1985 928 won't engage fuel pump or fuel injectors
#16
Team Owner
On your car Their are two CPS,
NOTE they are both located at the rear of the V on the engine and the bell housing.
NOTE the one closest to the radiator is the one that will be used to run the engine.
This CPS male connector is the part that crumbles so dont touch it until you have a new part to install.
The one thats closest to the driver will be used for the dealer to take an RPM reading.
IOW its not used to make the engine run.
the barrel connector for this one is bolted to the left side plenum.
Huuumm how did you determine that both of the wires going to the fuel pump go to ground?
What I would do is replace the fuel pump fuse ,
remove the fuel pump relay and then put in the jumper ,
see if the pump runs.Or put a test lamp on the hot lead of the pump and see if its getting power.
Take a battery jumper cable and put it on the negative terminal of the battery,
and then the other end goes to one of the nuts on the rear shock mounts, this to add an additional ground .
NOTE leave the original negative terminal and cable connected ,after you have cleaned all of the elex connections
NOTE they are both located at the rear of the V on the engine and the bell housing.
NOTE the one closest to the radiator is the one that will be used to run the engine.
This CPS male connector is the part that crumbles so dont touch it until you have a new part to install.
The one thats closest to the driver will be used for the dealer to take an RPM reading.
IOW its not used to make the engine run.
the barrel connector for this one is bolted to the left side plenum.
Huuumm how did you determine that both of the wires going to the fuel pump go to ground?
What I would do is replace the fuel pump fuse ,
remove the fuel pump relay and then put in the jumper ,
see if the pump runs.Or put a test lamp on the hot lead of the pump and see if its getting power.
Take a battery jumper cable and put it on the negative terminal of the battery,
and then the other end goes to one of the nuts on the rear shock mounts, this to add an additional ground .
NOTE leave the original negative terminal and cable connected ,after you have cleaned all of the elex connections
#17
Rennlist Member
Fuse/Relay diagram
In a sleeve on the wood panel that covers the CE, should be a fuse/relay chart. If it is lost, go to 928gt.com, in left column of home page, find your year, print out a fresh. Laminate it. Good luck.
#18
Rennlist Member
I learn something new every time I read one of these threads...
On your car Their are two CPS,
NOTE they are both located at the rear of the V on the engine and the bell housing.
NOTE the one closest to the radiator is the one that will be used to run the engine.
This CPS male connector is the part that crumbles so dont touch it until you have a new part to install.
The one thats closest to the driver will be used for the dealer to take an RPM reading.
IOW its not used to make the engine run.
NOTE they are both located at the rear of the V on the engine and the bell housing.
NOTE the one closest to the radiator is the one that will be used to run the engine.
This CPS male connector is the part that crumbles so dont touch it until you have a new part to install.
The one thats closest to the driver will be used for the dealer to take an RPM reading.
IOW its not used to make the engine run.
#19
On your car Their are two CPS,
NOTE they are both located at the rear of the V on the engine and the bell housing.
NOTE the one closest to the radiator is the one that will be used to run the engine.
This CPS male connector is the part that crumbles so dont touch it until you have a new part to install.
The one thats closest to the driver will be used for the dealer to take an RPM reading.
IOW its not used to make the engine run.
the barrel connector for this one is bolted to the left side plenum.
NOTE they are both located at the rear of the V on the engine and the bell housing.
NOTE the one closest to the radiator is the one that will be used to run the engine.
This CPS male connector is the part that crumbles so dont touch it until you have a new part to install.
The one thats closest to the driver will be used for the dealer to take an RPM reading.
IOW its not used to make the engine run.
the barrel connector for this one is bolted to the left side plenum.
I found a video of someone starting a 928 and yea the rpm jumps to like 3500 rpm. I think @PorKen might have found the main cause of the problem.
Huuumm how did you determine that both of the wires going to the fuel pump go to ground?
What I would do is replace the fuel pump fuse ,
remove the fuel pump relay and then put in the jumper ,
see if the pump runs.Or put a test lamp on the hot lead of the pump and see if its getting power.
remove the fuel pump relay and then put in the jumper ,
see if the pump runs.Or put a test lamp on the hot lead of the pump and see if its getting power.
Take a battery jumper cable and put it on the negative terminal of the battery,
and then the other end goes to one of the nuts on the rear shock mounts, this to add an additional ground .
