Advice for new owner ???
10-06-2010, 10:26 AM
#16
Proprietoristicly Refined
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Brakes. Air gets trapped in the tail of the slave. When doing brakes or clutch, the rear of the car has to be higher than the front. On a garage floor, I block the front wheels and put jack stands at max with a 4X4 on top of the jack stand under the rear. I use a simple hand vac pump.
If you cannot bleed correctly, go under the dash again and make sure the brake pedal has no pressue on the brake master cylinder. Unscrew the connecting rod---it shoud be adjusted after finish anyway so the brake pedal has 2 to 3 mm of travel.
If all else fails-------Motive Power Brake Bleeder 15 minutes and finished.
OK---No Start.
Basics
Get a new DME/Fuel pump relay or make a jumper:
http://www.clarks-garage.com/shop-manual/fuel-05.htm
Next, when you crank--watch the tach---joes the needle jump 1/16th of an inch? It hast to when cranking. If no "jumping" check the reference sensors. Check the connection at the rear top of the engine for dirt cracks in cable--clean.
Check the resistance of the sensors per Clarks:
http://www.clarks-garage.com/shop-manual/ign-02.ht
No Start check list:
http://forums.pelicanparts.com/porsc...checklist.html
Alarm--My best advice comes from Clarks:
http://www.clarks-garage.com/shop-manual/elect-23.htm
If you do not get the "tach bounce" and eliminated a lot of the other stuff.
DME computer. Try removing and inserting the big connector in the back.
Gently tap the computer while cranking. This checks the possibility of a cracked solder joint--if you are lucky. Grab the big connector again while cranking and wiggle--you are checking for a bad wire connection, again if you are lucky. Open the DME case and check for a burnt part or smell.
GL
John
If you cannot bleed correctly, go under the dash again and make sure the brake pedal has no pressue on the brake master cylinder. Unscrew the connecting rod---it shoud be adjusted after finish anyway so the brake pedal has 2 to 3 mm of travel.
If all else fails-------Motive Power Brake Bleeder 15 minutes and finished.
OK---No Start.
Basics
Get a new DME/Fuel pump relay or make a jumper:
http://www.clarks-garage.com/shop-manual/fuel-05.htm
Next, when you crank--watch the tach---joes the needle jump 1/16th of an inch? It hast to when cranking. If no "jumping" check the reference sensors. Check the connection at the rear top of the engine for dirt cracks in cable--clean.
Check the resistance of the sensors per Clarks:
http://www.clarks-garage.com/shop-manual/ign-02.ht
No Start check list:
http://forums.pelicanparts.com/porsc...checklist.html
Alarm--My best advice comes from Clarks:
http://www.clarks-garage.com/shop-manual/elect-23.htm
If you do not get the "tach bounce" and eliminated a lot of the other stuff.
DME computer. Try removing and inserting the big connector in the back.
Gently tap the computer while cranking. This checks the possibility of a cracked solder joint--if you are lucky. Grab the big connector again while cranking and wiggle--you are checking for a bad wire connection, again if you are lucky. Open the DME case and check for a burnt part or smell.
GL
John
10-06-2010, 08:16 PM
#17
Bleeding the clutch with a helper (old fashioned way) will probably improve things. Just make sure the helper knows he may have to pull the pedal all the way up at first.
10-06-2010, 11:32 PM
#18
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Hi Kerry, Make sure you are getting spark at the plugs. The engine can crank over all day and still not receive spark. On the Early 944's the Ignition Switch Module forward of the key will crack and not send the signal to DME to start. Go to Clark's garage.com at the link below. Be careful taking any plastic trim off as it breaks very easy. I had to change mine out on an 85.5 and it is much harder.
http://www.clarks-garage.com/shop-manual/elect-25.htm
Cheers,
Larry
http://www.clarks-garage.com/shop-manual/elect-25.htm
Cheers,
Larry
10-09-2010, 10:17 AM
#19
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Ladies and Gentlemen...
