3VZ-FE low and rough idle - help please

[Rdubs]

Hi all,
3VZ-FE going into a 94 N/A. Engine/tran is installed and wiring is done, but am waiting to put on the axles, coolant hoses, exhaust, charcoal cannister, throttle cable until I make sure the engine is running right and I don't need to pull it. Initially I had a problem with the engine starting then quitting after a second which was solved by searching and finding a post where Paul Woods said to check the earthing strap on the AFM relay from the COR, it wasn't earthed so now it starts and idles. However the idle is terrible, it idles around 500-550 RPM (with the V6 tach installed, so that's reasonably accurate, it's not the 5S tach). More importantly, it shakes the whole car, the rear end is up on jacks so maybe that's part of the problem but I don't think it should be idling either that low or that rough. It's a JDM motor that I ordered from Canada so it doesn't have the EGR stuff, I blocked any of those hose connections. As mentioned I don't have the throttle cable hooked up but I'm thinking I shouldn't need that to test for a good idle. There are no fuel leaks that I can find but after running the car (I only run for about 5-7 seconds at a pop with no coolant) I do smell gas, but maybe that's normal with no exhaust on especially after the engine hasn't been run in years from when it was sitting in Canada.
I tried to search and read other posts but no luck. Thanks for any ideas of what to check or look for.

[Garbe]

First thing to check is that you have the leads on correctly.

[Rdubs]

Thanks Garbe, sorry what do you mean by the leads? You mean the wiring or earthing connections? Thanks!

[Jiff Lemon]

he means the spark plug leads.

[Rdubs]

I'll double check the spark plug leads but pretty sure those are done right.
From reading tons of posts, it looks like common problems that might cause a low and rough idle could be:
1) AFM
2) Idle air / speed control valve (IAC)
3) Grounding of the coil/ignitor pack (right now mine is not bolted to anything, but it also has a grounding wire per the diagrams (SEE EDIT))
4) Timing (haven't checked the timing yet but doubt that's it, I haven't touched it)
5) ECU - I am using an automatic transmission ECU from a Camry, I read sometimes those cause problems but others say there should be no difference between that a Manual trans at idle
6) Spark - I'll hook a timing light up to each wire and make sure it flashes, unless someone knows a better way to check.

I also heard you can increase the idle speed using a throttle stop screw on the throttle body, maybe give it a little extra will smooth it out.
Any thoughts appreciated (assuming it isn't the spark plug leads, which I'm pretty sure it's not).
EDIT - just checked the wiring book on the grounding of coil/ignitor pack and it doens't look like anything goes to ground unless it's done through one of the two connections going into the ECU which I doubt. So maybe the pack really does get its ground from its physical bracket. I'll go find somewhere to mount the bracket but it's hard with that darn stock airbox and 5S fusebox in the way.

[Rdubs]

OK quick update, I took off the AFM and checked all resistances across terminals per the wiring book, they all check out. Second, I cleared a good earthing spot for and mounted the coil/ignitor pack to help with any potential ground problem. Put the negative cable back on the battery and tried to fire it, twice it shot to 1500 RPM then died. The third time it held around 500 RPM and I got out to check the timing. Man was that motor shaking! You can feel it but seeing it, it bounces around so much the top of the motor rocks forward and back a few inches. Maybe it's because I don't have the rear engine mount on with the crossmember off, but I doubt it looks healthy. Anyway the timing doesn't seem too far off, I couldn't get an exact measurement with it rocking so much.
So AFM and grounding of the coil/ignitor are out. Any thoughts on what else to check? I'm going to take the timing light and check to see if each spark plug wire is firing but doubt that's the problem.

[AlunJ]

The third time it held around 500 RPM and I got out to check the timing. Man was that motor shaking! You can feel it but seeing it, it bounces around so much the top of the motor rocks forward and back a few inches

Check the ignition cables are on the right cylinders, if they're all on correctly try checking the resistance of each of the cables and look for one with a differing resistance to the others.

[Rdubs]

Thanks Alun I will do that right away. Full disclosure, I don't believe I changed the spark plug wires from the ones that came with the motor from Canada. I will measure the resistance of each one and post the result. I've read a wide range of what the resistance is supposed to be, one place says it's supposed to be 10,000-15,000 ohms per foot, others say in the range of 10 ohms per foot.
One other thought, I'd imagine when the engine is cold shouldn't it idle high for a minute or two until the temp warms up? I don't have any coolant in but the temp sensor should still recognize that as a cold engine and result in the cold idle speed kicking in?

[Garbe]

You really should finish the.install properly and new oil, plugs, etc before trying fault find. It may well be the engine.just needs hooking up first.