...or I guess, more specifically, can the chip cause the converter to act erratically? I have a new chip and a new torque converter in my '91 Formula with the 700R4. When I'm cruising at a sustained speed, the car jerks from time to time. I don't think it's engine related, it's more like the converter is going in and out of a locked mode of operation for a brief moment. Can the chip cause this, or do I possibly have a converter that's not operating properly?

TIA

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jimbo

Mosquito Coast F-Body Association (MCFBA)

1991 Formula SLP350
1999 Trans Am Firehawk

[This message has been edited by jimbo (edited April 25, 2001).]

 

Yes, but if you suspect the converter of going into and out of lockup, apply light pressue on the brake pedal, this will disble the lockup, you shold also see a slight increase in the RPMs on your tach...maybe 50-100 or so.

 

right- to test lockup, depending on the stall of your convertor, once you have been crusing long enough for it to lock up, apply slight gas and touch the brake pedal. if ya find that mimics it, try adjusting the switch on the brake pedal, if it is out of adjust, slight movements in the car could cause the pedal to touch it and activate the unlock on the tc.

Steve

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86 Firebird, LG4, t-tops, 2.73 open rear, SLP 3 inch cat back exhaust, catco cat, 1 inch carb spacer, Fiberglass cowl induction hood, Formula wheels, vette servo.

Current Plans: Waiting on: rear end parts- upgrading to 373's, 28 spline axels, slp zexel torsion posi, and a disk brake setup. Also have lowering springs, front struts, and hopefully a new mild 350.


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88 Firebird Formula- deseased 2/9/99- 305 TPI, SLP 3 inch exhaust, SLP Intake runners, SLP cam, 3.45 BW disc brake posi, WS6, NOS, and all that good stuff, 13.8 on the motor, 12.89 on NOS and slicks! Hit by what else!?!? a FORD EXPLORER!!!!!!

 

...good ideas, but someone suggested that by applying the brakes you are taking a load off the engine and that in itself might eliminate or mask an engine miss. They suggested attaching a vacuum gauge to it, going for a cruise, and monitoring the gauge to see if the needle moves when the jerkiness manifests itself. Would cruising in 3rd gear instead of OD take the converter lockup out of the equation? If it did, I might be able to prove one way or the other if it's an engine problem.

 

Yes, your torque convertor can be locking and unlocking because of the eprom. But it can also be mechanical too.

I also found the EGR engaging and disengaging (which can happen in on rolling hills) can also create a similar sensation that feels like the TC locking/unlocking.

I found that setting the "minimum speed for locking the TC" and locking the EGR functioning (except under higher load conditions) removed the sensation and a much smoother ride.

[This message has been edited by Glenn91L98GTA (edited April 25, 2001).]