No power to injectors

[Godfath]

No power to injectorswill start when you pour full in but stops when full is gone new full pump injectors will not open no power

[Landseer]

Oh, your the guy with the 89 964, right? You want the 911 forum.

[Godfath]

No I have a 1980 928

[Landseer]

OK. Cool.

When was the last time you cleaned the ground terminals on the car, there are about 10 or so scattered through-out, some of which operate your fuel pump and fuel injection system?

When did you last service / change any of the relays at the CE panel? Specifically relay number XVI, which sends power to your fuel injection system?

Have you ever changed-out the electrical portion of the ignition switch?

Can you post pictures of A) engine compartment and B) CE panel showing relays / fuses?

Do you have any wiring diagrams, or, the fuse panel diagram from the owners manual handy?


BTW, I've had an old fuel pump jam. Replace it, including inlet in-tank screen. Then new one jammed.

So be sure you hear the running fuel pump (also driven by a relay and a fuse) before concluding its the injector circuit./

[Godfath]

I found that their is 16v going to the plus side but nothing to the ground going to the injectors

[Godfath]

I have a bad gerund going to the injectors I got 16 v on th plus side

[MPDano]

Originally Posted by Godfath

I have a bad gerund going to the injectors I got 16 v on th plus side

Which side is bad. My Pass side wasn't getting power when I realized I had unhooked both grounds on the Cam Cover when I removed the Diverter Valve and Tube in that area. Hooked both back up and BAMMMMM, El Starto El Carro!

[Landseer]

Yes, two grounds on the passenger side cam cover, rearmost one buried under the emissions control piping.

Clean and tighten, also, positive little wires on battery as they power the brain.

If it doesnt work, the relay is next suspect.
You can use a three-way jumper after removing the fuel injection relay ( 30 to 87 to 87 ).
Check 928 specialist site, relay diag for your year, to be sure, but I think its the one noted above)

Again, be sure you detect fuel pump running, its relay can be jumpered 30 to 87...will then pump and recirc continuously without the key. Jam sometimes gives hum, but no motor.

You can also disconnect brain plug in pass compart. Then pull one injector plug. Should not read continuity across those two terminals ( no key, no jumpers in place btw). If it reads continuity, then chances are one of the injector plugs is shorted under the boot, and it affects all, reading a short at each effectively.

Good luck. Be careful in there.

[aluminum]

I agree with Landseer on the realy
Carefully remove it ( Fuel Injection Relay ) look up a fuse chart if you don't know what relay is what . Then pull it off the circuit board. ( Pass side floor area ) You may encounter broken or eroded Relay Posts > look for green corroded deposits > if you see such pull down the circuit board and remove the wires from the back side to clean off corroded deposits to that relay and any other "corroded deposits " you may see.
*************************************************
Beyond that: check out the ICU Box >> Pass Side fender well under heater hose by top Rad> Hose > clean the pins > try it >> no go> remove and open the Box inspect and clean it >> I have used Starting fluid > spray it then blow it off compressed air and dry it > done this many times with no problems Note: it is normal to smell a electric smell when you open the box.

[aluminum]

I agree with Landseer on the realy
Carefully remove it ( Fuel Injection Relay ) look up a fuse chart if you don't know what relay is what . Then pull it off the circuit board. ( Pass side floor area ) You may encounter broken or eroded Relay Posts > look for green corroded deposits > if you see such pull down the circuit board and remove the wires from the back side to clean off corroded deposits to that relay and any other "corroded deposits " you may see.
*************************************************
Beyond that: check out the ICU Box >> Pass Side fender well under heater hose by top Rad> Hose > clean the pins > try it >> no go> remove and open the Box inspect and clean it >> I have used Starting fluid > spray it then blow it off compressed air and dry it > done this many times with no problems Note: it is normal to smell a electric smell when you open the box.

[nuts4porsche]

my 80' had the same problem, your injectors are not pulsing to ground,its your grounds,they need cleaned! i cleaned mine and fixed the relay/fuse panel and the car started right up!