Just picked up a nice 1987 Rx7 FC N/A. It has about 80 000Km on it, but it had been sitting in the previous owner's garage for ~7 years due to a broken fuel pump... All original, good compression, almost no rust! A/C was also mostly removed..

What Ive done so far: Swap out fuel pump for stock FD pump, Drain what I could from fuel lines, and free up the throttle linkages/ intake actuators with some WD-40.

Took a while to start up (as expected), but the whole car was shaking at low rpms (I figured its probably from old rubber sticky motor mounts), it would stumble on acceleration (not in gear, just free-revving), and it wouldn't go above 4000rpm... Also after about 10-15 mins of 1500-2000rpm, the exhaust just behind the headers was glowing slightly, so I shut it down. No check engine or other warnings that weren't supposed to be on. Figured it was dirty injectors, which made sense because of the old fuel sitting in there for so long.

Next day I lightly cleaned the injectors, checked the oil (nice and fresh) and started it up again (much easier this time, only about 5 seconds of turning it over). Still very shaky near idle (<1000 rpm), but it revved pretty well up to 7000 without too much trouble (minor hesitation at about 4500 and 6000).

Planning on: Changing spark plugs, getting spare injectors if I can find cleaner ones, flushing coolant, brake, steering, clutch fluids, etc.


Now for my questions:

Shaky motor: it is just stiff motor mounts? should I oil them or will it work itself out? new spark plugs might help? or is it something else?

OMP: I heard the pump is pretty bulletproof, but the lines don't seem to have any oil in them and I cant easily see any smoke out the exhaust. Should I prime the lines somehow? is there any way to check that the system is working? any tips would be great

Coolant temp: even after the 5-10 mins running on clean-ish injectors, the rad and coolant were still ambient temp. How long does it usually take to warm up? is there a thermostat I should check/oil?

Any other things to watch out for or check? vacuum lines/ pumps/ fluids/ electrical/ other things to check?

keep in mind the car hadn't moved or ran in ~7 years, so any number of things could be happening.

Thanks in advance!

 

An FD fuel pump could very well be overkill for an FC NA.

 

I would pull the injector and send out for cleaning. Not much money. Upper intake has to come off. Not that hard. Watch out for the Pulsation Damper. My S4 one leaked bad. Fire danger!!!

 

Ok, thanks for the tips, ill try and source a stock pump and newer/cleaner injectors. I haven't gotten deep enough into the intake to take off the primary injectors yet, but I'll get to that eventually. At the moment, the car runs decently and I added a light bit of premix to the fuel just in case the stock OMP isn't actually working/lines clogged/whatever. Got the secondary injectors cleaned pretty well with new seals and grommets on them, new plugs, and bled the brakes, coolant, and clutch...

Problem now is:

Idles very low (500~ish rpm, have to give it some throttle once it turns over the first few times, also shakes the whole engine between 500 and 900 rpm).

Starts easy enough when cold, idles low but revs ok; but as soon as its a bit warm (not even registering on the coolant temp gauge) it wont start at all...

I'm thinking its running really rich at idle? TPS should be quick to adjust using the screw near the throttle cable? then adjust idle speed with the screw on top of the TB? or could it just be a vacuum leak somewhere?

 

The car will run rich likely because of too much fuel.

 

The glowing exhaust would indicate a very rich mixture, among other things. Have you checked vacuum to verify no restrictions in the exhaust (e.g. catalytic converter)?