Any advice before start a 928 in three years?
04-11-2011, 12:38 PM
#61
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Thread Starter
Thanks for your answers. I see that the main point is to check first if there is fuel and if there is spark to focus then on the problem. Sorry for the obvious questions but...
James, how do I know if the ignition rotor is turning?. It's inside the distributor right?. I post a pet diagram below to better understand your instructions for checking that.
rotaryboots, about fuel no problem, just crank, remove the spark and check if it is wet with fuel. No problem.
To test the sparks if I understand correctly, I should (first remove the fuel pump relay XVII) and then remove a spark, plug it into the coil wire and crank to see if there is spark. I have found this video (first method) that I think is similiar of what you comment:
http://www.youtube.com/watch?v=drSep...eature=related
...he ground the threaded part of the plug to a metal part of the engine before cranking, I should do that also right?.
I want to ask you something about this method. Because I used oil (fogging) in the spark wells, could that have fooled the spark plugs and make them not able to spark?. If the answer is yes, is there something I could try (clean?) to get a better scenery in future cranks?.
Nobody mention the battery, so I think that the one used could have been enough to start the car. In any case I will buy a new 85ah-800CCA of a good brand before doing new tests.
(ok about cranking just for 5-10 seconds).
About the compression test, well, first I will try the easy fuel/spark tests if both are ok, we will keep going...
James, how do I know if the ignition rotor is turning?. It's inside the distributor right?. I post a pet diagram below to better understand your instructions for checking that.
rotaryboots, about fuel no problem, just crank, remove the spark and check if it is wet with fuel. No problem.
To test the sparks if I understand correctly, I should (first remove the fuel pump relay XVII) and then remove a spark, plug it into the coil wire and crank to see if there is spark. I have found this video (first method) that I think is similiar of what you comment:
http://www.youtube.com/watch?v=drSep...eature=related
...he ground the threaded part of the plug to a metal part of the engine before cranking, I should do that also right?.
I want to ask you something about this method. Because I used oil (fogging) in the spark wells, could that have fooled the spark plugs and make them not able to spark?. If the answer is yes, is there something I could try (clean?) to get a better scenery in future cranks?.
Nobody mention the battery, so I think that the one used could have been enough to start the car. In any case I will buy a new 85ah-800CCA of a good brand before doing new tests.
(ok about cranking just for 5-10 seconds).
About the compression test, well, first I will try the easy fuel/spark tests if both are ok, we will keep going...
04-11-2011, 02:04 PM
#62
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Yes, pull the fuel pump solenoid out, then take a spark plug out, connect it to a plug wire, then crank and see if the plug sparks. If it doesn't, take the cap off the distributor and check to see if #8 spins when you crank.
A better place to test the spark is from the plug wire that goes to the center pole on the distributor cap. That wire goes to the coil, which is the main origin of the spark anyways. If you don't get any spark there, then you can focus on the parts leading to the coil, or the coil itself.
A better place to test the spark is from the plug wire that goes to the center pole on the distributor cap. That wire goes to the coil, which is the main origin of the spark anyways. If you don't get any spark there, then you can focus on the parts leading to the coil, or the coil itself.
04-11-2011, 02:28 PM
#63
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The cap is held in place by the two L shaped "bolts" You push down and rotate to release. Your diagram shows one side just above #8. move the cap out of the way and have someone crank the engine for a moment just to be sure it is turning. If it is not turning the T-belt has failed and you have no compression since the valves are not opening and closing. That would explain the rather fast cranking of the engine and why the engine does not fire. If it is turning then put the cap back on and then look for spark you can use one of your old sparkplugs just be careful not to get shocked it is a rather high energy spark on the 928. Starting fluid is a little too explosive in my opinion and I prefer using Carb cleaner spray which will fire but not explode so easily.
04-11-2011, 02:29 PM
#64
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Ok understood... I will test the spark plugs with the main coil wire. If they are not working I will check the rotor, as James said about the fast crank, and that way we will go back the line to see where the problem could be located.
