No injector pulse

[radeznc]

Hey Folks,
1982 124 Spider 2000 barn find.
I've been combing this forum and reading through all the no start posts and trying everything I've read.

I've verified fuel pressure.
I can get it to fire on starter fluid, spark is there.
I've verified the injector side of the dual relay.
I've traced the brown and white wire, there's not a fuse on it, PO must have removed it.
I've checked the grounds on the ecu.
I've cleaned the 2 grounds connected to the intake manifold.
I've checked the TPS sends the signal it's closed.
I've tried a 200 ohm resistor in the temp sensor wire.
My cold start valve wire turns on for 8 seconds and off.
I get a flickering test light from pin 8 when the distributor is turning.

I do know my cold start valve needs to be replaced, I've been waiting to do that until I get the injector pulse.
I just replaced all 4 injectors.

I checked injector pulse wire #1 with a noid light and with a test light. Doesn't light up.
I opened up the ECU and verified the two power transistors. They both test ok.

I have yet to check the AFM, Would that keep the injectors from pulsing?
Have I missed?
Any suggestions?
Anyone have an extra ECU I could pay for shipping to try swapping with mine to see if it's my ECU? I'm in Raleigh, NC 27606

Thanks for your time!

[radeznc]

I just remembered I forgot to mention in my first post: the battery got hooked up reverse polarity when I first got the car. The Battery connectors have been cut off and trying to get power to it at first the wires from the alligator clips to the battery terminals got crossed when they were attached.

[spider2081]

the battery got hooked up reverse polarity when I first got the car

Often the instant the reverse polarity takes place a diode shorts in the alternator. This short should cause a substantial spark when the last battery lead is connected to the battery. A diode short could quickly drain a full charged battery. The ECU is triggered from the "D" terminal of the ignition coil. The "D" terminal should have the brown/white wire for the tachometer and the yellow wire for the ECU connected to it. The yellow wire from the ECU is often inside a black plastic sleeve so it appears black until the sleeve is pulled back a bit.
Fuel pressure at the fuel rail usually means the dual relay is working. Cold start valves are not prone to inoperative failures. I think their most common issue is that they leak fuel when they are not suppose to. Do you hear or can you feel a click from the cold start valve when the key is in the start position? I check this by first removing the red push on wire from the starter solenoid. That keeps the starter from engaging and lets hearing the cold start valve click easier. The cold start valve only operates when the ignition switch is in the "start" position and the temperature is below 95F.

[Twincam]

Run 12v directly to the injectors and listen to hear if they click. If it fires on starting fluid, the injectors may be locked up from sitting.

[radeznc]

Twincam:
The injectors are brand new. The gas that came out of the rail when I first got it was bright neon yellow. I decided to just go with brand new ones.

-------
spider2081: thank you for this very detailed explanation, lots of great info!

There was an initial spark when I connected the battery. I remember that pretty clearly.
Other things I have read made me suspect the alternator would be damaged by the battery polarity reverse. Though I didn't think this would prevent the car from starting? I just suspected the car would run on battery until I got it fixed. Am I incorrect about that?

When I pull the alternator is the diode replacement a repair I can do myself? Or should I just replace the whole alternator?

I'll check the cold start valve for a click this weekend when I work on it.

Finally, the yellow wire...
My coil has, on the negative side, a black and a brown/white wire and an empty spade. One the positive side,
a pink wire and a black one underneath it. I assume this black wire is the white wire you are talking about.

I get the flickering test light when I connect my test light from pin 1 to ground, is this yellow wire the one I'm testing when I do that?

More information:
I have two wires close to the coil I've been suspicious of.
One is a white wire labeled 22. I didn't see anything in the ?brad artigue? wiring diagrams that indicated a yellow wire to the coil or what is connected to ECU pin 22. My ECU wire bundle is not color coded, the wires are all white and are numerically labeled.

The other wire I'm suspicious of is a solid green wire that is connected to what I think is an O2 sensor in the exhaust manifold. The spade connectors are both female on the sensor's wire and the 22 wire and male on the green wire.

Again, thank you for all the excellent info!
I'm really excited to get my spider to start!

[radeznc]

I just re-read your post spider2081.
I think I understood this time that the yellow wire should be on the D terminal with the brown/white wire?

So
my coil is labeled + the wireing diagrams label it B+, that should just be the pink wire?
My coil is labeled - and the wiring diagrams label it D, that should be thicker black wire, brown/white wire and yellow wire that is wrapped in black and is thinner than the other black wire?

Is this Correct?
Should I peel back the black to verify the yellow is in there?

[spider2081]

Magneti Marelli labeled the coils primary terminals + and "D" most after market coils are labeled + and - The minus and "D" terminals are the same electrically. ( point side of the coil)

Yes on the + terminal of the coil the cars pink wire should be the only wire from the cars harness connected. Their is usually a radio filter capacitor with a short black wire along with a red wire that connects to the ignition control module also connected to the + terminal.
Your - terminal should have a black wire from the ignition control module, The brown/white wire for the tachometer and the wire that connects to pin 1 of the ECU. Some cars have a second brown/white wire for this connection but most have a yellow shielded wire protected by a black vinyl sleeve for this connection. The heat sink for the coil and the ignition control module should have a heavy black wire connecting the heat sink to a stud for the cover on the back of the exhaust cam box. There should be 3 wires connected to the negative terminal. The black wire passes behind the coil into the heat sink. The other 2 are part of the cars wire harness. If you traced a wire (by itself) from the coils - terminal to pin 1 of the ECU and it is not shorted to ground that should be the correct wire regardless of color.
Hope this helps.

