Car randomly 'shuddering'

[mrblotto]

Hey all,
Yeah, I know, it's me again lol. I recently got the distributor replaced on my '97 Celica (240K). Since then I've noticed something odd. At random times (not just when engine is cold or warmed up) something........something will cause the vehicle to 'shudder'.

If I were to hazard a guess, I would say it happens mostly when I mash the pedal and the vehicle goes to automatically 'downshift'. It seems like it 'misses', causing a noticeable jerk throughout the vehicle. It'll do this like 2 times in rapid succession (under a second), then go about it's usual operation. Almost like it 'misses' upshifting the first time and has to redo it. I have tried to 'listen' to the engine to see if its 'shutting off', but it happens so randomly that I am not ever prepared.

My first guess would be something in the tranny. I dont think it's the rep distributor 'cause I'm thinking the CEL would go on (although it wouldn't hurt to plug in the scanner anyhow just in case the CEL 'light' is burnt out lol)

I did recheck the plugs/wires connections a few days ago, and they seemed fine (they were replaced when the dist got replaced). I know I need to check the tranny fluid as well. Something like it has to be in drive, or warmed up, or something when you check it. The manual will tell me.

Any ideas in the noggins of AT? Take it to a transmission shop for a look-see? Take it back to where I got the dist replaced? I'd just kinda like an idea of what may be going on before I proceed.

Danke Shern,
Blah-Toe

 

[JCH13]

If it started acting up right after you got the distributor replaced, it's probably something to do with the distributor.

 

[mrblotto]

Got home and hooked up the OBD Code reader thingee. No codes. at all. I wish there was something I could hook up then go for a drive and it would collect data the whole time. Of course that would probly only work on electrical/computer-related problems.

I'll poke around some more with a stick and see what I can find lol.

 

[JCH13]

Try a timing check, and make sure it's not something stupid like the new dist cap is loose.

 

[exdeath]

You do know to disable electronic advance with the diag port when checking/ setting base timing?

Also double check plug wires and make sure yoy didn't swap anything. Follow the arc of the distributor and make sure it goes in order 1 3 4 2.

Yes a 4 cyl will start and run on 2 cylinders.

nvm last part, didn't finish reading op

Check coil connection, rotor button, etc, full stumble like that is global and not isolated to one cylinder, you get the same stumble with a weak or damaged coil for example. Is this a 2.2? Does it have the coil built into the distributor? What were the original symptoms that caused the distributor to be replaced? Try and feel and listen for a random miss at idle too.

 

[mrblotto]

Ex,
Here's the original thread from when the whole distributor thingee was replaced. A little more than a month ago.

Of course by the time I get around to be able to check stuff today, it's snowing. And getting darker.....gah!

I did look at the distributor 'assembly' a couple days ago and pushed on the wires to ensure they're making good contact w/the dist and plugs. There didn't seem to be any 'looseness'. And the cap itself looks solid enough.

Only 'shuddered/stumbled' once today, again totally at random. I was like at 2-3k rpm, starting from a traffic light, and it just happened, like it gets out of gear or something for a 1/10 of a second. I should ride around w/a digital recorder pointing at the tach so I can actually see if it drops lol. Hell, I dont even have a decent camera to take a pic. Well, Christmas is coming up soon..............

"You do know to disable electronic advance with the diag port when checking/ setting base timing?"
I'm afraid I have no idea what that is. The garage replaced the whole distributor assembly. I did nothing. Oh, and it's a 1.8L engine.

I still would believe the CEL light would come on if it was ignition-related, but I'm not the expert by any stretch of the imagination. And it did kinda start happening when the dist got replaced. I called the garage and they said bring it on it for a look-see. I'll get there this week over lunch (only like 1/2 mile from work)

Thx again guys for your responses! *salutes*

 

[JCH13]

If it's not ignition related it may be a shift control solenoid. Have you noticed that it's mostly the 1-2 shift under moderate load or something like that? Not every single shift, but a particular gear change and load combination?