As soon as I do the tests, I will post them here. The car have been all this time in a garage away from bad weather and runs before beeing parked, so I have confidence that the problem will not be huge.
Thanks a lot!.
ps.- James I read your message too about the rotor. I will be checking that too. I will be careful in the process with sparks. I know a lot of energy down there.
As soon as I do the tests, I will post them here. The car have been all this time in a garage away from bad weather and runs before beeing parked, so I have confidence that the problem will not be huge.
Thanks a lot!.
ps.- James I read your message too about the rotor. I will be checking that too. I will be careful in the process with sparks. I know a lot of energy down there.
04-12-2011, 02:48 AM
#65
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Also, the cap doesn't need to be on in order to test for spark using the plug wire from the coil.
Stupid question but I wanna ask, the green wire from the distributor got plugged back in right?
Stupid question but I wanna ask, the green wire from the distributor got plugged back in right?
04-12-2011, 05:12 AM
#66
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Ok, good to know, that probably easy the process. The bad part is having to wait from one weekend to the next to check things, but as Landseer told me... patience is my strong suit 
About the green wire... yes I plugged it back in. That's one of the things that I've thought that could be bad. Somebody told me is a common failure. I check the price with Roger and it's around 120$ plus shipping, so I will see if I can check it better (more deeply than a visual inspection). In any case is one of the things in the buying list and after the failed starts has climbed some positions in this list.
About the green wire... yes I plugged it back in. That's one of the things that I've thought that could be bad. Somebody told me is a common failure. I check the price with Roger and it's around 120$ plus shipping, so I will see if I can check it better (more deeply than a visual inspection). In any case is one of the things in the buying list and after the failed starts has climbed some positions in this list.
04-12-2011, 06:47 AM
#67
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I wouldn't check spark while holding the plug with pliers, insulated or not.
There is enough power in the spark system on these particular cars to stop your heart.
You can buy an inexpensive insert that is put in-line. It lights up with spark.
http://www.toolfetch.com/Category/Au...s/LIS20610.htm
There is enough power in the spark system on these particular cars to stop your heart.
You can buy an inexpensive insert that is put in-line. It lights up with spark.
http://www.toolfetch.com/Category/Au...s/LIS20610.htm
04-12-2011, 06:59 AM
#69
Rennlist Member
Been away for the weekend and I see you're getting there 
It must be frustrating having to wait to work on the car at weekends, but as Chris (Landseer) has observed, patience is definitely your strong suit ... I admire your persistence and determination to get everything right. As you're taking this step by step and eliminating possibilities one by one, it's only a matter of time and you'll have it fired up.
Even though green wires are often the culprit with ignition problems, don't go replacing it unless you're sure it's failed (I'm sure there are other things you could spend $120 on). Do the tests and checks that everyone else has listed and you should be able to fairly quickly determine if its fuel or spark related ... you'd be unlucky, but of course it could be both.
As Chris noted, make your starter runs reasonably short, so that you don't overheat the starter.
I'll do some resistance and other checks on my good green wire and post the results, together with some photos, before the weekend.
It must be frustrating having to wait to work on the car at weekends, but as Chris (Landseer) has observed, patience is definitely your strong suit ... I admire your persistence and determination to get everything right. As you're taking this step by step and eliminating possibilities one by one, it's only a matter of time and you'll have it fired up.
Even though green wires are often the culprit with ignition problems, don't go replacing it unless you're sure it's failed (I'm sure there are other things you could spend $120 on). Do the tests and checks that everyone else has listed and you should be able to fairly quickly determine if its fuel or spark related ... you'd be unlucky, but of course it could be both.
As Chris noted, make your starter runs reasonably short, so that you don't overheat the starter.
I'll do some resistance and other checks on my good green wire and post the results, together with some photos, before the weekend.
04-12-2011, 07:36 AM
#70
Instructor
Thread Starter
Dave, I was sure you were away for some reason not seeing your messages on the thread .
Not very frustrating, I must say I'm really having fun. Now I'm glad when something fails...
...buying a '95 928 and just driving it?... naahh, thats boring...
