928S starting problem!
07-25-2001, 01:53 PM
#1
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928S starting problem!
Hello everyone!
This is my first post as a new member who just purchased an '83 928S in decent condition, auto tranny and 130K miles...I just did a plug change, oil + filter change over the weekend and now the car experiences starting problems.
It will start intially, run for a minute or two kind of rough and then stop. Upon restart it takes a few cranks to get it going again, it will run for a few seconds and then die again (unless I keep my foot on the gas)...On the third or fourth try it will keep cranking but it will NOT start...I did not give any gas while trying to restart.
At this point I have to wait a while before I attempt to start again...If I wait 5-10min. then I can start the car again, but the same symptoms persist - in other words, initially the engine will run for about a minute and then die again...After the third of fourth time it fails to start altogether.
It cranks but is not turning over.
Does this sound like a fuel pump/fuel starvation problem or maybe a vaccum problem?? I have not changed the fuel pump or filter since I bought the car and I have no idea how old they are. I checked the plugs, plug wires and distrubutor and everything seems ok there. The battery is fully charged.
Any suggestions, ideas, places to look next??
Thanks for your time!
This is my first post as a new member who just purchased an '83 928S in decent condition, auto tranny and 130K miles...I just did a plug change, oil + filter change over the weekend and now the car experiences starting problems.
It will start intially, run for a minute or two kind of rough and then stop. Upon restart it takes a few cranks to get it going again, it will run for a few seconds and then die again (unless I keep my foot on the gas)...On the third or fourth try it will keep cranking but it will NOT start...I did not give any gas while trying to restart.
At this point I have to wait a while before I attempt to start again...If I wait 5-10min. then I can start the car again, but the same symptoms persist - in other words, initially the engine will run for about a minute and then die again...After the third of fourth time it fails to start altogether.
It cranks but is not turning over.
Does this sound like a fuel pump/fuel starvation problem or maybe a vaccum problem?? I have not changed the fuel pump or filter since I bought the car and I have no idea how old they are. I checked the plugs, plug wires and distrubutor and everything seems ok there. The battery is fully charged.
Any suggestions, ideas, places to look next??
Thanks for your time!
07-26-2001, 04:55 AM
#2
Racer
There is no ease answer to this question.
Your 928 has what is call a CIS (Continous Injection System)or Bosch L-Jetronic.
You maybe better off taking it to a Import or Porsche shop for this one. It could be one of a number of different items or a combination of several.
It shouldn't be hard to find a shop near you for this possible injection problem. The CIS fuel system was used for years on VW's, BMW's, MB, Audi and I think Volvo just to name a few.
Here's a few checks for you.
(I don't know how much you know so please forgive me if the following seems a bit infantile.)
Make sure battery is in a full charged state and all battery terminals are clean.
Clean all ground points thought car.
Check all vacuum line.
Check and clean sensor conections.
Pull the coil wire and check for spark.
Pull a spark plug wire and check for spark.
Like the previous post refered to check or replace fuel filter.
Look in the Owners Manual to help you find the fuel pump relay on the fuse pannel. Once you have found it, turn the key to start (with car in nuteral and the parking break on) and see if you can hear the relay kick in and the fuel pump start running.
Note:
Now I'm not telling you, that you should do this to your fuel pump relay, I'm only telling you what I did to my fuel pump relay!
I took my fuel pump relay out and carefully removed the outside cover so I could see the coil and clean contacts and then left it off. I also do this so that I can run my fuel pump manualy without using any jumper wires.
Find the main fuel line comming from fuel pump going to the fuel distributor. This is the thing all your injector lines connect to. Take the line off (Most have banjo fitting so becarefull not to lose the two copper washers), place the line in a small jug and activate the fuel pump for 30-35 seconds. If your pump and filter are good you should see a fair bit of fuel in the jug.
If you have fuel at that point pull a injector line off at the injector and do the same.
I dont know what else I can suggest. Maybe someone else can come up with a few more?
HTH, KUP
Max
Your 928 has what is call a CIS (Continous Injection System)or Bosch L-Jetronic.
You maybe better off taking it to a Import or Porsche shop for this one. It could be one of a number of different items or a combination of several.
