Waking up a 17 year dormant 1984 928S
#136
On the male side of the 14 pin, on the Black/yellow you should be getting 12v while cranking. Not the female side with key on when it's unplugged.
#137
Former Sponsor
This is like watching a freshly caught fish flopping around in the bottom of a boat.
Quit looking for multiple problems. Repair the ground wires (properly) and re-attach them.
Remove the injectors and have them professionally cleaned. Clean the fuel rails and the rest of the system while the injectors are out for cleaning. If you haven't had the tank out and had it cleaned, start there. Replace all the flexible fuel lines.
Make sure the system pumps nothing but clear, clean fluid. Make sure you have spark. Re-install the injectors when they come back. Start the car.
Quit looking for multiple problems. Repair the ground wires (properly) and re-attach them.
Remove the injectors and have them professionally cleaned. Clean the fuel rails and the rest of the system while the injectors are out for cleaning. If you haven't had the tank out and had it cleaned, start there. Replace all the flexible fuel lines.
Make sure the system pumps nothing but clear, clean fluid. Make sure you have spark. Re-install the injectors when they come back. Start the car.
Last edited by GregBBRD; 06-25-2017 at 01:13 AM.
#138
#139
Rennlist Member
If you need the pinout of the L jet here you go, it may help. I would Follow as Greg says and make sure the lines are new (can't be too safe) and injectors are clean.
You need to service them anyway just to make sure the car is reliable.
You need to service them anyway just to make sure the car is reliable.
#141
Burning Brakes
Thread Starter
Good morning.
I just did this test and do not have 12v there were cranking.
EDIT - I only have 3.64 with the key in run position.
Let me be specific about how I did the test to make sure that it is correct.
I went to the 14 pin connector, left the top and bottom half connected but removed the cover from the male side. I then removed the black/yellow connector from the male side and put a test lead on it. When cranking the volts jumped around between a high of 10.6 volts to a low of 8 volts.
EDIT - does that mean it's time to clean the starter connections and alternator connections?
I just did this test and do not have 12v there were cranking.
EDIT - I only have 3.64 with the key in run position.
Let me be specific about how I did the test to make sure that it is correct.
I went to the 14 pin connector, left the top and bottom half connected but removed the cover from the male side. I then removed the black/yellow connector from the male side and put a test lead on it. When cranking the volts jumped around between a high of 10.6 volts to a low of 8 volts.
EDIT - does that mean it's time to clean the starter connections and alternator connections?
#142
Burning Brakes
Thread Starter
Pulled the cables off the starter, clean everything up, reattached it. No change in my readings. Still only 3.6 volts when not spinning and less than 12 (same 8-10) volts when the starters engaged.
#143
Nordschleife Master
First: I have to say I am impressed with your diligence and persistence. It's also nice to see the usual suspects chiming in to help out. I have very little knowledge of the L-jet, but it's nice to see the people who do know it helping.
Second: You posted a pic of a barrel connector back on page 7, saying it was behind the dash. Behind the pod on the left side? It's the wiring for the Euro fog light that the car doesn't have. You also have wiring for the Euro turn signal repeater lights (behind the front wheel on the fender) that you also don't have on that car.
Second: You posted a pic of a barrel connector back on page 7, saying it was behind the dash. Behind the pod on the left side? It's the wiring for the Euro fog light that the car doesn't have. You also have wiring for the Euro turn signal repeater lights (behind the front wheel on the fender) that you also don't have on that car.
#144
Burning Brakes
Thread Starter
First: I have to say I am impressed with your diligence and persistence. It's also nice to see the usual suspects chiming in to help out. I have very little knowledge of the L-jet, but it's nice to see the people who do know it helping.
Second: You posted a pic of a barrel connector back on page 7, saying it was behind the dash. Behind the pod on the left side? It's the wiring for the Euro fog light that the car doesn't have. You also have wiring for the Euro turn signal repeater lights (behind the front wheel on the fender) that you also don't have on that car.
Second: You posted a pic of a barrel connector back on page 7, saying it was behind the dash. Behind the pod on the left side? It's the wiring for the Euro fog light that the car doesn't have. You also have wiring for the Euro turn signal repeater lights (behind the front wheel on the fender) that you also don't have on that car.
#145
Burning Brakes
Thread Starter
Greg - I did repair the ground wires to the ECU, that didn't do it. I know it can be hard to follow this thread because it's become a bit rambling, but I put new ones close to the L-Jet connector that have a good continuity and confirmed good grounds to the grounding point that they are supposed to go to.
I also grounded four that were in the ring connector that I cut (probably mistakenly based on what I later found that was specific to the earlier cars), so I have good grounds to the ECU and the rest of the harness that those four ring connectors were grounded on. With all of that grounded still no ECU pulse. I am still seeing weird resistance in the ground, specifically when I test the ground the resistance varies..