I'll keep short on cranks. About the resistance tests of the green wire that will be great. I have things to check before so don't worry if you can't do it before this weekend. I will try also to check the green cable with the meter on my side to compare later.
Thanks!.
.Not very frustrating, I must say I'm really having fun. Now I'm glad when something fails...
...buying a '95 928 and just driving it?... naahh, thats boring...
I'll keep short on cranks. About the resistance tests of the green wire that will be great. I have things to check before so don't worry if you can't do it before this weekend. I will try also to check the green cable with the meter on my side to compare later.
Thanks!.
04-17-2011, 09:34 AM
#72
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Thread Starter
Next episode 
. Yesterday morning some hours checking, fuel or spark, or both. Conclusion, for sure, one problem is no fuel traveling.
First we check for spark. I bought one of this:
...the one Landseer told me, sure it was better, but I haven't had time to get one of those. Also a new Varta battery with 830 CCA's is comming on monday.
We checked, on the coil wire... the light flashes ok. The pen needs to be in a darker environment for you to be able to see the light flashing (sometimes it's hard to see). The coil wire zone was easy to darken but when checking the spark wire #1 it was more difficult to see so we decide to remove one spark, hold it with a piece of wood over the engine and grounded to the unpainted part of the crossing bar. In the video you can see one or two sparks at the beginning of the crank. It is spark plug wire #1:
http://www.youtube.com/watch?v=3Y8W6loKDPE
Better than the video, I can tell you as a reference that in a 5 second cranking I see about 5 or 6 separate spark flashes. Dont know if thats good or not. But I think that if there is sparks this should mean that the distributor rotor is spinning, right?. James Bailey has doubts about the rotor, don't know if this clear the picture.
Then we checked for fuel. The easy way, clean a spark, tighten, 5 seconds crank, remove the spark and see/smell. It doesn't smell gasoline.
Then go back to the fuel pump. One question here, does the fuel pump should work just turning key to the right to the 'pre-crank' position? (where just the lights at the console turn on). We thought it should because just turning the key we can hear some flow inside the pump. In other thread today I have read that the pump only works when cranking or jumpering 30-87 terminals. So now I'm not sure if the pump should have moved yesterday just by turning the key.
In this video you can see the pump (the key just turned to the right). It does the same as the other day when jumpering 30-87. Almost no sound from the pump (if you pump up the volume you can hear some glop-glop-glop sound inside the pump when the camera gets really close to the pump).
http://www.youtube.com/watch?v=EIHbnNs44Ag
Another symptom to be worried with the pump..., if you let it some minutes like that, the pump starts getting hot. I mean that if you put your finger on the pump you have to take it out fast. I think that's not good. It is gasoline and I think it shouldn't get that hot. Of course we have been very careful monitoring that.
I will wait your answers of what you think about the health of this pump.
And in third place, what we think is some creative plumbing. We have detected on the fuel line (to the left, under the air intakes) a hose with what looks like a 'non-return valve' (or antiflow back valve) don't know how is called... that we think it is not factory. And dont know the reason why that is there. Any suggestion about what it is and why is there for?
---
A video of this hose:
http://www.youtube.com/watch?v=uXlvymVFEUM
---
We removed the hose and valve just to be sure of what it is. As Lauren Bacall said, if you put your lips together on the hose and blow, it let the air flow just in one direction of the tube, and that's what it does so as said seems a non-return valve:
http://www.youtube.com/watch?v=QPZQ4AOHD4U
---
---
Here is a transparent hose we connected to the fuel line just to check if there is some fuel flow. We just turn the key to the mentioned pre-crank position... fluids sound inside the pump, gets hot after some minutes, not even a drop on the transparent hose. We turn off the key. Maybe we should have jumper the 30-87 terminals (after reading other threads today) but I think the symptoms would have been the same described.
http://www.youtube.com/watch?v=7Fqc4ObH2og
---
---
The path lines to the fuel distributor for you to have a better overall picture of the fuel lines (of course the transparent tube for testing pump is still connected and valve and hose are still removed):
http://www.youtube.com/watch?v=wJr7ZwQoQbc
---
Any comment about the sparks, pump, or the reason of this strange valve, sure will help a lot. Thanks!.
