Finished TB/WP/valve adjust, turned on and it sounds like it's gonna explode...

[davesmystery]

Alright, so this was probably the most involved repair I've ever done on a car completely by myself so I'm now way out of my comfort zone in this and very humbly open to anything at all.

For reference, here's everything I've done to/messed with on the car since it last ran. In retrospect I should have done just a few things at a time to be able to isolate any problems that might arise, but now I suppose I've learned...

Timing belt (Contitech)
Water pump (OEM)
Coolant flush (obviously)
Valve cover gasket w/plugs (OEM)
Adjusted valves
Cleaned throttle body, ICV (sprayed cleaner/wiped it down)
New gasket from throttle body to intake manifold
Inspected TPS to make sure it has two clicks
Inspected AFM and wiped some gunk out
New intake boot (Vaico)
Cam seal/o-ring/flange (OEM)
Oil Change (after dropping nut down valve oil drain)
Oxygen sensor (did the Ford 4 wire splice job)
Spark plug wires (OEM)
Spark plugs (NGK ZGR5A)
Distributor cap/rotor (OEM)
Thermostat (OEM)
Coolant Temp sensor (OEM)

I had to take various aspects apart a few times because I forgot stuff so I'm (at least I was) fairly sure I put everything back together correctly. I don't appear to be missing any bolts, etc.

I was at the point where I filled it back up with oil and was starting the coolant fill/bleed process.

The one really weird thing I should note is that it seems like the PO somehow had the hose that should go from the thermostat housing to the throttle body, goes from the thermostat housing to what appears to be the back of the block (heater core or something?). But it ran fine before with nothing plugged into the throttle body warmer at all.

So it starts but it immediately sounds like it's running at a super high idle/throttle open but there was also another sound (I can't describe it too well because turned it off fast because I freaked) but sounds like a LOUD GRRRRR, as in, very very loud with vibrato like something hitting something else. I know that's a crappy explanation but it's the best I got in the second it ran. Honestly, it sounded like an engine at it's absolute limit as soon as it starts. I'm hoping that I haven't somehow caused a valve to stick down and hit the piston. I did head a loud tick when I was hand cycling the motor while adjusting the valves, but I continued to hand cycle it and did not hear it again.

Also, I know some e30 have high idle problems but it didn't have one before this and it sounds a heck of a lot more intense than just a high idle. I have the TPS almost completely counter clockwise (just before it clicks).

Any idea of what it could be? I could make a video of it if necessary but I'm rather apprehensive about starting it again as I'm already a bit mortified as to what my hackish ways might have mangled. Any help is incredibly appreciated. Thanks!

[trippmann]

tear it down and check your timing marks again.

[KVF]

^
What he said... Also, If you give more detail about "how" you set everything up, someone may be able to see what went wrong. I.E. what clearance did you set the valves to? How did you assure valve was fully seated before adjusting? Did you ever move cam or crank while TB belt was off?

[davesmystery]

I definitely made sure both top cam gear and bottom crank were aligned with notch and O/T respectively. Valves were clearanced to 0.10"/0.25mm cold. Did not move crank or cam while timing belt was off, I didn't start valve adjust until new TB was on and tensioned. I made sure that feeler gauge was able to slide in with some resistance, not easy/not difficult.

Update - I quickly devoured a bunch of information on M20 idle speed. I got the balls to start it with the ICV unplugged. It barely idled and I'm now not hearing the crazy sound earlier, perhaps I'm just not used to how these engines sound at full throttle (never revved it past like 3k while driving), these things are damn loud! Subsequently, I've significantly calmed down.

I tested the ICV and closed it's putting out 1-2: 21.5 Ohms, 2-3: 24.5 Ohms, and 1-3: 44.5 Ohms. I put it back in closed and it started but is misfiring like crazy and only slight valve chatter near cylinders 5-6. When I throttled it, it was "sticking" at each higher idle speed, i.e. if I revved to 2k, it stuck at 2k, etc. I'm now taking TPS off to test it. Will report back, thanks for the quick responses.

[SmokeE30]

Is the throttle sticking at all? Linkage or plate itself getting stuck imtermitenly could hold the idle high like that, make sure the throttle is actually closing the butterfly when you let off

[Kozworth]

I would double check that you did not leave any hoses off, causing a vacuum leak and for the car to idle high. It is possible that with a vacuum leak you run lean, and have an adverse performance at idle.

As for the iac, its easy enough to spray carb cleaner to clean it out to make sure its not sticking. Its much easier to check these things then retear down the front covers again.

[davesmystery]

Okay, so I have no idea what I did but it's idling and running normally now after checking TPS and ICV. Throttle definitely isn't sticking, I sprayed it and the ICV with cleaner and wiped it down clean.

I ran it around the block a few times to make sure everything was running okay, then took it through emissions and it passed!