New (to me) '78 928 troubleshooting
01-21-2019, 01:53 AM
#76
Pro
Thread Starter
Following up on the cooling system condition finally...
I put the cooling system back together today, and used a venturi vacuum generator hooked to the vent line to the reservoir to pull the coolant and water down into the engine.
I was amazed to get another 2.5 gallons into the car, on top of the gallon that I'd put in it before the ill fated first start.
Once I fired it up again, it was "idling" at around 1800 rpm, so I suspect that I have at least one major intake leak to find and fix.
The coolant reservoir quickly ended up murky with the old coolant mixing with the fresh antifreeze and water that I'd just added, so I'm going to assume that the pump is actually circulating water.
The upper radiator hose started to warm up after a bit, as well as the top of the radiator.
I didn't run it more than about 5 minutes, as I don't have a functional engine temp gauge, as far as I can tell.
All told, I'm content with progress made today, and with the ease of burping the air out of the cooling system with a simple pneumatic vacuum pump. (The pump was the same one that I used to extract the skunked gasoline from the fuel tank.)
I put the cooling system back together today, and used a venturi vacuum generator hooked to the vent line to the reservoir to pull the coolant and water down into the engine.
I was amazed to get another 2.5 gallons into the car, on top of the gallon that I'd put in it before the ill fated first start.
Once I fired it up again, it was "idling" at around 1800 rpm, so I suspect that I have at least one major intake leak to find and fix.
The coolant reservoir quickly ended up murky with the old coolant mixing with the fresh antifreeze and water that I'd just added, so I'm going to assume that the pump is actually circulating water.
The upper radiator hose started to warm up after a bit, as well as the top of the radiator.
I didn't run it more than about 5 minutes, as I don't have a functional engine temp gauge, as far as I can tell.
All told, I'm content with progress made today, and with the ease of burping the air out of the cooling system with a simple pneumatic vacuum pump. (The pump was the same one that I used to extract the skunked gasoline from the fuel tank.)
01-24-2019, 06:56 PM
#77
Pro
Thread Starter
I haven't had much chance to work on the car this week, but I did find out that the reason I had the high idle was due to the ground wire for the idle air valve and the cold start injector not getting reinstalled after the cooling system was purged.
I'm going to have to reinstall the timing belt guard (and the ground wires), as well as testing all the engine wiring connections.
I did test the temperature sensor and while it appears to have nearly the same resistance on both sides of the sensor when measured to ground, there was no voltage present on the wiring.
This makes me think that I have either a wiring fault, or the cluster and central warning module are both having problems. I'm planning to probe the wiring at the gauge cluster connection, looking for continuity to ground, and if that is good, will be cleaning the gauge cluster flex circuit again.
On a related note, I followed some other people's path, printing and laminating my wiring diagram on 11" x 17" paper to make it easier to handle and trace out the circuits.
This is so much easier than scrolling constantly back and forth, zooming in and out as I shift pages!
I'm going to have to reinstall the timing belt guard (and the ground wires), as well as testing all the engine wiring connections.
I did test the temperature sensor and while it appears to have nearly the same resistance on both sides of the sensor when measured to ground, there was no voltage present on the wiring.
This makes me think that I have either a wiring fault, or the cluster and central warning module are both having problems. I'm planning to probe the wiring at the gauge cluster connection, looking for continuity to ground, and if that is good, will be cleaning the gauge cluster flex circuit again.
On a related note, I followed some other people's path, printing and laminating my wiring diagram on 11" x 17" paper to make it easier to handle and trace out the circuits.
This is so much easier than scrolling constantly back and forth, zooming in and out as I shift pages!
Last edited by Hey_Allen; 05-29-2019 at 01:08 AM.
01-24-2019, 07:40 PM
#78
Rennlist Member
Be careful probing the pod connectors for electrical issues - the blades inside the connector hoods are quite soft, and bend easily, to the point of losing contact - BTDT! I did that, and after reassembly I had wierd stuff like turning on side lights maxed the temp gauge . Another poster here wised me up, and after re-tensioning the blades all was good. On my 83 there are 3 ground contacts on the R (right) connector, and good contact here is essential. I suggest wherever you have electrical contact problems, apply some Deoxit - especially on the @#$%^ bullet fuse contacts!
jp 83 S AT 57k
jp 83 S AT 57k
01-24-2019, 07:46 PM
#79
Pro
Thread Starter
I hear you all too well on the contacts getting sprung, as well as on the DeoxIT.
Currently the right side of my gauges seem to all work, but the left side (fuel and coolant temp) are both not indicating anything.
I don't know on the speedometer yet, and the odometer reset is inop.
Loads of things to fix still, but I'm happy to have apparently found the cooling system issue, now that I managed to get another 2.5 gallons of coolant into the engine and radiator...
Currently the right side of my gauges seem to all work, but the left side (fuel and coolant temp) are both not indicating anything.
I don't know on the speedometer yet, and the odometer reset is inop.
Loads of things to fix still, but I'm happy to have apparently found the cooling system issue, now that I managed to get another 2.5 gallons of coolant into the engine and radiator...