. Yesterday morning some hours checking, fuel or spark, or both. Conclusion, for sure, one problem is no fuel traveling.First we check for spark. I bought one of this:
...the one Landseer told me, sure it was better, but I haven't had time to get one of those. Also a new Varta battery with 830 CCA's is comming on monday.
We checked, on the coil wire... the light flashes ok. The pen needs to be in a darker environment for you to be able to see the light flashing (sometimes it's hard to see). The coil wire zone was easy to darken but when checking the spark wire #1 it was more difficult to see so we decide to remove one spark, hold it with a piece of wood over the engine and grounded to the unpainted part of the crossing bar. In the video you can see one or two sparks at the beginning of the crank. It is spark plug wire #1:
http://www.youtube.com/watch?v=3Y8W6loKDPE
Better than the video, I can tell you as a reference that in a 5 second cranking I see about 5 or 6 separate spark flashes. Dont know if thats good or not. But I think that if there is sparks this should mean that the distributor rotor is spinning, right?. James Bailey has doubts about the rotor, don't know if this clear the picture.
Then we checked for fuel. The easy way, clean a spark, tighten, 5 seconds crank, remove the spark and see/smell. It doesn't smell gasoline.
Then go back to the fuel pump. One question here, does the fuel pump should work just turning key to the right to the 'pre-crank' position? (where just the lights at the console turn on). We thought it should because just turning the key we can hear some flow inside the pump. In other thread today I have read that the pump only works when cranking or jumpering 30-87 terminals. So now I'm not sure if the pump should have moved yesterday just by turning the key.
In this video you can see the pump (the key just turned to the right). It does the same as the other day when jumpering 30-87. Almost no sound from the pump (if you pump up the volume you can hear some glop-glop-glop sound inside the pump when the camera gets really close to the pump).
http://www.youtube.com/watch?v=EIHbnNs44Ag
Another symptom to be worried with the pump..., if you let it some minutes like that, the pump starts getting hot. I mean that if you put your finger on the pump you have to take it out fast. I think that's not good. It is gasoline and I think it shouldn't get that hot. Of course we have been very careful monitoring that.
I will wait your answers of what you think about the health of this pump.
And in third place, what we think is some creative plumbing. We have detected on the fuel line (to the left, under the air intakes) a hose with what looks like a 'non-return valve' (or antiflow back valve) don't know how is called... that we think it is not factory. And dont know the reason why that is there. Any suggestion about what it is and why is there for?
---
A video of this hose:
http://www.youtube.com/watch?v=uXlvymVFEUM
---
We removed the hose and valve just to be sure of what it is. As Lauren Bacall said, if you put your lips together on the hose and blow, it let the air flow just in one direction of the tube, and that's what it does so as said seems a non-return valve:
http://www.youtube.com/watch?v=QPZQ4AOHD4U
---
---
Here is a transparent hose we connected to the fuel line just to check if there is some fuel flow. We just turn the key to the mentioned pre-crank position... fluids sound inside the pump, gets hot after some minutes, not even a drop on the transparent hose. We turn off the key. Maybe we should have jumper the 30-87 terminals (after reading other threads today) but I think the symptoms would have been the same described.
http://www.youtube.com/watch?v=7Fqc4ObH2og
---
---
The path lines to the fuel distributor for you to have a better overall picture of the fuel lines (of course the transparent tube for testing pump is still connected and valve and hose are still removed):
http://www.youtube.com/watch?v=wJr7ZwQoQbc
---
Any comment about the sparks, pump, or the reason of this strange valve, sure will help a lot. Thanks!.
Last edited by rockatansky; 04-17-2011 at 01:14 PM. Reason: adding some info
04-17-2011, 03:14 PM
#73
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Ok, so when you hooked up the spark pen to the coil wire, it flashed very rapidly?
