1989 RS W/ 305 TBI just got it dont know its history.

My idle Is at 2,000 and climbs to 2200 after warmed up. I just rebuilt the TBI, new IAC, new TPS, the vacuum to the egr is capped. With engine running I can remove plugs from both TPS and IAC and nothing changes. Remove the maf hose from back of tbi and it idles low and rough but I can smooth it out a bit with the idle screw. If I put some suction on the maf vacuum hose using my mouth haha I can get it to idle perfectly. It has a huge exhaust leak (next on the list) but from what I know and have read since its after the headers it shouldn't affect anything.

TPS is non adjustable.

If theirs a way to delete all vacuum lines so I dont get any vacuum issues please let me know i will do it haha. I'm super lost..

Little extra info: when I got the car it idled low and decent but had no power AT ALL. Turns out the timing was way off and i have it set to 6 degrees on the tang. And now the power is back but its also what caused the idle to jump up. I'm assuming the guy ****ed with the timing to fix the idle but lost power idk.

 

START by putting the timing where it's supposed to be, and see what happens.

1. Have you verified that the timing mark on the damper hasn't shifted? When #1 is at TDC, does the mark align with the timing pointer?
2. Does the timing advance with RPM?
3. Connect a scan tool and see what the commanded idle speed is, vs. actual idle speed. Check for anything else screwy in the data stream.
4. Set the "idle screw" where it's supposed to be.
5. WHY is the "vacuum to the EGR" capped?
6. Time to invest in a REAL service manual.

 

@Schurkey
1. Yes its aligned with the timing pointer, doesnt look like its shifted.
2. How would i know this (noob)? Am i looking for the mark to shift over to the right when revving the engine?
3. Whats a good scan tool for these, never used an obd1
4. The idle screw was where its supposed to be and the idle was a little higher, i removed the cap to lower it a bit.
5. I think they started doing a delete kit.
6. I do have an online Service Manual, im just lost.

 

You've put the #1 piston at TDC, and verified? How do you know the piston was at TRUE TDC?
"Right" as seen from the driver's seat. "Left" as seen from the front of the car. (Rotates towards passenger side.) It would likely move as soon as you plugged in the one-wire connector you pulled apart to do the initial timing.
I use an elderly Snap-On MTG2500 that I got used, from eBay. The MT2500 is very similar, and costs less. Either one does not work fully on vehicles newer than 2006 in my case. I've heard of software cartridges that go newer than that (2009 at best--that's when they ended support for the 2500 series scan tool) but I've never seen one. Other folks seem to have good luck with "downloadable" programs and a mail-order wire harness that connects to the OBD port under the dash. I've never used one of those. OTC makes a professional-grade line of scan tools (Genysis, Pegysis) and there are other companies competing in the Pro market. Consumer-grade scan tools are a crapshoot. Depending on which one you buy, you may have compromised engine scanning and nothing else, full engine scanning but no ABS or Body Computer, or Airbags, or Instrument Cluster access. Or, buy the right tool and maybe get all of those features.
Once you get the problem figured out, you'll need to follow the service manual procedure to re-set the base idle speed.

The key here will be to find out what the IAC is doing or "not" doing. Thus the need to find commanded RPM vs. actual RPM.
Whatever you find...reverse it so that it's put together the way GM intended.
Forgot to mention in my previous post--do you have the correct gasket under the throttle body? There's AT LEAST two styles for the 5.0--5.7 engines. There's a few more for the 7.4L engines. An incorrect gasket could cause an air leak that would raise the idle speed.

 

@Schurkey
1. I did not physically verify this only by what the gun and tang is showing me. Whats the easiest way to verify this?

2. To be honest i dont think it moved when i plugged the wire back in at idle.... what could that tell me? I can verify this more certainly tomorrow but it pretty sure it did not move.

6. I put on the same gasket (new one of course) that was on their, so unless they put the incorrect on to begin with it should be correct.

 

Get #1 to TDC. There's a dozen ways to do this, some are more accurate than others. In this case, something as simple as a straw in the spark plug hole, turn the crank slowly by the bolt head that holds the torsional damper. When the straw is pushed as far out of the spark plug hole as possible, and then starts to go back down again, you've gone just past TDC. Back up and try again.

When you're sure the #1 piston is at TDC...look at the damper and timing pointer. It better be reading "0" or very close.

If it isn't, put a paint mark on the damper to align with "0" on the pointer, and then use the paint mark to time the engine. Plan on buying a new damper to replace the faulty one.

Try it again. Be sure.

If it doesn't move, you've probably got no electronic spark advance. Shitty power, poor fuel economy, poor throttle response. SOMETHING needs to be fixed--ECM, wire harness, or ignition module. Use the official service procedure to diagnose.

 

Oh, and since you seem to live in California, any removal or changes to vacuum lines will have you fail the smog test you have to pass every two years to keep your car registered
Have fun!
Also cruise up to the top of the page to that maroon colored bar and click on the how-tos. There's a bunch of stuff in there that will likely help you with some of your issues