back story-
car: 1991 z28, tpi, minor bolt ons, suspension, t-56 etc.

problem: car is HIGH IDLing and bucks when i attempt to drive it, stalls with foot on brake, foot off of brake, ac on- *these stalls happen after a few hesitations.

symptoms: one important symptom i found is that if i unplug the alternator the engine runs very nice. I now the alternator seems to connect to the distributor.
*** i'm very familiar w/ third gens... this is my 2nd one i've owned. anyways, i am very confused on why the car would be running so much smother while the alternator is unplugged. I did trace the wire back to the distributor, so i'm wondering what i can do to test the distributor w/ out taking it off.
*** the alternator is working fine, as i traded it in for a new one, w/ both having the same symptoms.
If anyone has any experience w/ this please help me out... getting very desperate and frustrated.
thanx-

 

okay, some more helpful possibilites.
well i just threw 55 dollars away for the IAC valve. No dice! still runs like crap. whenever i give it gas it just falls flat on it's face.
I've also changed the fuel filter, since it has been sitting a while, thought there might be some crud in there.
No dice!
*** the part that gets me is how much better she runs when i disconnect the alternator.
appreciate ANY help. thanx-

 

Do you have a timing light? If so put it on the spark plug wires one at a time and watch the pulse it should be nice and smooth. But if it is erratic you have a problem in the ignition system.

Also you can do a visual inspection on of the compontents under the distbutor cap. Our distributor's our know to have pickup coil failure. It bascially corrodes and sometimes will break up into little pieces or alot of red dust may be present. Your syptoms are actually the as when same when my distributor started failing. (fyi, the pickup coil is not the same as the ignition coil, its under the cap)

Finally, it could be your ignition module is on its way out.

Keep us posted on what you find out. Thanks

Check out this article on ignition systems, this is the system on our cars. Roll down to figures 8 and 9 in the drawings.
http://www.autozone.com/az/cds/en_us...rInfoPages.htm

 

Got codes?

 

lol... not throwing off any codes... other than the repeating "12"
thanx for the distributor .... i'm going to attempt this today.

 

okay... still not running right.

*recently changed the distributor... got the wires all mixed up but did a search and figured it out (i think) because it's running. anyways... on to the next set of "clues."
but it is "running"
i know there is some type of electrical issue, so i decided to take fuses out once at a time while it was running like crap.
*i pulled out inj #1 fuse and it immediately ran better.
HOw is this possible?
*it is running "better" but it is still not driveable.
does anyone have a clue or ever heard of this?

*so to recap, the car will idle alot better (better does not mean how it should idle, but it does stay at idle) w/ one of the INJ fuses pulled out. it does not matter which is pulled out.
* with both of the INJ fuses in the fuse block the car will fall flat on it's face.
* do the spark plug wires, or plugs have anything to do w/ this?
arrghhhhhhh! very frustrated
am most likely going to get it towed to a shop on friday.
please assist if yall ever heard of anything like this.
thanx-

 

Then I'm thinking (with disabling one bank of injecters) is there's something:

Wromg with an injector in the INJ1 bank

opr the O2 sensor is shot and you're running too much fuel based on )2 readings, for the engine to run right.

Any chance you can borrow a monitoring tool to see what the ECM is seeing?

 

well, today... lol
my buddy and i replaced all the plugs w/ ac delco's and put new wires on and put new oil and filter in there.
it was running a little decently and went to crap again.
it's going to the shop tomorrow...
hopefully the ase certified guy can fix it.... lord knows i've at least allowed him to know what it CANT be.
i will put a suggestion that it might be the injectors...?

 

Well the shop called and they basically threw in the towel.
I'm going to have it towed back to my mothers house...and there it will sit until i can work on it around Christmas time---
The following will happen... w/ hopefully positive results:
1) afpr
2) egr valve
3) new fuel injectors
4) intake gaskets
5) ecm
i'll keep everyone updated-