When you were testing the spark plug #1, I only saw it spark a couple times, it should spark every time cylinder 1 gets to its ignition stroke, which happened quite a few times during your cranking. Hard to tell though.
Fuel pump, ok I have a couple concerns. First off, It shouldn't ever get hot at all. The fuel flowing through it keeps it cool. Only reason why it would get hot is:
1. if it is bad
2. Something is blocking its inlet or outlet fuel line
3. Something is blocking the return line
Another thing, it shouldn't be getting hot/getting power with the key turned to ON (pre crank), the pump is only activated when you are cranking the engine and then when it is running. Unless you jumped the fuel pump solenoid 30-87, then it will turn on with the key.
Here's something you can do, and not have to worry about blowing up your 928. Crimp/block/close the fuel line going to the fuel pump, then disconnect the pump from the 928. Take it to your shop and bench test it with a battery. To minimize chance of fire have someone to help you, connect the wires to the pump first, and then a few feet away, touch the wires to the spare battery for a second. The pump will buzz/jump/humm/make noise like a fuel pump should if it works. These fuel pumps do spin both ways if connected incorrectly. I would almost recommend you connect the pump backwards first, so the pump spins backward for a second, then re-connected it correctly. It should spin freely both directions. If there's no life from the pump, then its toast. Sometimes the pumps seize up after a couple years of not using them. This problem sometimes happens in 911s/931s (any porsche CIS) and I usually try to spin the pump backwards to free it, before I go ahead and replace the pump. You might get lucky too. When the pump is working correctly in a CIS porsche, you will definitely know its on. There will be a humming coming from the pump, and you will hear the fuel moving through the car almost like a woooshing sound.
keep at it, you've narrowed down the problems.
When you were testing the spark plug #1, I only saw it spark a couple times, it should spark every time cylinder 1 gets to its ignition stroke, which happened quite a few times during your cranking. Hard to tell though.
Fuel pump, ok I have a couple concerns. First off, It shouldn't ever get hot at all. The fuel flowing through it keeps it cool. Only reason why it would get hot is:
1. if it is bad
2. Something is blocking its inlet or outlet fuel line
3. Something is blocking the return line
Another thing, it shouldn't be getting hot/getting power with the key turned to ON (pre crank), the pump is only activated when you are cranking the engine and then when it is running. Unless you jumped the fuel pump solenoid 30-87, then it will turn on with the key.
Here's something you can do, and not have to worry about blowing up your 928. Crimp/block/close the fuel line going to the fuel pump, then disconnect the pump from the 928. Take it to your shop and bench test it with a battery. To minimize chance of fire have someone to help you, connect the wires to the pump first, and then a few feet away, touch the wires to the spare battery for a second. The pump will buzz/jump/humm/make noise like a fuel pump should if it works. These fuel pumps do spin both ways if connected incorrectly. I would almost recommend you connect the pump backwards first, so the pump spins backward for a second, then re-connected it correctly. It should spin freely both directions. If there's no life from the pump, then its toast. Sometimes the pumps seize up after a couple years of not using them. This problem sometimes happens in 911s/931s (any porsche CIS) and I usually try to spin the pump backwards to free it, before I go ahead and replace the pump. You might get lucky too. When the pump is working correctly in a CIS porsche, you will definitely know its on. There will be a humming coming from the pump, and you will hear the fuel moving through the car almost like a woooshing sound.
keep at it, you've narrowed down the problems.
04-17-2011, 04:02 PM
#74
Instructor
Thread Starter
Thanks rotaryboots, what you are saying match what I was thinking about the pump. I quote your message for answering...
Yes, when I did the test at the coil wire with the pen the flashings were many and did them rapidly.
When testing the spark plug first time, I count about 5 or 6 flashes in a 5 second cranking like the one in the video. The thing is that when I recorded the video and I look through the camera visor and later on the computer I only see 2 as you do...
I used an old battery but have in mind to retest the spark plug with the new battery that I will receive tomorrow, it is a 100 mAh battery and I'm sure that the car will prefer this one.
