Hey, I've got an 89 firebird 2.8 auto and it doesn't like me very much. most times at idle it'll just sputter and lose all vacuum (can feel it on the brake pedal) and sometimes it'll just stall alltogether. it's also horribly slow. even rapped out it has no off the line and just slightly pulls at > 4000 rpm. I know this isn't right because every now and then it'll work right for a few minutes and, in comparison, haul ***. Oh, and no codes.
what i've done:
gutted plugged up cat, ran a scantool and came up with nothing, checked fuel pressure 48psi w/o regulator, 40-41 with, replaced maf sensor, new o2 sensor, new cap/rotor/plugs/wires, checked all vacuum lines, checked all wiring. I did a bunch of other stuff to it as well, but can't think of it off the top of my head.

Any Ideas?
I think it may be running really rich cuz it eats gas like my 84 z28 with a 350

Thanks in advance

 

EGR vavle, check this. Can you get these with a warrenty, If you can, buy one put it on your car and see if it makes a difference, if not box it back up and return it.

As well there is a vaccum line down near the Distribotor and if it has a crack in it, it will cause the car to run like crap.

Then there is a large vaccum line that goes to the brake booster, if it is cracked or even slightly off, it will cause this same problem.

I know you said you checked these things, but I am just trying to point out key areas to look into.

Does your exhaust leak around the manifold. If the studs backed off some, or have burnt off, this will cause hesitation, and lack of *****.

 

I do have a small exhaust leak on the back of my driver side manifold, that is my next project.

Also I just remembered that usually when the car is acting up my lights will flicker a llittle bit and the volt gauge bounces, could it just be the volt fluctuations messing up my sensor readings?

 

Check the plug in to the alternator, A wire might be on its way out, breaking off, or something so that your Alternator is not working full time, if you think that the problem is in the plyg get another one, splice the wires and replace it.


Or maybe your Alt is on the way out. But we can hope differently.

But I do not know how the alternator going would effect the way your car idles. But it could.

 

Injectors, without a doubt...

 

i had a similar issue, no codes thrown, everything appeared ok, turns out my injectors were really dirty.

 

ok, well i thought that might be it, so i tried some additive, or is there something i can clean them with if I take them out. Or will I have to get new ones.
oh ya, and what do you guys think of my car?
it's got 4th gen trans am leather seats and a dynomax catback and that's about it. Once I get it running good i'll give it a CAI and maybe more gear...

P.S. I checked my brake booster line and it was loose so i put a new one on and it helped quite a bit, still idles bad though.

 

You could get a junkyard set, box 'em up, and send them to http://www.cruzinperformance.com . Shoot an email to Rich Jensen (of cruizin performance) and he'll give you the details. I had him service my spare set of injectors a few years ago, and it made a big improvement! I gotta send him another set soon... looks like one of 'em has clogged up.

 

We just sent them a set of injectors on Friday. You might want to rebuild your distributor, too...I couldn't believe how much difference that made, probably more than anything we have done to the V6 so far.