Thank you for your support and and help. But you just can't fix stupid... The spark issue is, in fact, caused by bad sensors. So, I bought two brand new sensors. I had them shipped overnight because, well, I'm a new Porsche owner and I'm excited. We've all been there, right? So... I install them according to instructions from the web. I spaced them at .8 mm from the flywheel. What my instructions left out was the fact that there is a small pin rising above the outer surface of the flywheel. I should have checked by rotating the flywheel. I know better. However, I didn't check. I didn't wait. I hooked up the battery and cranked. The race-bred engine sparked twice, maybe thrice before breaking one sensor off and bending the other.
I walked away.......
I'll get back to it when my new sensors come in.
Thank you for your support and and help. But you just can't fix stupid... The spark issue is, in fact, caused by bad sensors. So, I bought two brand new sensors. I had them shipped overnight because, well, I'm a new Porsche owner and I'm excited. We've all been there, right? So... I install them according to instructions from the web. I spaced them at .8 mm from the flywheel. What my instructions left out was the fact that there is a small pin rising above the outer surface of the flywheel. I should have checked by rotating the flywheel. I know better. However, I didn't check. I didn't wait. I hooked up the battery and cranked. The race-bred engine sparked twice, maybe thrice before breaking one sensor off and bending the other.
I walked away.......
I'll get back to it when my new sensors come in.
10-09-2010, 11:16 AM
#20
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Part of the learning process I guest,next time check twice even if your sure about it the first time.I,ve found out when working on my car & after parts are install the best thing to do is take a breake ,have a beer/smoke /coffee or whatever & get your mind out of it, then go back & recheck.Good luck next time.
10-09-2010, 12:41 PM
#21
Proprietoristicly Refined
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Ladies and Gentlemen...
Thank you for your support and and help. But you just can't fix stupid... The spark issue is, in fact, caused by bad sensors. So, I bought two brand new sensors. I had them shipped overnight because, well, I'm a new Porsche owner and I'm excited. We've all been there, right? So... I install them according to instructions from the web. I spaced them at .8 mm from the flywheel. What my instructions left out was the fact that there is a small pin rising above the outer surface of the flywheel. I should have checked by rotating the flywheel. I know better. However, I didn't check. I didn't wait. I hooked up the battery and cranked. The race-bred engine sparked twice, maybe thrice before breaking one sensor off and bending the other.
I walked away.......
I'll get back to it when my new sensors come in.
Thank you for your support and and help. But you just can't fix stupid... The spark issue is, in fact, caused by bad sensors. So, I bought two brand new sensors. I had them shipped overnight because, well, I'm a new Porsche owner and I'm excited. We've all been there, right? So... I install them according to instructions from the web. I spaced them at .8 mm from the flywheel. What my instructions left out was the fact that there is a small pin rising above the outer surface of the flywheel. I should have checked by rotating the flywheel. I know better. However, I didn't check. I didn't wait. I hooked up the battery and cranked. The race-bred engine sparked twice, maybe thrice before breaking one sensor off and bending the other.
I walked away.......
I'll get back to it when my new sensors come in.
There are BMW interchange sensors that sell for half the price of OEM. Only cable is shorter.
There are 3 small pins that stick above the flywheel. None will interfere with the reference sensors.
Something else is happening if the sensor bracket is not damaged or installed wrong.
John
10-12-2010, 07:25 PM
#22
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Yep. I got the BMW sensors. Nice tip! Thanks.
Look, here is a new situation. I installed and adjusted the sensors properly. NO SPARK. NO TACH JUMPING. Triple-checked the sensors for both adjustment and resistance readings. They are fine. The car did spark, and the tach did jump just before the ill-fated previous sensors were destroyed, but no more. Another curious new symptom is that I am now getting only 1.4 volts at the coil with the ignition on.