NOTE leave the original negative terminal and cable connected ,after you have cleaned all of the elex connections
and then the other end goes to one of the nuts on the rear shock mounts, this to add an additional ground .
NOTE leave the original negative terminal and cable connected ,after you have cleaned all of the elex connections
#20
Rennlist Member
Duke, what is the relay part number in your car in slot XX (4th from the right on the top row)? Is it a 53 relay? I'm thinking maybe you got some crazy Autozone relay in there or something.
#21
Team Owner
if you follow the hose from the back of the fuel pump to the bottom of the fuel tank do you see wires that plug into the tank? If so you may have a shorted intank fuel pump or the fuel pump relay is closed.
Try looking for these extra wires and if none,
then remove the relay for the fuel pump, and then test these wires again.
Then remove the fuel pump fuse put in a new FP relay and fuel pump fuse
Try looking for these extra wires and if none,
then remove the relay for the fuel pump, and then test these wires again.
Then remove the fuel pump fuse put in a new FP relay and fuel pump fuse
#23
Ok I got to the car and reconnected the pump and tested with a wire where the relay goes. Pump turns on just fine. Changed the relays and of course it wouldn't start, so I decided to tackled the crank position sensor. And of course, I broke it and now it's stuck. I figure I'd try from underneath but I'm having a bitch of a time. Is there an easy way to remove the flywheel without removing the exhaust and drive shaft? Do I need to remove the flywheel to hit it from underneath to push out the sensor? Here's some photos of what I've done so far. I'm upstate NY right now so if I don't figure out something I'll have to come back next week and try again.
#24
Ok I was doing some research and yea, I don't think I wanna drop the drive shaft to remove the flywheel. Not where that car sits in that dirt filled spot. Anyway, so it looks like I'll have to dig out the remaining sensor from on top, which I wanna know if this pipe I see can be easily removed? I kinda avoided it cause it looked like an A/C line or something that went into the firewall. Cause I'm thinking of hitting it with a blowtorch and digging it out with a pick, so I'll need the room.
Another idea I have is pushing it up from underneath but I couldn't see it. Though I haven't tried to turn the engine to the point where the 2 missing teeth are right where the sensor is. I was wondering if I rotate the motor could I put a screw driver there and push it up with a jack? This is an automatic so I don't find much info on people dealing with this on automatics.
BTW, a photo of the drive shaft for reference. If this were in my driveway I'd have no problem, but it isn't.
Another idea I have is pushing it up from underneath but I couldn't see it. Though I haven't tried to turn the engine to the point where the 2 missing teeth are right where the sensor is. I was wondering if I rotate the motor could I put a screw driver there and push it up with a jack? This is an automatic so I don't find much info on people dealing with this on automatics.
BTW, a photo of the drive shaft for reference. If this were in my driveway I'd have no problem, but it isn't.
#26
As for the CPS, I figure I'll torch what's left and pick at it with a dentist like pick I have and eventually I hope I can just lift out the cylinder that's in there. Though I'd like to know what that metal line is in front of that area? Can I just disconnect it and move it away so I can have enough room for a blow torch?
#27
Chronic Tool Dropper
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Of course that's a fuel line crossing in your picture, partially blocking access and the view of the CPS. One of your several tasks with the car will include replacing the soft lines, including the U hose pictured between the rear damper and the fuel pressure regulator. Those parts have screw fittings to the fuel rails on either side, and the return line to the fuel cooler should be replaced too. Remove them now to get them out of the way, put new lines back in.The fuel rails want to come off to replace the hoses and seals and refurb the injectors.
The CPS is a sintered iron rod poking down to sit really close to the teeth on the flywheel. You'll want to remove the flywheel. You may have some luck breaking the rod and the housing apart, but there's really no place to drive them to from the to with the flywheel in place. And no good way to get the flywheel out with the gearbox and the torque tube/driveshaft in place. You can try a torch if you think it will make you feel better, but unless you have something to grab on to and pull up, you are goingto do more damage than good with that much heat there.