01-24-2019, 10:05 PM
#80
Rennlist Member
Really late to the party and got tired of reading the small print on my phone...
1st congrats on saving an OB
as far as the fuel bung, I didn’t see where you had resolved the issue,!if you have, awesome. What I did on my 78 was remove the filter (there was no filter left, just plastic framework) pull the framework of the old filter off the housing (it is a snap fit), then buy the available filter, work the filter off the the housing until it pops off and snap it back onto the old housing (the threaded fitting with the nipple, and then screw it back in. Worked like a charm. I detailed it somewhere in my #30 thread.
hope this helped or made sense..:
1st congrats on saving an OB
as far as the fuel bung, I didn’t see where you had resolved the issue,!if you have, awesome. What I did on my 78 was remove the filter (there was no filter left, just plastic framework) pull the framework of the old filter off the housing (it is a snap fit), then buy the available filter, work the filter off the the housing until it pops off and snap it back onto the old housing (the threaded fitting with the nipple, and then screw it back in. Worked like a charm. I detailed it somewhere in my #30 thread.
hope this helped or made sense..:
01-25-2019, 01:37 AM
#81
Pro
Thread Starter
Airtek,
I haven't followed up on the fuel tank bung yet, as I decided that I wanted to see if there was any chance that the engine would even run before sinking any money on detail items that I wouldn't be able to salvage if I gave up on the car. That said, I should do so soon, since I now have it running, and am mostly chasing the somewhat smaller details now that I've passed that threshold.
Today's work got the AAV/idle valve and cold start injector grounded again, as well as tracking down the bottom WUR vacuum hose and connecting it. The hose had a screw threaded into it (poorly at that...) and once it was connected to the WUR, the idle dropped down to 1000-1100 RPM, and then down to 800-900 RPM once it warmed up a bit further.
I did find out that my radiator has a leak low on the right tank, somewhere along the forward seal, it looks like it's around 5" up. I'll have to drain and remove the radiator to take a closer look, and then see if it might be repairable or not.
I also found that the clutch does not work, in any way. I don't know whether it's the master or slave cylinder, but will probably have to at least pull the slave and see if having someone push the pedal pushes any fluid out. I suspect that it's the master cylinder, based on the various claims I see here about their behavior over time, but will test the easy stuff first.
After putting the car in gear before starting it (with the rear end supported on jack stands!) allowed me to test and find that I have no speedometer as well.
I did pull the 14-pin connector and jump post, and cleaned both. Wire wheel on a Dremel worked well to clean the jump post and it's terminals, and a few drops of DeoxIT should help as well.
The wiring to pin-1 on the 14 pin connector has insulation that is disintegrated, so I suspect that I know why it's having alternator fault indicated on the cluster, as well as a low voltage on the gauge. Another project to look into soon.
All told, a few victories tonight, but mixed in with a few new things to figure out.
I haven't followed up on the fuel tank bung yet, as I decided that I wanted to see if there was any chance that the engine would even run before sinking any money on detail items that I wouldn't be able to salvage if I gave up on the car. That said, I should do so soon, since I now have it running, and am mostly chasing the somewhat smaller details now that I've passed that threshold.
Today's work got the AAV/idle valve and cold start injector grounded again, as well as tracking down the bottom WUR vacuum hose and connecting it. The hose had a screw threaded into it (poorly at that...) and once it was connected to the WUR, the idle dropped down to 1000-1100 RPM, and then down to 800-900 RPM once it warmed up a bit further.
I did find out that my radiator has a leak low on the right tank, somewhere along the forward seal, it looks like it's around 5" up. I'll have to drain and remove the radiator to take a closer look, and then see if it might be repairable or not.
I also found that the clutch does not work, in any way. I don't know whether it's the master or slave cylinder, but will probably have to at least pull the slave and see if having someone push the pedal pushes any fluid out. I suspect that it's the master cylinder, based on the various claims I see here about their behavior over time, but will test the easy stuff first.
After putting the car in gear before starting it (with the rear end supported on jack stands!) allowed me to test and find that I have no speedometer as well.
I did pull the 14-pin connector and jump post, and cleaned both. Wire wheel on a Dremel worked well to clean the jump post and it's terminals, and a few drops of DeoxIT should help as well.
The wiring to pin-1 on the 14 pin connector has insulation that is disintegrated, so I suspect that I know why it's having alternator fault indicated on the cluster, as well as a low voltage on the gauge. Another project to look into soon.
All told, a few victories tonight, but mixed in with a few new things to figure out.
01-25-2019, 02:09 AM
#82
Rennlist Member
Speedo - there is a connector in front of the spare wheel, under a small fibre (IIRC) flap , to the right of centre of the spare - clean and deoxit this, and there is a good chance of a speedo working. Very common issue.
jp 83 Euro S AT 57k
jp 83 Euro S AT 57k
01-26-2019, 03:55 AM
#83
Pro
Thread Starter
I went looking for the cover and the speedo wiring, but only found the reverse light wiring? No cover, just wiring coming through a body plug from the right of the spare tire cubby hole, and held down with a sheet metal clip bent over the wire bundle.