I have followed Clark's Garage instructions to the "T" for DME relay and Sensor checks. I have tried this with the relay in, with the relay jumped, with the alarm in place and with the alarm jumped (bypassed). All fuses in the fuse box are good. I see no damaged/corroded wires anywhere.
Do you suppose that when the sensors were torn apart by the flywheel they shorted or sent some pulse to the DME. destroying it?
I am now going back to Clarks Garage to read up. Anybody have any ideas?
Look, here is a new situation. I installed and adjusted the sensors properly. NO SPARK. NO TACH JUMPING. Triple-checked the sensors for both adjustment and resistance readings. They are fine. The car did spark, and the tach did jump just before the ill-fated previous sensors were destroyed, but no more. Another curious new symptom is that I am now getting only 1.4 volts at the coil with the ignition on.
I have followed Clark's Garage instructions to the "T" for DME relay and Sensor checks. I have tried this with the relay in, with the relay jumped, with the alarm in place and with the alarm jumped (bypassed). All fuses in the fuse box are good. I see no damaged/corroded wires anywhere.
Do you suppose that when the sensors were torn apart by the flywheel they shorted or sent some pulse to the DME. destroying it?
I am now going back to Clarks Garage to read up. Anybody have any ideas?
10-13-2010, 09:13 AM
#23
Proprietoristicly Refined
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DME computer. Try removing and inserting the big connector in the back.
Gently tap the computer while cranking. This checks the possibility of a cracked solder joint--if you are lucky. Grab the big connector again while cranking and wiggle--you are checking for a bad wire connection, again if you are lucky. Open the DME case and check for a burnt part or smell. John
Gently tap the computer while cranking. This checks the possibility of a cracked solder joint--if you are lucky. Grab the big connector again while cranking and wiggle--you are checking for a bad wire connection, again if you are lucky. Open the DME case and check for a burnt part or smell. John
Yep. I got the BMW sensors. Nice tip! Thanks.
Look, here is a new situation. I installed and adjusted the sensors properly. NO SPARK. NO TACH JUMPING. Triple-checked the sensors for both adjustment and resistance readings. They are fine. The car did spark, and the tach did jump just before the ill-fated previous sensors were destroyed, but no more. Another curious new symptom is that I am now getting only 1.4 volts at the coil with the ignition on.
I have followed Clark's Garage instructions to the "T" for DME relay and Sensor checks. I have tried this with the relay in, with the relay jumped, with the alarm in place and with the alarm jumped (bypassed). All fuses in the fuse box are good. I see no damaged/corroded wires anywhere.
Do you suppose that when the sensors were torn apart by the flywheel they shorted or sent some pulse to the DME. destroying it?
I am now going back to Clarks Garage to read up. Anybody have any ideas?
Look, here is a new situation. I installed and adjusted the sensors properly. NO SPARK. NO TACH JUMPING. Triple-checked the sensors for both adjustment and resistance readings. They are fine. The car did spark, and the tach did jump just before the ill-fated previous sensors were destroyed, but no more. Another curious new symptom is that I am now getting only 1.4 volts at the coil with the ignition on.
I have followed Clark's Garage instructions to the "T" for DME relay and Sensor checks. I have tried this with the relay in, with the relay jumped, with the alarm in place and with the alarm jumped (bypassed). All fuses in the fuse box are good. I see no damaged/corroded wires anywhere.
Do you suppose that when the sensors were torn apart by the flywheel they shorted or sent some pulse to the DME. destroying it?
I am now going back to Clarks Garage to read up. Anybody have any ideas?
No, the sensors did not ruin the DME computer. Usually age, battery drained, 12V short to chassis, water from leaking windsheild, user errors----not the sensors.
Your tests are leading the the DME computer being the problem----very common.