----
Most cars described as "ran when I parked it" really mean "ran until I parked it". Folks don't just stop driving a good car without a reason. Often that reason is related to "wouldn't start and it was easier to take the Pinto to get to work". Now that original long-forgotten reason for not starting is dwarfed by all the deterioration that's happened since. Know that a car with no major issues needs at least $5k just in rubber and related safety bits to make it safe and reasonably reliable. Fuel hoses, oil breather hoses, intake boots, brake hoses, coolant hoses, battery and cables, brakes,seals to keep the water out, suspension bits and bushings, motor and transmission mounts, CV and steering rack boots, tires, and more. HVAC actuators and AC hoses, if you want those things to work. It's real easy to get way upside down in one of these, even if the car is given to you for nothing. Keep some perspective on what you are doing. Some folks live for the challenge, and that's fine.
The CPS is a sintered iron rod poking down to sit really close to the teeth on the flywheel. You'll want to remove the flywheel. You may have some luck breaking the rod and the housing apart, but there's really no place to drive them to from the to with the flywheel in place. And no good way to get the flywheel out with the gearbox and the torque tube/driveshaft in place. You can try a torch if you think it will make you feel better, but unless you have something to grab on to and pull up, you are goingto do more damage than good with that much heat there.
----
Most cars described as "ran when I parked it" really mean "ran until I parked it". Folks don't just stop driving a good car without a reason. Often that reason is related to "wouldn't start and it was easier to take the Pinto to get to work". Now that original long-forgotten reason for not starting is dwarfed by all the deterioration that's happened since. Know that a car with no major issues needs at least $5k just in rubber and related safety bits to make it safe and reasonably reliable. Fuel hoses, oil breather hoses, intake boots, brake hoses, coolant hoses, battery and cables, brakes,seals to keep the water out, suspension bits and bushings, motor and transmission mounts, CV and steering rack boots, tires, and more. HVAC actuators and AC hoses, if you want those things to work. It's real easy to get way upside down in one of these, even if the car is given to you for nothing. Keep some perspective on what you are doing. Some folks live for the challenge, and that's fine.
#28
Rennlist Member
This link, https://www.928gt.com/t-8586fuse.aspx courtesy of 928 Specialists shows the relay position and also the Porsche part number. Relay can be obtained from any of the main 928 vendors. But the car will run fine without any relay in there.
This is one thread that shows how to deal with a stuck CPS - there are other similar threads as well. https://rennlist.com/forums/928-foru...s-removal.html
This is one thread that shows how to deal with a stuck CPS - there are other similar threads as well. https://rennlist.com/forums/928-foru...s-removal.html
I've read threads about that kickdown relay. You can barely see it int he photo but someone who is a self proclaimed Porsche expert had removed the relay box for another box to fix this issue. So I'll have to check to see what relay was used in there. My question is what relay should go in there? I've searched around and it seems impossible to find a replacement relay.
As for the CPS, I figure I'll torch what's left and pick at it with a dentist like pick I have and eventually I hope I can just lift out the cylinder that's in there. Though I'd like to know what that metal line is in front of that area? Can I just disconnect it and move it away so I can have enough room for a blow torch?
As for the CPS, I figure I'll torch what's left and pick at it with a dentist like pick I have and eventually I hope I can just lift out the cylinder that's in there. Though I'd like to know what that metal line is in front of that area? Can I just disconnect it and move it away so I can have enough room for a blow torch?
#29
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This link, https://www.928gt.com/t-8586fuse.aspx courtesy of 928 Specialists shows the relay position and also the Porsche part number. Relay can be obtained from any of the main 928 vendors.
Hope you are well, all my best to you!
You may be wrong about that above statement, if you look at the relays on my website and then buy somewhere else.... they will not be compatible and cause all sorts of electrical issues.
JUST KIDDING!! :-)
Happy Sunday,
Dave
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David Roberts
2010 Jaguar XKR Coupe - 510HP Stock - Liquid Silver Metallic
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#30
Rennlist Member
Duke,
You can also drive the CPS past the flywheel and let it drop out the bottom. When it's touching the flywheel, just move the tip of the CPS toward the back of the car and hit it carefully from above with a punch. Don't damage the CPS housing.
You can also drive the CPS past the flywheel and let it drop out the bottom. When it's touching the flywheel, just move the tip of the CPS toward the back of the car and hit it carefully from above with a punch. Don't damage the CPS housing.
Last edited by soontobered84; 06-25-2018 at 02:35 PM.