2.3L ('83-'97) Cylinder 3 and 4 won’t fire

[gbcooper]

I have an 85 ranger 2.3 Lima with EFI. I’ve had the truck sitting for a few years so I’ve been trying to get her going again. I did a top end rebuild because I suspected leaky valve seals and resealed her. It ran like a misfire with lots of smoke beforehand but there was evidence that #3 had massive head gasket blowout when I disassembled it. I’ve put it all back together now but I can’t get #3 or #4 to fire.
I’ve checked for spark and the valves. I pulled off the injectors and put 12v to them and they worked fine. When I run the truck, it misfires bad and I know it’s those 2 cylinders because if I pull the wires off the distributor nothing happens. Any ideas? It has spark and a working injector.

My only theory is that the 2 injectors aren’t grounded or the wires are corroded at some point in the harness and shorting each other out. I have a multimeter and a wiring diagram so someone please throw me some suggestions. How do I test the injectors with multimeter? What should they read?
Also, in the back of the Haynes manual I found the diagram and it looks line #1 and #2 are grounded together while #3 and #4 aren’t. Is that the culprit? I haven’t traced the wires back yet since it’s night time here but if anyone else has had this issue or know what’s going on - please let me know.

 

[RobbieD]

I'd do a compression test first; it's not clear if you fixed the "massive blowout" on #3. Without enough compression, spark and a working injector won't fire the cylinder.

 

[gbcooper]

I'd do a compression test first; it's not clear if you fixed the "massive blowout" on #3. Without enough compression, spark and a working injector won't fire the cylinder.

What size adapter do I need? I actually have a harbor freight one but none of the adapters fit or threaded.
Also, when I had the head off I took the time to clean the surface real well. Albeit I didn’t have it machined. I let about half an inch of atf sit in each cylinder to gauge the rings and it took about 3 days to show the pistons again. I figured they’d leak differently if 1 was crud.

 

[RobbieD]

I'm not sure what size adapter you'll need.

It just makes a lot of sense to confirm the compression (as it's not difficult to do and you did have a head gasket issue), before you start chasing other things.

 

[scotts90ranger]

The spark plug threads are standard 14mm, you might need the longer adapter on there to work.

all 4 injectors are powered at all times with the key on, the computer only has two injector drivers in it that trigger cylinders 1 and 4 at the same time and cylinders 2 and 3 at the same time, IE batch fire... If you look at the turbo swap area there's a I think '91 Ranger engine wire harness drawing, the injector wiring is the same even though in '91 a Ranger had distributorless ignition and a mass air flow sensor instead of a MAP sensor.

I would check the power at injector 2 and 3 and continuity between the signal wire on those two injectors and the pin at the computer.

 

[gbcooper]

I’ll do a check when I get home just to make sure. Based on these responses and a good sleep - I doubt it’s the wires. I’ll report back with a compression test