Did you do any of the tests I suggested on the DME computer? Tap, wiggle, grab big connector or open the DME case? You could even try to resolder a couple of known solder joints like others have tried.
https://rennlist.com/forums/924-931-...ferrerid=20449
OR
https://rennlist.com/forums/924-931-...referrerid=204
OR ???
http://www.944time.com/porsche/dme/index.php
It is beginning to look like the DME computer is bad. The only sure way to know is to get a good DME and put it in your car. You could send your DME to a couple of places to be checked for free-----with the assumption if your unit is bad, they will repair it or sell you a good used.
Used DMEs are available from members who have parts cars. You can post it in the WTB (want to buy) forums. A couple of parts choices--- www.apartabove.com or www.944ecology.com.
10-13-2010, 10:23 PM
#24
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Thanks for hanging in there with me John.
I agree. The PO's comment has much more meaning now than it did that day I bought the car! And yes, I did follow your suggestions. There was no change with either tapping the case or wiggling the plug. Incidentally, at this point I have checked every ignition and fuel component per Clark's Garage instructions. The only two things I have not done are the oscilliscope test on the sensors and opening the DME to check for damage. I do not have an oscilliscope and I called half a dozen people looking for one today. No dice.
944time.com mentions using an LED to test for the 2-2.5V pulse from the sensors in lue of an oscilliscope. The idea is that you will get a dim flicker as the pulse is generated. Have you ever done this? Would you figure that a 2.5V LED from Radio Shack would work?
The thing that pisses me off now is that it worked for 3-4 seconds when I put the first set of sensors in. I had all four spark plugs out and laying on the intake for a ground. The battery was charged well. When I cranked it, I witnessed spark on the plugs, heard the injectors firing and watched the tach jump. The sensors were broken because I set the distance on the reference sensor to .8mm at the outer surface of the flywheel, rather than the speed sensor to the teeth on the ring gear. They didn't live long! Then I bought two new Bosch 0 261 210 001 sensors (84-85 BMW 325E) and installed them. Now nothing. But no other element changed other than sensor adjustment. I must have harmed the DME in some way, but for the life of me, I can't think what.
You said "No, the sensors did not ruin the DME computer. Usually age, battery drained, 12V short to chassis, water from leaking windsheild, user errors----not the sensors." The battery was disconnected when I bought the car. I've been trickle charging the battery during this whole situation and a couple times I've jumped it with another car just to improve the cranking speed a bit. I'm just thinking out loud and rambling now. I'm agravated.
I became a Rennlist member today. I'm in this for the long haul now! This car will not beat me! Tomorrow I'm going to try the LED test on the sensors and open the DME.
Thanks again for the assistance !!!
I agree. The PO's comment has much more meaning now than it did that day I bought the car! And yes, I did follow your suggestions. There was no change with either tapping the case or wiggling the plug. Incidentally, at this point I have checked every ignition and fuel component per Clark's Garage instructions. The only two things I have not done are the oscilliscope test on the sensors and opening the DME to check for damage. I do not have an oscilliscope and I called half a dozen people looking for one today. No dice.
944time.com mentions using an LED to test for the 2-2.5V pulse from the sensors in lue of an oscilliscope. The idea is that you will get a dim flicker as the pulse is generated. Have you ever done this? Would you figure that a 2.5V LED from Radio Shack would work?
The thing that pisses me off now is that it worked for 3-4 seconds when I put the first set of sensors in. I had all four spark plugs out and laying on the intake for a ground. The battery was charged well. When I cranked it, I witnessed spark on the plugs, heard the injectors firing and watched the tach jump. The sensors were broken because I set the distance on the reference sensor to .8mm at the outer surface of the flywheel, rather than the speed sensor to the teeth on the ring gear. They didn't live long! Then I bought two new Bosch 0 261 210 001 sensors (84-85 BMW 325E) and installed them. Now nothing. But no other element changed other than sensor adjustment. I must have harmed the DME in some way, but for the life of me, I can't think what.
You said "No, the sensors did not ruin the DME computer. Usually age, battery drained, 12V short to chassis, water from leaking windsheild, user errors----not the sensors." The battery was disconnected when I bought the car. I've been trickle charging the battery during this whole situation and a couple times I've jumped it with another car just to improve the cranking speed a bit. I'm just thinking out loud and rambling now. I'm agravated.
