I just replaced my 1.7 with a 73 2.0 that has been sitting for a few years. I got it up and running yesterday but it won't idle, maybe at 200rpm's. adjusting idle speed has little effect. The engine revs easily and comes back to idle quickly.

I have all matching FI components, no vacuum leaks that I can tell.
double checked my vacuum hose routing per pelican's diagram
ECU idle mixture is set between factory mark and full rich (doesn't seem to make any difference other than smelling more fuel out of the exhaust)
Valves adjusted and timing set.
Fuel pressure is just about 30psi.
I am pulling about 20hg at 1000rpm.

The only issue I have is some popping once every minute or so out of the exhaust when letting the engine run about 2500rpm for a while.

Check out your distributor and advance plates.
Make sure the advance plates move freely.
Replace the distributor with the one from the 1.7 that you know works.
Check you dwell again...48-52...to low a number will affect idle.

Remove all hoses from the intake and block them.
Only attach the MPS.

Check the TPS setting...use the picture below for reference...your TPS may be different. They key is that there is an idle circuit in the ECU that is activated by the position of the TPS at Idle...look at the middle contact...there is a unique spot on each TPS that does the same thing.

Rich

I bought a dizzy from another lister here, replaced the point plate, checked the vacuum can (good), checked operation of the advance arms and lubed those parts. I have a pertronix in it now,

I just read another post suggesting I remove the felt and shoot some pb blaster in it, then lube with light oil, so I am doing that now.

I reset my TPS when the engine was running before, but I will do it again.

Did you swap a 2.0 MPS over as well? Does it hold a vacuum? If so, is the line to it pulling a vacuum at idle? Super quick test on the latter, pull the mps hose off and what happens? If nothing, you found the problem.

swapped MPS too, it was tested and working great before - but I will give it a shot

I thought that I did not have vacuum leaks until I sprayed some carb cleaner around the intake manifolds. I quickly found my leak.
edit
how about the CHT? some 2.0 FI requires a special resistor on the CHT.

correct CHT and 270ohm resistor

have you checked the injectors for a good spray pattern?

No, not yet.

tried disconnecting the mps and the engine dies off. I am pulling 15hg on the mps for 5 minutes and see if there is a leak.

disconnecting anything on the plenum raises the idle.

mps holds steady at 15hg

I ended up using a variable resistor to get rid of low/hunting idle. I think I ended up around 470ohms. It was pretty much the last thing I tried.

On Djet a vacuum leak causes fast idle, not slow. Don't waste time chasing that rabbit trail. The only exception is the hose to the MPS and you've already proven that's not the issue.

The timing at idle may be retarded, it may be too rich, or it's not getting enough air. Strange the air bypass screw in the throttle body doesn't do much of anything. Make sure it's letting enough air through.

it's letting air through the idle speed valve, you can hear it squeal when you really open it up.

just pulled the plugs and did a compression check 4 & 2 are at about 140psi & 1 & 3 are in the mid 120's - not bad for an engine that has sat for 3.5 years.

2 plugs are black and sooty at the tip of the threads, the other two have no coloration at all. So it looks like I need to get the injectors cleaned out as my next step.

can you pull the injectors and test fire them into glass jars?

Two plugs are sooty, two plugs have not color.....makes me wonder if your FI trigger points are dirty or not firing correctly.

Might be worth a validation before you pull the injectors to get them cleaned....it could be a loose ground for those injectors, it could be the trigger points, it could be the wiring harness..

Rich

it's 1 & 3 that are not sooty. Is it 1,3 & 2,4 for the injector points?

Think so, but I have been wrong many time before...

I would first check the injector grounds....top bolt under the plenum.

Second...get some glass baby food jars and put all four injectors in the jars...still hooked up to the car.

Remove the high voltage main coil wire from the coil to the distributor.

Turn it over (ideally have someone do this for you so you can watch)
And then see how much fuel is in each jar...

If you do all four at once...its easier to compare.

Rich

Grounds are good, I went through the harness before I put the engine in.

Just went to the store and picked up some baby food jars. Anyone need whipped lasagna?

Whipped lasagna... Mmmm tasty.
Good luck Travis.
For grins:

Awesome!

Ahem, it helps if you get the right injector leads into the right injectors. (I had one swapped) White ones in the front?

was it #4 & #3 that you crossed?

Yes, if the injector leads with a white boot goes to the front.