82 is running again, but has new problems unrelated to voltage stabilizer.

[Maleficio]

Originally Posted by JhwShark

Always Hot is 30, Switched Hot is 15, I believe 31 is wired to ground not a direct to ground; the control unit gets ground from its pin 35...The relay always has 30 available for 12v and once car is on, 15 provides the juice to energize the relay passing the 12v to the injectors. The control unit gives the other part ot the signal in the proper firing order 1&5, 2&6, 3&7, 4&8.

I'm missing 9 volts.

[Maleficio]

What makes me mad is that the relay chart in my owner's manual doesn't mention anything about a separate injector relay, only mentions the fuel pump relay. So for all this week, I've been working AROUND the problem, and all I had to do was look at the relay chart provided by 928 Specialists. Another stupid thing I've done.

[JhwShark]

Which pin is giving you 3v? Are you getting 12v at Pin 87 (FI relay)?

Also, check contacts at Plug W on the CEP for clean.

Just keep asking...

[Maleficio]

Originally Posted by JhwShark

Which pin is giving you 3v? Are you getting 12v at Pin 87 (FI relay)?

Also, check contacts at Plug W on the CEP for clean.

Just keep asking...

Yes, I'm getting a solid 12 volts across 30 to 87 as I should. But the voltage that controls the coil is giving only 3 volts. I'm gonna go read again, but to a known good ground to verify.

[JhwShark]

tell us where the measurements come from...if you are losing voltage from coil 15 you may have a failing ballast resistor. I am not sure what you should read from coil 1 which comes from the Transistor Ignition unit.

[Landseer]

I think he's talking about the coil within the fuel pump relay --- that is supposed to activate the relay.

[Maleficio]

I verified that I can get solid 12 volts by jumping the coil hot to a good ground outside the CE: door hinge.

So I jumped the coil 12 volts to ground, tried to start the car hoping to energize the injectors, no joy. Same old gripe, starts, explodes five times, stalls.

I've taken the battery out and put on a charger. Will try again on Saturday, will continue to study and research.

[Maleficio]

Oops, I may have messed up again. I think I jumped the wrong socket and subsequently sent no voltage to the injectors.

I need to eat some food, think some more, and try again when I get a good charge on the battery.

[Maleficio]

Next try, I will jump the hot 12 volts straight to the injector output socket. Sheesh, I'm feeling scattered right now.

[Maleficio]

Nonetheless, at least I verified the high resistance is in the output circuit, and not a power supply problem.

Which kind of leads me to the injector ground on the passenger side head.

[Maleficio]

Now I'm gonna do some more resistance readings.

I have a nice little set of extra ground cables that came with the voltage stabilizer. I may put one or two of them to use this weekend.

[Landseer]

There are instructions for tracing these circuits buried in your manuals --- did you find it?
Don't risk burning up your electronics.


The injector relay has two 87's. Its a complex relay. You should build the three legged jumper wire and jumper it. Do you know which relay and how to jumper it? It needs 30 to 87 to 87. These relays are known to fail on one side and cause lots of problems.

[Maleficio]

Just had a good idea. I wonder if I have high resistance in the ignition switch?

I put the key in the ignition switch, rotated slowly and watched the resistance of around 70 ohms slowly reduce as I got closer to the crank position. In run/crank, I get 20 ohms. As I back away from run, where I know the car shuts off, I get slightly more than 20 ohms. So if I'm only getting 3 volts for injector power, and it goes through the ignition switch, and the switch is resisting by 20 ohms, and it only takes a little more to kill ignition, it seems to me that the switch is preventing the injectors from getting full power.

Yeah, 20 ohms seems like it shouldn't be enough to prevent the injectors from operating, but at the kill position, I'm getting just a little bit more resistance.

I read out the injector ground. At first, it gave 20 ohms, too, but with a better ground on the water bridge, I was able to get .01 ohms. So I'm thinking the injector ground is okay.....for now.

I think I have multiple small problems. I've dealt with this before on Hornets. A bunch of small imperfections all worked together to create one big, ugly gripe.

High resistance in the ignition switch, weak fuel pump (have not verified yet), degraded fuel pressure regulators and damper, and very likely, grounds that have degraded after a year of operation.

The ignition switch has given more problems the entire year, but solely in the accessories circuit. With power on, tilt steering wheel upward, lose power to the stereo, but comes back on shortly. I've reached under the pod and wiggled the switch harness, but could never duplicate. It only happens when the wheel is tilted upward to the full stop.

I have to keep reminding myself that there is an ignition control unit in between the CE and the injectors. So I focused on the power supply circuits, and was happy to see the switch rotation showed another small issue.

[Landseer]

There are a few mechanical point-type contacts inside the switches. I'm sitting here staring at one that was taken apart. They are know failure points. Shouldn't you replace that? Grounds cleaning, panel cleaning. It'll all get better like on the plane

[JhwShark]

My understanding of the FP relay...DIN
30 always hot (some have a dedicated in-line fuse on the relay) from Bat.
15 Switched Power 12v to a Transistor within the relay that steps voltage down (unsure of the v) to energize the internal coil (to the FP) closing the circuit allowing 87 to pass voltage (12v from 30) to the FP. Independent of the FI relay.

Did you replace the any/all TEMP, O2, Airflow, Throttle (2) sensors and/or confirm their values...these directly interact with the Control Unit??

[neil30076]

as Landseer said, You are running a serious risk of burning up your electronics.
How about posting a picture of the wiring diagram you are using, and showing us exactly where you are jumping, measuring the resistance, etc.

[JhwShark]

Great question..
I'm using as a reference http://www.cannell.co.uk/928_Workshop_Manuals/1982%20Current%20Flow%20diagram.pdf

[Landseer]

The alarm will interrupt it.
So will corrosion at fuse 22.
Or problems behind the panel.

The panel needs to be removed, cleaned and re-fused.
All grounds cleaned.

All the rest is futile til that's done.


Don't make me drive down there, Maleficio. ( wish I could help, but have stuff here that needs to be done this weekend)

[Maleficio]

I'm using the workshop schematics that came with the car.

[Maleficio]

Hatch alarm connection is disconnected. Was having random alarm activations.