I became a Rennlist member today. I'm in this for the long haul now! This car will not beat me! Tomorrow I'm going to try the LED test on the sensors and open the DME.
Thanks again for the assistance !!!
10-14-2010, 10:02 AM
#25
Proprietoristicly Refined
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I do not have an O scope. Not able to help on the LED idea.
Just repeating, did you replace the DME/fuel pump relay or make the 3 wire jumper per Clarks?
Did you inspect the wire connections at the back of the relay panel? Sometimes the connections burn/fry or just come loose when pushed in.
The negative ground by the bell housing has to be clean. There is another ground point near the negative gound that should be cleaned as well. There is a multiple ground point under the dash above the relay/fuse blocks. Clean.
Porsche says to clean all the harness connections at the top of the engine. Look very carefully at the wires and connections of the sensors.
If you do not get the tach bounce and the new sensors check with the correct resistance per Clarks, my only suggestion is the DME is bad.
The DME could (probably was) have been bad when you bought the car. I do not jump the battery with a battery pack or 2nd car because I am afraid of sending a strong AMP charge to the DME and fry the parts.
You are now at the decision point to get your DME tested or replaced.
GL
John
Just repeating, did you replace the DME/fuel pump relay or make the 3 wire jumper per Clarks?
Did you inspect the wire connections at the back of the relay panel? Sometimes the connections burn/fry or just come loose when pushed in.
The negative ground by the bell housing has to be clean. There is another ground point near the negative gound that should be cleaned as well. There is a multiple ground point under the dash above the relay/fuse blocks. Clean.
Porsche says to clean all the harness connections at the top of the engine. Look very carefully at the wires and connections of the sensors.
If you do not get the tach bounce and the new sensors check with the correct resistance per Clarks, my only suggestion is the DME is bad.
The DME could (probably was) have been bad when you bought the car. I do not jump the battery with a battery pack or 2nd car because I am afraid of sending a strong AMP charge to the DME and fry the parts.
You are now at the decision point to get your DME tested or replaced.
GL
John
10-14-2010, 12:15 PM
#26
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Hi there Kerry,
I am fairly new to Porsches as well as I just bought my 924S about 9 mo. ago. One thing I didn't see mentioned, I might have missed it but it bears mentioning repeatedly. Its my understanding that if the car has over 90k miles on it there should have been a timing belt, pully change, water pump and reseal done. If thats not in the reciept history you should do it while your are in there.
I am trying to remember, but I believe that the 84 does not have an auto tesioner on the belt system. It is VITAL to keep tabs on that tension. Is it every 15k for checking it guys? I believe Clark's Garage has a write up on it. With that said, the Porsche tension tool is rediculously expensive, so after talking with multiple people I settled on a tool call the Kricket. When checking the tension both I and a friend recieved exactly the same readings and the 223,000 mile engine is running fine. It is also worth it to get the special offset tensioning wrench, all of this is at Renbay for resonable prices.
I hope all goes well for you these are amazingly fun cars!
Pastor Mark
I am fairly new to Porsches as well as I just bought my 924S about 9 mo. ago. One thing I didn't see mentioned, I might have missed it but it bears mentioning repeatedly. Its my understanding that if the car has over 90k miles on it there should have been a timing belt, pully change, water pump and reseal done. If thats not in the reciept history you should do it while your are in there.
I am trying to remember, but I believe that the 84 does not have an auto tesioner on the belt system. It is VITAL to keep tabs on that tension. Is it every 15k for checking it guys? I believe Clark's Garage has a write up on it. With that said, the Porsche tension tool is rediculously expensive, so after talking with multiple people I settled on a tool call the Kricket. When checking the tension both I and a friend recieved exactly the same readings and the 223,000 mile engine is running fine. It is also worth it to get the special offset tensioning wrench, all of this is at Renbay for resonable prices.