[radeznc]

I have verified that the wiring is in fact the way you describe it.
+ has pink, black to filter and red to ignition module
-/D has brown/white, thicker black wire that shows continuity with pin1 (the yellow wire) and a black wire that goes to the ignition control module.

Other items:
- There is a ground that runs from the body next to the coil to the valve cover on the passenger side.
- I also verified that the green wire I was unsure of show continuity with pin 24 which is an O2 sensor pin so that is correctly hooked up.
- I also unplugged the starter spade and the fan and put my ear close to the cold start valve. No Click.

Final outcome: Same result.
If it sits for a while it will fire once or twice when I turn the key, i presume from the gas pressure pushing a bit of fuel in somewhere as pressure dissipates? Then it continues to turns over without firing.

[radeznc]

Progress from the weekend.
I pulled the alternator and bench tested it.
Red lead on the positive terminal, black on the housing gets 0 ohms
Red on housing, black on positive terminal gets infinite.
This indicates the alternator should be ok?

Nothing in the cabin lit up without it, but turning the key the starter will turn.
I had another alternator that doesn't fit, but hooked it up and set it in the car so it was grounded and turned everything over and noticed a very faint flicker in the noid light.

I then cleaned the connection where the alternator connects to car and reinstalled the alternator and got the same result. noid light pulses faintly.
I tried another battery and got the same result.

unfortunately... still doesn't start.
I re-verified the dual relay. This time checked voltage on all the tests. Looks like it got 25v? on all the voltage checks? This seemed weird, but got consistent reading on all the checks on the dual relay.

I suppose another check would be to see what voltage it actually showing up at the injectors.

Anyone have other suggestions?

[spider2081]

Red lead on the positive terminal, black on the housing gets 0 ohms
Red on housing, black on positive terminal gets infinite.
This indicates the alternator should be ok?

I don't know what type of meter you are using to make our tests.
I think a digital meter would need to be on diode test for static testing an alternators diode pack
With the red lead on the alternators output post and the black lead on the alternator case the display should indicate "open"
With the black lead on the alternators output post and the red lead on the alternators case the display should show a forward biased diode.
If you look at the internal diode diagram of an alternator I think you will see why.

[radeznc]

I couldn't find my digital multimeter this past weekend so I was using a resistance test. I found my digital multimeter today and retested. The test results with the digital multimeter are as you described. Alternator tests good.

I also added another ground from my valve cover the injectors are under to the chassis. This didn't change things.

[spider2081]

Alternator tests good.

A better test of the alternator is with the engine running.
A fully charged battery should measure close to 12.6 volts DC.
A spinning alternator should produce between 13.7to 14.5 volts DC measured at the battery.
Then switch the volt meter to AC the meter should display less than 1.5 volts AC, measured at the battery or the alternators output post. (engine running above 1000 RPM) This test checks the quality of the diode block. Some digital meters do not measure real AC and can give a false high display. I found Some Harbor freight digital meters do not display this test correctly.
The above tests is best be performed both with as many electrics in the car "off" and then "on" to see the change in alternator and voltage regulator performance.

[radeznc]

I did put in a spare alternator I have. It won't bolt into place because it's not the right size but I was able to wire it to the point the car would light up inside.

So the battery wouldn't charge but the rectifier in it is good.

Car wouldn't start with the spare alternator.

[spider2081]

Car wouldn't start with the spare alternator.

That would indicate there is probably more than one issue with the car.
Power to the fuel injectors comes from the Dual relay when the ignition switch is in the "run" position and the air flow meter flap is open. (engine running or cranking)
The ground for the injector to open comes from the FI ECU. It is short duration but should be visible with a node lite.
Do you have fresh fuel in the car? Have you removed the spark plugs and inspected the electrodes condition?
Have you disconnected the fuel line from the cold start valve and pumped fuel from it into a bottle to see how it looks and smells?
Have you tested the fuel injector connectors for voltage? Do you have battery voltage in both pins with ECU plugged in and only one pin with the ECU unplugged? ( air flow meter flap open)

[radeznc]

Do you have fresh fuel in the car? Have you removed the spark plugs and inspected the electrodes condition?
Have you disconnected the fuel line from the cold start valve and pumped fuel from it into a bottle to see how it looks and smells?

Fuel lines were flushed when I replaced the injectors. Using fresh fuel.
Plugs look like they were replaced and never used by a PO.

Have you tested the fuel injector connectors for voltage? Do you have battery voltage in both pins with ECU plugged in and only one pin with the ECU unplugged? ( air flow meter flap open)

Key in run position, ECU connected, I get battery voltage on both injector #1 pins.
Key in run position, ECU disconnected I get no voltage on either injector #1 pins.

I think I read the ECU has to signal the dual relay for it to work?