When cranking the engine, I'm getting no voltage at my injectors. Looking at the Regina diagram, I'm wondering what could be interrupting it.

 

ok, well the power to the injectors on a 93 Regina goes....

battery +, red wire to 'radio suppression relay' pin 4. pin 3 of the RP relay is green-red through connector C55 pin 6 to the injectors. other side of the injectors goes to connector C55 pin 7 to ECU pin 18 which pulses it to ground to fire the injectors.

connector C55 is an 8 pin (2x4) connector behind the right wheel housing.

the Radio Suppression Relay coil pin 1 is black to ground, and pin 2 is blue-yellow to pin 9 of the ECU and pin 87/1 of the fuel injection/pump relay in the main relay panel behind the ashtray.

so. pull the Radio Suppression relay. Verify there's voltage on pin 4 of the socket (always on, unfused, direct from battery). Check for voltage on pin 2 when the ignition is on. if there IS voltage there, then I suspect that radio suppression relay is bad. if there isn't voltage on pin 2, I'd suspect the main FI relay (often called fuel pump relay, but its more than that). if that main fuel pump relay is NOT a 'Stribel' (white, the logo is a small circle with an S and two curved lines like )( through the S), I'd get one, other brands are junk. Its the leftmost relay in the middle row, just aft of the big round can that's in the forward/left position. Fuel Pump Relay 240 700 900

btw, either of those relays /could/ be bad, and the car might still start with starter fluid because the vibration of actually starting would unstick the bad relay.

 

I'm getting my constant 12 volts at the Radio Suppression Relay. When my ignition is on, I'm getting 12 at pin 2. I read that to bypass the relay, you jump pins 1 and 3. I did this and still no go.

 

wait. to bypass the radio suppression relay, you'd jumper pins 3 and 4, not 1 and 3.

connecting pin 1 to pin 3 would have just grounded the injectors, which wouldn't do anything.

pin 4 is direct-from-battery always-on power, and pin 3 goes to the injectors. pin 1 of the relay is ground, pin 2 is the signal from the main relay, when its +12, that turns the suppression relay on, so that it connects pins 4 (battery power) to pin 3 (the injectors).


(edit.. fixed above, I madea booboo about blowing a fuse).

DO check fuse 1, btw, thats power for the whole EFI control system

 

Sorry, i got my numbers mixed up. It was pins 3 and 4 that i jumpered, and my number 1 fuse is good

 

so when you jumpered 3 to 4, you still didn't have power at the injectors?

 

It turns out my meter was set wrong. I'm getting a steady 12v at the injectors during a no-start. Going off of the Regina diagram (http://repairguide.autozone.com/znet...528008c668.gif), here's what i feel is eliminated:

Radio Suppression Relay (tested and bypassed)
Fuel Injection/Pump Relay (tested and bypassed)
Cold Start Valve
Fuel Pressure Regulator (Replaced)
Coolant Temperature Sensor (Tested resistance, Bypassed with a 6k resistor)

There's the pressure sensor, which i believe is only used on the Regina systems. I can't find much info on them, but it's one of the few things that i think i've left unturned.

 

Aka, the MAP sensor

 

ok, another test. get a 12V test lamp or something, and unplug an injector, and hook the light up across the wires to the injector plug. crank car, light should pulse

have you confirmed you have fuel pressure ?

when you get one of these no-starts, crank it a few times, then pull a spark plug out, sniff it, is it damp with gasoline, or bone dry?

have you confirmed you have spark? take said spark plug that you pulled out, plug it back into the wire, hold the metal side of the spark plug against a valve cover bolt or something, and have a friend crank for a few seconds.... do you see spark ... spark ... spark ?

 

"have you confirmed you have fuel pressure ?"

I pulled the fuel line off of the back of the pressure regulator during a no-start, and got nothing. I'm assuming that means i have no fuel pressure?

 

the skinny tube on the end of the FPR is a vacuum line, not a fuel line.

the fuel return line comes off the bottom of it, and is held on with a nut. not a good idea to disconnect that and crank, as quite a lot of fuel will come blasting out of the regulator downwards when the pump is powered.

hmm. I might be inclined to slip a thin wire around one leg of fuse 11 (thats the fuel pump fuse), and run a small 12V lightbulb or LED(*) from that wire to a ground nearby (cigar lighter socket is right there), crank and verify the light comes on when you have your no-start. if you DONT get power there while cranking, its back to the fuel pump relay.


(*) if this is a naked plain LED, you'll need a ~2K ohm resistor in series with it to limit the current, and any LED has to be hooked up in the right direction to work.

 

It was the fuel line, and absolutely nothing came out. Not a drop.

In position II, the light comes on for a second, and then goes out. No light when cranking the engine.

 

hmmm. if the light came for a second on at key on, then the fuel pump relay and ECU is working, so if you're not getting fuel pump action when you crank, then the Regina ECU isn't seeing the timing signal from the REX ICU (Ignition Control Unit), or the ICU isn't seeing
timing pulses from the crank sensor which is behind and below the back of the cylinder head, stuck into the transmission bell (it picks up notches on the flywheel). odd that it starts with starter fluid tho (that is this car, right?) as those same timing pulses are used for spark...

I'm totally stuck here, I've never worked on Regina systems (uncommon or non-existant in California AFAIK).

 

I've replaced the MAP sensor to no avail, and now she doesn't really like to start with starter fluid either. I had my crank sensor (which i assume is the same as the RPM sensor) replaced last year. Is there a test i can do to check it?

 

Got a 232 ohm reading off of the crank sensor at the ECU. On to the next component

 

Okay, i've made some headway. I pulled the connector sleeve off of the ECU connector. Pin 20, a brown wire, had some corrosion. From what you had said before, that goes to the coil for the fuel pump relay. I just cleaned it all with DeOxit and i'm waiting for it to dry.

 

It appears that i've got it. Bad terminal on the ECU connector. I drilled a small hole in the side of the unit and ran a wire from pin 20 on the board and spliced it into the brown wire going into pin 20 on the connector. So far, so good. She's been starting right up.

Thanks for all of the assistance, guys! Without the help i'm sure i'd be a few hundred in debt to a mechanic by now.