It shouldn't be hard to find a shop near you for this possible injection problem. The CIS fuel system was used for years on VW's, BMW's, MB, Audi and I think Volvo just to name a few.
Here's a few checks for you.
(I don't know how much you know so please forgive me if the following seems a bit infantile.)
Make sure battery is in a full charged state and all battery terminals are clean.
Clean all ground points thought car.
Check all vacuum line.
Check and clean sensor conections.
Pull the coil wire and check for spark.
Pull a spark plug wire and check for spark.
Like the previous post refered to check or replace fuel filter.
Look in the Owners Manual to help you find the fuel pump relay on the fuse pannel. Once you have found it, turn the key to start (with car in nuteral and the parking break on) and see if you can hear the relay kick in and the fuel pump start running.
Note:
Now I'm not telling you, that you should do this to your fuel pump relay, I'm only telling you what I did to my fuel pump relay!
I took my fuel pump relay out and carefully removed the outside cover so I could see the coil and clean contacts and then left it off. I also do this so that I can run my fuel pump manualy without using any jumper wires.
Find the main fuel line comming from fuel pump going to the fuel distributor. This is the thing all your injector lines connect to. Take the line off (Most have banjo fitting so becarefull not to lose the two copper washers), place the line in a small jug and activate the fuel pump for 30-35 seconds. If your pump and filter are good you should see a fair bit of fuel in the jug.
If you have fuel at that point pull a injector line off at the injector and do the same.
I dont know what else I can suggest. Maybe someone else can come up with a few more?
HTH, KUP
Max
07-26-2001, 10:21 AM
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Thank you Max for the extensive list of things to check....It is very helpfull...I know a fair amount about mechanics on a German car (owned several VWs + Audis previously), but I'm new to Porsche engine...I will take care of the simple checks and make sure the fuel pump is running correctly as per your suggestion....
Since I don't have any manual or owner's guide at this point, can you tell me which relay is for the fuel pump??? Is there a fuse # associated with the fuel pump as well?? I have checked all the fuses visually and they seem okay.
Your help and knowledge is appreciated...This is a great board
Tony
Since I don't have any manual or owner's guide at this point, can you tell me which relay is for the fuel pump??? Is there a fuse # associated with the fuel pump as well?? I have checked all the fuses visually and they seem okay.
Your help and knowledge is appreciated...This is a great board
Tony
07-26-2001, 10:25 AM
#4
Burning Brakes
To get info about fuses and relays, go to www.928gt.com then click on the appropriate fuse and relay charts.
BTW, at least get the Owner's Manual. They are only about $20. If you plan on doing any serious work on the car, you'll need the service manuals too. YMMV.
BTW, at least get the Owner's Manual. They are only about $20. If you plan on doing any serious work on the car, you'll need the service manuals too. YMMV.
07-26-2001, 01:21 PM
#5
Racer
Ed is right about the link:
http://www.928gt.com
Give one of the Big Three a call and see if they offer and book called
"How to Understand, Service and Modify Bosch Fuel Injection & Engine Management"
I don't know if it still in print but it is a good book and worth every bit of the 8-10 bucks it cost me many years ago.
Ed, had a good point about the Owners Manuel as well. An allmost have to have item.
Good luck, KUP
Max
http://www.928gt.com
Give one of the Big Three a call and see if they offer and book called
"How to Understand, Service and Modify Bosch Fuel Injection & Engine Management"
I don't know if it still in print but it is a good book and worth every bit of the 8-10 bucks it cost me many years ago.
Ed, had a good point about the Owners Manuel as well. An allmost have to have item.
Good luck, KUP
Max
07-29-2001, 02:46 PM
#6
Sorry To jump in so late. It appears you are running only on your cold start valve. When it (as it should) shuts off the engine dies. Since you are getting pressure to the cold start valve, it is probably too much control pressure. Check the pressure relief valve in the back of the fuel distributor for broken or missing o rings and check the wire mesh screen on the inlet line to the fuel distributor. If those are OK,recommend you ection maunal mentioned previously and a set of CIS fuel pressure tester ($60) to test the control pressure regulator (warm up regulator) and system pressure.
Good luck,
Dennis
DPW928@prodigy.net
Good luck,
Dennis
DPW928@prodigy.net