I hope all goes well for you these are amazingly fun cars!
Pastor Mark
10-14-2010, 04:01 PM
#27
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John- I did the LED thing this morning. It worked great! Both sensors are sending good looking signals all the way to the DME connector. Although it is not as accurate as an O-scope, it does give a visual confirmation of signal. It took $6 at Radio Shack and I swear 5-10 minutes of time. I'm thinking about posting what I did. After I get this running....
On the DME relay; I tested the relay, opened and visually inspected the relay, check the relay signal paths to both the DME connector and the relay panel socket and the ignition switch, checked voltages. AND I've tried jumping it 3-wire style. I am confident that the DME relay and its wiring is good. I have also "pinned out" the DME connector per Clarks Garrage and 944time instructions. Every signal and or voltage is right where they said it should be.
The large/medium size underhood grounds have been removed, cleaned and re-installed. They were not bad to begin with. I have not cleaned the under-dash ground nor every connection under the hood. I will tonight.
I'm now getting ready to open the DME. I think it's bad too, but I'm going to look anyway. Then I'm gonna order another one!
Pastor Mark- I visually inspected the belt systems prior to turning the engine over. It's not bad for now. I'm going to replace everything as soon as I get this blasted thing to spark and start up! Say a prayer for me!
On the DME relay; I tested the relay, opened and visually inspected the relay, check the relay signal paths to both the DME connector and the relay panel socket and the ignition switch, checked voltages. AND I've tried jumping it 3-wire style. I am confident that the DME relay and its wiring is good. I have also "pinned out" the DME connector per Clarks Garrage and 944time instructions. Every signal and or voltage is right where they said it should be.
The large/medium size underhood grounds have been removed, cleaned and re-installed. They were not bad to begin with. I have not cleaned the under-dash ground nor every connection under the hood. I will tonight.
I'm now getting ready to open the DME. I think it's bad too, but I'm going to look anyway. Then I'm gonna order another one!
Pastor Mark- I visually inspected the belt systems prior to turning the engine over. It's not bad for now. I'm going to replace everything as soon as I get this blasted thing to spark and start up! Say a prayer for me!
10-14-2010, 04:37 PM
#28
Proprietoristicly Refined
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DME-----many used for the early cars. Usual price is around $100 up + SH.
If you want to get a reconditioned:
http://www.ecudoctors.com/
or
http://www.systemsc.com/failuremodes.htm
Added info on Clarks:
http://www.clarks-garage.com/shop-manual/dme-05.htm
Yes, the LED test sounds great!
GL
John
If you want to get a reconditioned:
http://www.ecudoctors.com/
or
http://www.systemsc.com/failuremodes.htm
Added info on Clarks:
http://www.clarks-garage.com/shop-manual/dme-05.htm
Yes, the LED test sounds great!
GL
John
10-14-2010, 05:06 PM
#29
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I didn't find any bad joints or water damage... I found a good, used DME on ebay for $100, free shipping and a DOA warranty. What the hell, right? Besides, I'm tired and sore from climbing in and out from under the dash. I could use a break. I'll just wait for the DME to arrive and go at it again then.
In the mean time I'll document the LED test...
Hopefully I can get past this and start enjoying the car!
In the mean time I'll document the LED test...
Hopefully I can get past this and start enjoying the car!
10-14-2010, 06:47 PM
#30
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Will do Kerry...I know that I tend to need all the help I can get when I work on a car! I usually end up praying for help...after I yell at the offending part for a while.
I do want to encourage you to go beyond a visual inspection and check the belt tension somehow. they are notorious about slipping and a slip of that belt means its bend rod city. It is the Achillies heel of an otherwise pretty bullitproof motor.
I do want to encourage you to go beyond a visual inspection and check the belt tension somehow. they are notorious about slipping and a slip of that belt means its bend rod city. It is the Achillies heel of an otherwise pretty bullitproof motor.