1985 928 won't engage fuel pump or fuel injectors
#76
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#77
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This is going to sound nutty, but it has worked for some (a few?) people in the past when it seems like everything else is connected fine. If you replaced the CPS and the tach still doesn't bounce while cranking, either the wiring is damaged between the CPS and the EZK (ignition computer) or the tach is shorted to ground.
One quirk of the 928 electrical system is that the signal to the tach and the EZK are on the same lead. If the tach is shorted, all the current goes that way and none goes to the computer. The ignition system doesn't think the engine is turning, so none of the relays are energized.
I **** you not, people have cut the wire to the tach and their non-starting 928s have started.
One quirk of the 928 electrical system is that the signal to the tach and the EZK are on the same lead. If the tach is shorted, all the current goes that way and none goes to the computer. The ignition system doesn't think the engine is turning, so none of the relays are energized.
I **** you not, people have cut the wire to the tach and their non-starting 928s have started.
Anyway, some of the relays aren't meant to be there I've found. One is a BOSCH 0332015013, which was being used in a spot that's suppose to have a 53 relay. The Headlamp wash relay was just a regular 53 relay, so I ordered the correct 928.618.111.00 relay. Now the problem I have is the kick-down relay, cause that doesn't look correct, but I'm not sure. I'm certain it was replaced relatively recently since the pins aren't corroded to hell like the rest. The relay in there now is a Potter & Brumfield VF4-15f11-722. What's suppose to be in there is the 928.618.109.00 relay, which I can't find anywhere. What's the correct relay there for a 928 with an automatic transmission?
![](https://cdn.shopify.com/s/files/1/0027/5402/products/DSC_270_large.jpg?v=1355251841)
#78
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Nah the issue is definitely the bad wiring done to the fuse panel. I've got the car to start if I jump the EZF and Fuel Pump relays. I'll know for sure once I put the fuse panel back in and give it a crank. The cleaning and polishing I'm doing to it is just a bonus.
Anyway, some of the relays aren't meant to be there I've found. One is a BOSCH 0332015013, which was being used in a spot that's suppose to have a 53 relay. The Headlamp wash relay was just a regular 53 relay, so I ordered the correct 928.618.111.00 relay. Now the problem I have is the kick-down relay, cause that doesn't look correct, but I'm not sure. I'm certain it was replaced relatively recently since the pins aren't corroded to hell like the rest. The relay in there now is a Potter & Brumfield VF4-15f11-722. What's suppose to be in there is the 928.618.109.00 relay, which I can't find anywhere. What's the correct relay there for a 928 with an automatic transmission?
![](https://cdn.shopify.com/s/files/1/0027/5402/products/DSC_270_large.jpg?v=1355251841)
Anyway, some of the relays aren't meant to be there I've found. One is a BOSCH 0332015013, which was being used in a spot that's suppose to have a 53 relay. The Headlamp wash relay was just a regular 53 relay, so I ordered the correct 928.618.111.00 relay. Now the problem I have is the kick-down relay, cause that doesn't look correct, but I'm not sure. I'm certain it was replaced relatively recently since the pins aren't corroded to hell like the rest. The relay in there now is a Potter & Brumfield VF4-15f11-722. What's suppose to be in there is the 928.618.109.00 relay, which I can't find anywhere. What's the correct relay there for a 928 with an automatic transmission?
![](https://cdn.shopify.com/s/files/1/0027/5402/products/DSC_270_large.jpg?v=1355251841)
928 International has diagrams of the fuse panel and a list of the relays, as does 928gt.com
http://www.928intl.com/repair/Relay/earlyrelay2.htm
https://www.928gt.com/
Last edited by Shark2626; 08-01-2019 at 10:31 AM.
#80
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as I understand it you can and probably should just leave the kickdown relay out for now, you don’t need it to start the car, but an incorrect one will disable starting the car.
928 International has diagrams of the fuse panel and a list of the relays, as does 928gt.com
http://www.928intl.com/repair/Relay/earlyrelay2.htm
https://www.928gt.com/
Not a lot here is mentioned in the diagram. It doesn't even show that A22 goes to the fuses 1-5, which is powered by "X" according to the diagram. What is "X" you say? Well it's the "X-Bus (+12v when accessory or ignition (2) is on, off for starter (3) position)". But fuses 6-15 are connected to the "15" wire, which yes is the "Ignition (+12v when ignition (2) is switched on, stays on in starter (3) position)". I need someone to tell me what is the difference between the two, and maybe if someone happens to have a photo of the back of their fuse panel as that would be a big help.
![](https://cimg1.ibsrv.net/gimg/rennlist.com-vbulletin/2000x1504/fuse_panel_cricled_755cd457e055cd6fa4f59da57b470a23f678910e.jpg)
Last edited by dukenukemx; 09-11-2018 at 03:10 PM.
#81
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google the part number of that Bosch relay that you want to put in the kickdown spot to see what it corresponds to.
attached is an image of the correct relay, although a later version, i think I’ve read that they are interchangeable, this is just the next generation.
but again, you don’t need that relay in the panel at the moment.
Last edited by Shark2626; 08-01-2019 at 10:30 AM.
#82
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it’s your call, but many have said that if the wrong relay (a 53 for example) is in the kickdown spot the car will not start, and this relay is not necessary for the car to start anyway. i would leave it out, for now.
google the part number of that Bosch relay that you want to put in the kickdown spot to see what it corresponds to.
attached is an image of the correct relay, although a later version, i think I’ve read that they are interchangeable, this is just the next generation.
but again, you don’t need that relay in the panel at the moment.