Because I did not get a pulse even with the ground issue taken care of that led me to wonder if the ECU is getting adequate power when cranking, or if the ECU in fact good. I doubt what the previous owner told me about "ran great one parked" which is part of why am treating the ECU as suspect until I know it's good. Having a second one on hand for $100 is probably not the worst use of $100, or at least not the worst you some hundred dollars that I've ever spent.
Blake - thanks for the L-jet pins, that is the same diagram I've used for the last week or so. Using that I've confirmed continuity to the grounds and I have power where I'm supposed to. I do not have a good ground on the O2 sensor but I don't believe that's required to get it to fire.
This injection harness has been replaced and/or opened up before, and the car had rodents in the engine compartment so it's likely that there are multiple things going on. I believe I posted a picture of the L-Jet connector wear one of the wires was kinked and exposed.
I've decided, as some have already suggested (thank you) that it is time to remove the injection harness and sent it out to be rebuilt. If I am going to do the sort of big mile touring in this thing that I plan to this is not an area to have gremlins.
I also started to pull the fuel rail off (as Greg suggested and I was planning on anyway although I wasn't very explicit about that). As I suspected clean fuel came out. I had cracked open the test fitting on the passenger side and got fresh fuel there after replacing the fuel pump and filter. The gunk from yesterday must of been loosened up by the new fuel. I also had fresh fuel at the driver side rail when I loosened the fitting. The brown stuff on the rag is what came out yesterday, the fuel was completely clear today.
BTW - I used a crescent wrench to loosen the fittings to make sure I didn't strip anything.
And yes, the battery is disconnected.
I also grounded four that were in the ring connector that I cut (probably mistakenly based on what I later found that was specific to the earlier cars), so I have good grounds to the ECU and the rest of the harness that those four ring connectors were grounded on. With all of that grounded still no ECU pulse. I am still seeing weird resistance in the ground, specifically when I test the ground the resistance varies..
Because I did not get a pulse even with the ground issue taken care of that led me to wonder if the ECU is getting adequate power when cranking, or if the ECU in fact good. I doubt what the previous owner told me about "ran great one parked" which is part of why am treating the ECU as suspect until I know it's good. Having a second one on hand for $100 is probably not the worst use of $100, or at least not the worst you some hundred dollars that I've ever spent.
Blake - thanks for the L-jet pins, that is the same diagram I've used for the last week or so. Using that I've confirmed continuity to the grounds and I have power where I'm supposed to. I do not have a good ground on the O2 sensor but I don't believe that's required to get it to fire.
This injection harness has been replaced and/or opened up before, and the car had rodents in the engine compartment so it's likely that there are multiple things going on. I believe I posted a picture of the L-Jet connector wear one of the wires was kinked and exposed.
I've decided, as some have already suggested (thank you) that it is time to remove the injection harness and sent it out to be rebuilt. If I am going to do the sort of big mile touring in this thing that I plan to this is not an area to have gremlins.
I also started to pull the fuel rail off (as Greg suggested and I was planning on anyway although I wasn't very explicit about that). As I suspected clean fuel came out. I had cracked open the test fitting on the passenger side and got fresh fuel there after replacing the fuel pump and filter. The gunk from yesterday must of been loosened up by the new fuel. I also had fresh fuel at the driver side rail when I loosened the fitting. The brown stuff on the rag is what came out yesterday, the fuel was completely clear today.
BTW - I used a crescent wrench to loosen the fittings to make sure I didn't strip anything.
And yes, the battery is disconnected.
#146
Burning Brakes
Thread Starter
Picked up an injector harness from 928International along with some other bits.
They referred me to Ole for help on testing my L-Jet boxes. Stopped by to see him, super nice guy who couldn't have been more cooperative. He is going to let me know in a couple days.
I am going to focus on the injector rails, actual injectors and soft fuel lines for now.
The nice folks at 928 Motorsports and Devito's deserve a shout out as well for spending some time on the phone with me as well. Will find ways of spending some money with them on the journey.
They referred me to Ole for help on testing my L-Jet boxes. Stopped by to see him, super nice guy who couldn't have been more cooperative. He is going to let me know in a couple days.
I am going to focus on the injector rails, actual injectors and soft fuel lines for now.
The nice folks at 928 Motorsports and Devito's deserve a shout out as well for spending some time on the phone with me as well. Will find ways of spending some money with them on the journey.
#147
Nordschleife Master
That won't be terribly difficult.
No clue who Devito is, but one thing you can get from Carl (928MS) is the skid plates. They are heavy aluminum plates that go on your tow hook/front LCA mount and save your spoiler.
From the pics, it looks like yours is still intact. Carl's plates will protect it nicely.
No clue who Devito is, but one thing you can get from Carl (928MS) is the skid plates. They are heavy aluminum plates that go on your tow hook/front LCA mount and save your spoiler.
From the pics, it looks like yours is still intact. Carl's plates will protect it nicely.
#149
Race Car
^ yep. Fire hazard in waiting. Roger has the correct rail to injector hose. Retain and reuse the ferrules if they aren't rusted through. Some guys use hose clamps but generally not recommended. Plenty of debate in here about that subject.