a pristine intake path and as new OEM condition not to stumble.

Persoally, I never let it leave 3 in town unless I am coasting down hill. Never go up a hill either below 2500 rpm.

[Q45tech]

People forget that 4th gear is an overdrive where not only rpm are but ENGINE TORQUE and thus rear wheel torque is reduced by the same 30.6% from 3rd gear.

[mattd1979]

I installed a switch inline with the wire that goes to the lockup solenoid from the TCU and found that with it off that the stumble is not as harsh now but still noticable. After I turned it back on I noticed that it doesn't seem to lock up in 3rd but it does in 4th though not as firm as before I installed the switch. Today after work I decided to test the TPS and found that at part throttle the readings start to jump around and do not seem to get better until almost half throttle. I tested a TPS on one of our spare intakes and found one to have a nice gradual clime to 5 ohms. I installed it and took the car for a test drive and noticed that it seemed to get a tad better at cruise but still not gone. When I leave from a stop the car stumbles until I reach 2200 rpm and suddenly it runs smooth right after.

[mattd1979]

Ok. Today after work I decided to swap out ECUs for the 95 that came out of the same car that the engine came out of and soon after test driving I got a check engine light. I pulled over and pulled the codes to find a code 43 and a code 35. The 43 was TPS sensor. I replaced the TPS sensor last night with one that seemed to test out better then the one I had on the engine. Anyway I tested the sensor and found that by some chance the sensor went bad after swapping ecus because it was definetly bad tonight because the car was erratic during acceleration and when I tested it, the readings were jumping all over until half throttle. I installed yet another sensor we had off of another intake and all was good. I then decided to put the 90 ECU back in to see if the problem was just the TPS sensor but after a couple of minutes of driving it started it's bucking again, even in 1st gear. I pulled over and swapped the 95 ecu back in and so far all is good.I will let you all know tomorrow after work how it performed.

Now this is off topic but since I am posting I thought I'd ask if anyone has had an issue with a delay in the ignition switch when starting. I have to hold the key in the start position for 3 seconds and then it will start. I have already swapped the relay out of another Q that we have that works fine but there is no change.

[mattd1979]

I went ahead and posted the last paragraph of my last post as a new post under the name "4 second start delay"

Matt