#83
#84
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You can see I fixed that in the photo, with the bottom panel being the new fixed panel. Also the wire that jumps the fuses 6-10 and 11-15 wasn't conducting as well as it should be. My multimeter was measuring something like 50 ohms, which is why it's red now cause I made a new one. Also I saw some wires in the original that weren't in the new one, Like two wires going from "H" to "V" that doesn't show up in the diagram. Also one that goes from "H" to "N" that doesn't show up. I removed them from the original cause I was going to put them in the new panel, but I figured if the diagram doesn't show it, why bother? Then I realized the diagram isn't accurate, and now I regret not putting them in. Can anyone give me a photo of the back of one of these panels? I just wanna confirm this.
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#85
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Just one more thing to think about on this. When you jumped the relays and the car ran, you had no tach. The tach signal and the signal that triggers the important relays to close is one and the same.
Focus on that bit of wiring.
Focus on that bit of wiring.
#86
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that’s pretty interesting. how would you go about it though?
Last edited by Shark2626; 08-01-2019 at 10:29 AM.
#87
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#88
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And to answer the questions you're actually asking, I've got an '86 panel in the spares. '86 has the same wiring as '85 for blocks N and V, which is nothing except a wire on V11. Can confirm that N and V blocks match wiring diagram.
#89
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it’s your call, but many have said that if the wrong relay (a 53 for example) is in the kickdown spot the car will not start, and this relay is not necessary for the car to start anyway. i would leave it out, for now.
google the part number of that Bosch relay that you want to put in the kickdown spot to see what it corresponds to.
attached is an image of the correct relay, although a later version, i think I’ve read that they are interchangeable, this is just the next generation.
but again, you don’t need that relay in the panel at the moment.
![](https://www.ebay.co.uk/itm/Porsche-928-Kick-Down-Relay-92861810900-/401409151597)
google the part number of that Bosch relay that you want to put in the kickdown spot to see what it corresponds to.
attached is an image of the correct relay, although a later version, i think I’ve read that they are interchangeable, this is just the next generation.
but again, you don’t need that relay in the panel at the moment.
Also the tachometer works now. Might have to do with me dunking the entire fuse panel into white vinegar along with salt to remove the corrosion on the copper contacts. Only needed a half hour of soaking and then I hosed it off and then drenched it with WD40 to prevent a flash rust. Unfortunately none of the other gauges work, like the battery, oil, and temperature. I know the fuel doesn't work, cause I saw the metal contacts in the back to be rusty. Oh yea wipers and door windows don't work either. Might be wishful thinking that removing the copper oxide got the tach working.
**EDIT**
Can anyone confirm that the 928.618.109.01 relay can but used in place of the 928.618.109.00 relay? I can't find the 928.618.109.00 so I got the 928.618.109.01 but that has a diode in the diagram connecting pint 31 & 87a. Is that ok?
Last edited by dukenukemx; 09-15-2018 at 01:01 AM.
#90
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I know I quoted you already for this post, but this was a big help. I put the repaired fuse/relay panel back into the car and it wouldn't start. After checking and looking around, I remembered about the kickdown relay, and removed it. Now it starts just fine. I already ordered and received the 928.618.109.01 relay but it didn't come until I came back from the car. Car starts just fine and moves fowards and backwards without issue. Not sure what this kickdown relay does but without it the car does run. Next time I'll put the correct relay in and see what happens. Whoever worked on this car before must have put this relay in and did a bunch of bypassing of wiring to get the car to start, not realizing an incorrect relay will prevent it from starting.
Also the tachometer works now. Might have to do with me dunking the entire fuse panel into white vinegar along with salt to remove the corrosion on the copper contacts. Only needed a half hour of soaking and then I hosed it off and then drenched it with WD40 to prevent a flash rust. Unfortunately none of the other gauges work, like the battery, oil, and temperature. I know the fuel doesn't work, cause I saw the metal contacts in the back to be rusty. Oh yea wipers and door windows don't work either. Might be wishful thinking that removing the copper oxide got the tach working.
**EDIT**
Can anyone confirm that the 928.618.109.01 relay can but used in place of the 928.618.109.00 relay? I can't find the 928.618.109.00 so I got the 928.618.109.01 but that has a diode in the diagram connecting pint 31 & 87a. Is that ok?
![](https://www.ebay.co.uk/itm/Porsche-928-Kick-Down-Relay-92861810900-/401409151597a)
Also the tachometer works now. Might have to do with me dunking the entire fuse panel into white vinegar along with salt to remove the corrosion on the copper contacts. Only needed a half hour of soaking and then I hosed it off and then drenched it with WD40 to prevent a flash rust. Unfortunately none of the other gauges work, like the battery, oil, and temperature. I know the fuel doesn't work, cause I saw the metal contacts in the back to be rusty. Oh yea wipers and door windows don't work either. Might be wishful thinking that removing the copper oxide got the tach working.
**EDIT**
Can anyone confirm that the 928.618.109.01 relay can but used in place of the 928.618.109.00 relay? I can't find the 928.618.109.00 so I got the 928.618.109.01 but that has a diode in the diagram connecting pint 31 & 87a. Is that ok?
With regards to the relay, again I only have a basic understanding, but the last two numbers generally indicate a newer version of the original, so theoretically an 01 should be a compatible replacement for an 00.
If I am wrong about any of that I’m sure someone will add the appropriate correction.
Last edited by Shark2626; 08-01-2019 at 10:26 AM.