coverter shuddering at light cruise??

[413turbo]

i've had this problem for awhile now. when the converter locks up at interstate speeds only and you are barely on the gas, just trying to maintain a steady speed, there is alot of shuddering-shaking going on. if you give it gas, it seems to pull and hold ok. seems to be locking and unlocking ok. my fuel map is smooth in the area it is occuring. seems to be worse the longer the car has been driven w/lock up on. unlock the converter and the problem goes away.

i've been told that it is probably the lockup disc. and that may be, but is there any chance it could be the solinoid, or something else? before i get the converter out and cut open. anything or anyway to get a perfect diagnosis of problem first?

 

[TurboDave]

Do you by chance have a chip with a lean cruise feature?

One or two chips back, my lean cruise did something very similar. felt like stuttering. Turns out it was just a lot of lean misfires.

Doesn't do it anymore though. Maybe lean cruise isn't as lean in my latest chip.

 

[413turbo]

i'm running e85 and xfi, i am trying to run a lean cruise. i'l richen it up in that area and give it a try. i'm willing to try anything first, before i pull the converter. that's something i haven't thought about.

 

[Thumper]

I would check your plug wires too. a light load can be a stress test on them and that can show a bad wire. Can you feel it if you just barely bring the rpm up in drive, not moving?????? I bet its a plug wire.

Thanks
Bill

 

[TurboBuRick]

That sounds exactly like a car worked on. Ended up the converter was bad.

 

[413turbo]

that's what i'm scared it'll be. but i want to make sure, it ain't cheap to get em cut and checked out.

i found someone to cut it open on a lathe for 20.00. i know where i can get parts, and i know how to tig weld, but i'm not sure if i should try that. i've never welded a converter shut before, i would imagine it should be on a jig to keep it striaght.

 

[SSedan64]

Good Info on TC assembly/disassembly here>> http://www.phoenixtrans.com/html/lockuplowdown.pdf
It's not a job for the unequiped. Has to be True & Balanced.

 

[wantattype2]

If it feels like your driving over rumble strips, change the transmission fluid first, it worked for me.

 

[THE BLACK MAMBA]

Sorry to hijack this thread but my brother is going thru the same thing with his carb. truck...it shakes at around 75 mph or in park at a light...could it also be a bad converter or going lean? sorry again

 

[meanchicken]

You can isolate if its the lock up going bad by unplugging the 4 pin plug form the driver side of the trans.
Unplug it and drive around...if the shutter is gone....so is your lock up...

 

[413turbo]

i control convertor thru xfi. on l/u is only time i have that shuddering feeling. i tried richening it up in that area, didn't help much. i'm going to pour the dr.tranny shudder stop additive in for kicks and giggles.

 

[meanchicken]

Ah...XFI....good luck with that
I'm staying with the stock computer and a TT chip.

Not knocking your gig, but from what I've studied/learned...XFI is only "needed" once you're running faster than very deep 10's or into the 9's.

I'm slap happy, daily driving in the low 11's...so...no need.

Also...if you're making 11 second or better power, getting your lock up to survive is expensive and challenging from what I've gathered.

 

[413turbo]

I understand...

i went xfi because there are alot of things going on. running e85, it had some other features i liked, and it is a big learning project for myself also.

i drive on the street(not alot) and to the track, but i don't really know where i'll stop. i may go ls motor after 1 more v6. if i decide to go that route, then i'm covered.

I've built cars before for myself and for others, (it was 10 years ago)for my last build. i almost always start with brakes and suspension, then have all the other supporting mods in place to do what you want and have a little growth room to boot.

i can size stuff accordingly, but with this car; i don't know where the end will be. so i'm only spending money once, i hope. and if i ever do go back stock, then everything can go to a roller i have sitting in the backyard. I still can't decide whether my car is a race car or a street car.

I'm thrilled w/ xfi. i have such a better understanding of how the engine uses the tune now. there was a lot of learning, but i'm starting to get pretty decent with it.

I used Eric's chips also, i give him credit. they were always dead on, he's good.