I tried to search for this problem, but i'm not even sure how to describe it accuratly. My tachometer jumps around sometimes, and it's worst when accelarting. Sometimes the idle is jumpy, but not always. I know it's not just the tach b/c i actually feel the engine acting "jerky". Here is what i know to be wrong:
MAF is bad, but dissconnected
Wire from EST going to Distributor had latch broken off, but is pushed in pretty securly
no exhuast after Cat

In response to the EST wire, where can i find a new one, or replace the connector? i really don't want to spend $80 at the Pro shop for a freaking wire!
Also, i'm going to clean out the IAC and see what that does for the idle, and overall driveability

 

Try cleaning out your IAC or check you idle screw. Also check ignition coil and the plugs/wires. Check out this link for a good way to do tghe IAC https://www.thirdgen.org/newdesign/tech/tpimod2.shtml

 

I noticed your sig...did you swap the T5 into the car? Does it still have the auto tranny chip? This can explain some weird things with idle...my car does the same thing, just not all the time...it's got to do with the different IAC setup's in manual vs. auto tranny prom's.


If not, you might want to fix the things you know are wrong, like you listed, then go from there.

GO to the junkyard and pull a connector like the one on your EST wire and just wire it in....cheap and easy.

Then check / adjust the timing, then set the minimum air and check / adjust the TPS.


THEN see if the problem is still there.


HTH

 

Turns out that the distributor was just a little to loose, go figure >:O. I find this out after i spend $60 in diagnostic charges for Midas to tell me they don't know what was wrong w/ it. Whatever happened to good mechanics!? Enough of that rant.
In response to connectors, every junk yard i've even been to has refused to sell single connectors. Most of them can be found at Autozone anyway.
The T5 was standard w/ the 305, which i had and went up to the 350 (stayed w/ 305 chip)

 

That's CHEAP!!! I know you got nothing out of it, sorry to hear that, but some place charge over $100 an hour around me and the minimum is going to be 1.5 hours...

 

I suppose it coulda been worse, anyway, turns out it wasn't the distributor, but in fact, i broke one the pins in the EST input, and it would shake itself out the more i drive. I replaced the module, but my connector going into it is busted. Where can i buy individual connectors like that, or for the knock sensor?

 

My local dealer is good at keeping various pigtails for almost all the GM connectors in stock. If they don't have them, they can get them, thats what I would do. I have also seen some replacements at local auto part stores.

 

im having a similar problem, what is the est? where is it at?

 

Unfortnately, the best store i've dealt w/ thus far is autozone. Don't get me wrong, they're a quality store, but they are starting to lean toward new cars, particuarly sport compact. Anyways,

The est stands for Electronic Spark timing. Depending on your model it will be located in various places, but i suppose most likely close to the firewall. On my car, it's right next to the MAF relay, and it's known as the "powertrain module" . It's rare that this would go bad in my opinion. If your haveing the problem i had, it is likely that
a) something is loosely connected
-wires going into distributor/coil/est module
-loose spark plug wires
b) loose distributor
c) bad ign module

In my case, if i forgot to mention, it wasn't the loose distributor, but a bad connection from the est to my distributor b/c i broke one of the pins.

 

I HATE autozone. They NEVER have enough people working there. You have to wait for half an hour in line to get to the computer guy, then you have to wait in line another half hour at the register.

I't's been enough to make me go across town to Advance auto or O'Rieleys instead of the Autozone right around the corner of my house.

They have enough money to run commercials all day but not to hire a couple extra employees??

 

I HATE autozone. They NEVER have enough people working there. You have to wait for half an hour in line to get to the computer guy, then you have to wait in line another half hour at the register.

I't's been enough to make me go across town to Advance auto or O'Rieleys instead of the Autozone right around the corner of my house.

They have enough money to run commercials all day but not to hire a couple extra employees??