The other day, when we jumped the pump, it was not making sound neither, same as in the video. The strange thing is that if you put your ear very close to the pump you hear like fluid moving. This same sound could be hear when yesterday we didn't jumped but just turned the key to the pre-crank position.
For your words now I now that the pump only should spin when jumped or cranking the car. So, what we where hearing the day we did the 30-87 jump where a broken or jammed pump.
This is the test we will do to be sure that the pump has a problem. I have already read in many threads that fuel pump doesn't like to be stopped for long time.
Ok, some forward/backward conection to make it roll. It will surprise me that the pump is ok. But I would like to test it away from the car as you say to be sure and I have also found a bosch pump that probably I will be buying. Will be this one:
http://www.mister-auto.es/es/bomba-d...0!254!053.html
Good price having in mind that at the Porsche Center it's about 370 euros and I think it is the same part.
In any case I will buy it after testing the old pump on a bench for having a confirmation that the pump was toasted and eliminate possibilities.
Good to know too... I read some threads about people complaining about the noisy fuel pump of the 928, and that clears that I'm not becoming deaf.
Sure, I will confirm about the pump not working.
Without your help I will only have a bunch of iron...
Ok, so when you hooked up the spark pen to the coil wire, it flashed very rapidly?
When you were testing the spark plug #1, I only saw it spark a couple times, it should spark every time cylinder 1 gets to its ignition stroke, which happened quite a few times during your cranking. Hard to tell though.
I used an old battery but have in mind to retest the spark plug with the new battery that I will receive tomorrow, it is a 100 mAh battery and I'm sure that the car will prefer this one.
Fuel pump, ok I have a couple concerns. First off, It shouldn't ever get hot at all. The fuel flowing through it keeps it cool. Only reason why it would get hot is:
1. if it is bad
2. Something is blocking its inlet or outlet fuel line
3. Something is blocking the return line
Another thing, it shouldn't be getting hot/getting power with the key turned to ON (pre crank), the pump is only activated when you are cranking the engine and then when it is running. Unless you jumped the fuel pump solenoid 30-87, then it will turn on with the key.
1. if it is bad
2. Something is blocking its inlet or outlet fuel line
3. Something is blocking the return line
Another thing, it shouldn't be getting hot/getting power with the key turned to ON (pre crank), the pump is only activated when you are cranking the engine and then when it is running. Unless you jumped the fuel pump solenoid 30-87, then it will turn on with the key.
For your words now I now that the pump only should spin when jumped or cranking the car. So, what we where hearing the day we did the 30-87 jump where a broken or jammed pump.
Here's something you can do, and not have to worry about blowing up your 928. Crimp/block/close the fuel line going to the fuel pump, then disconnect the pump from the 928. Take it to your shop and bench test it with a battery. To minimize chance of fire have someone to help you, connect the wires to the pump first, and then a few feet away, touch the wires to the spare battery for a second. The pump will buzz/jump/humm/make noise like a fuel pump should if it works.
These fuel pumps do spin both ways if connected incorrectly. I would almost recommend you connect the pump backwards first, so the pump spins backward for a second, then re-connected it correctly.
http://www.mister-auto.es/es/bomba-d...0!254!053.html
Good price having in mind that at the Porsche Center it's about 370 euros and I think it is the same part.
In any case I will buy it after testing the old pump on a bench for having a confirmation that the pump was toasted and eliminate possibilities.
When the pump is working correctly in a CIS porsche, you will definitely know its on. There will be a humming coming from the pump, and you will hear the fuel moving through the car almost like a woooshing sound.
keep at it, you've narrowed down the problems.
Without your help I will only have a bunch of iron...
04-17-2011, 08:03 PM
#75
Rennlist Member
When my pump jammed, as I applied 12V to it, while close to it, I could hear it try to run , a sort of 'Uh' noise. Out of the car , held in the hand, it jumped and then started to get warm. On reversing the + and - wires, it briefly went 'Uh', then spit, and ran - it ejected whatever was jamming it, so its well worth a try. Your sounds sounds similar, but the jam may be more permanent.
jp 83 Euro S AT 53k
jp 83 Euro S AT 53k