I did get the clutch to free up, but either it's not releasing fully, or the synchros are all shot. I tried to shift into gear and the input shaft appears to have been still turning, as the gears would whine instead of neatly shifting into gear.
The trans shift linkages are also sloppy, the front ball joint has around 1/16" of slop if I move the rod around, and the rear joint is loose in just about every direction. I'm assuming that the rear shift bushings are gone, or nearly so.
I didn't find any of the other wiring faults tonight, it was cold. Hopefully I'll have the heater in the shop wired in tomorrow, making future night wrenching sessions more comfortable.
I did get the clutch to free up, but either it's not releasing fully, or the synchros are all shot. I tried to shift into gear and the input shaft appears to have been still turning, as the gears would whine instead of neatly shifting into gear.
The trans shift linkages are also sloppy, the front ball joint has around 1/16" of slop if I move the rod around, and the rear joint is loose in just about every direction. I'm assuming that the rear shift bushings are gone, or nearly so.
I didn't find any of the other wiring faults tonight, it was cold. Hopefully I'll have the heater in the shop wired in tomorrow, making future night wrenching sessions more comfortable.
01-26-2019, 10:15 PM
#84
Rennlist Member
You will have to clean up all linkage and clutch issues before you find out what condition your transmission is in. Be careful meanwhile!
01-27-2019, 12:02 AM
#86
Pro
Thread Starter
My car doesn't have the cover, and it appears that the metal strips in that picture are what I found folded over the wiring bundle.
I'm going to have to look at finding some interior pieces in better condition, as well, since even the ones in that picture look to be in considerably better condition.
Mine probably lost their shape due to sun and humidity, since they're somewhat floppy and the leather is faded between black and brown.
I'm going to have to look at finding some interior pieces in better condition, as well, since even the ones in that picture look to be in considerably better condition.
Mine probably lost their shape due to sun and humidity, since they're somewhat floppy and the leather is faded between black and brown.
01-27-2019, 01:53 AM
#87
Rennlist Member
Usually the speedo leads are in that bundle, so make sure the connections in there are clean and Deoxited. Then you can exclude problems there as the cause.
jp 83 Euro S AT 57k
jp 83 Euro S AT 57k
01-28-2019, 01:05 AM
#88
Pro
Thread Starter
While I have not dug into the speedometer wiring further today, I did verify that the two thin wires are present in that bundle, and appear to be connected. I'll follow up on that later this week.
Today I got a late start working on the car, as the priority was to get an outlet wired in for the electric heater that I have had sitting for a few weeks.
While not very useful with the garage door open to allow exhaust to be removed, it will allow me to work in my shop at any other time.
Actual car work included installing a 21" V-belt, eliminating the seized emissions air pump.
NAPA supplied a 4L210 belt which fit with a bit of fiddling to get the bolts aligned, and then pulled it snug as the bolts were tightened.
O'reillys was just about useless to find it, if it wasn't an application lookup item. Once I got someone who understood that I didn't want the "correct" belt for my application, they didn't have it in stock.
Beyond that, I pulled the cluster to check the wiring, as I'd had it out once before, and applied DeoxIT on all the bulb sockets and contacts, since they were all corroded.
This time, I found generally clean copper contacts, and green copper oxide sludge that wiped off with a shop towel.
I haven't reinstalled the cluster yet, as I want to check the pinout on the speedometer, but the DeoxIT appears to have done an amazing job at removing the corrosion that was there.
Today I got a late start working on the car, as the priority was to get an outlet wired in for the electric heater that I have had sitting for a few weeks.
While not very useful with the garage door open to allow exhaust to be removed, it will allow me to work in my shop at any other time.
Actual car work included installing a 21" V-belt, eliminating the seized emissions air pump.
NAPA supplied a 4L210 belt which fit with a bit of fiddling to get the bolts aligned, and then pulled it snug as the bolts were tightened.
O'reillys was just about useless to find it, if it wasn't an application lookup item. Once I got someone who understood that I didn't want the "correct" belt for my application, they didn't have it in stock.
Beyond that, I pulled the cluster to check the wiring, as I'd had it out once before, and applied DeoxIT on all the bulb sockets and contacts, since they were all corroded.
This time, I found generally clean copper contacts, and green copper oxide sludge that wiped off with a shop towel.
I haven't reinstalled the cluster yet, as I want to check the pinout on the speedometer, but the DeoxIT appears to have done an amazing job at removing the corrosion that was there.
Last edited by Hey_Allen; 01-31-2019 at 12:34 AM.
02-03-2019, 03:45 AM
#89
Pro
Thread Starter
Digging into the wiring again, I was cleaning up the cluster wiring more, and got over-eager and fitted a set of LED bulbs in the larger bulb sockets.
This led to realizing that the bulbs were designed for a different socket, where the wires coming down one side of the wedge base, and wrapping over the end to the other side didn't cause a direct short circuit.
I realized that I had a problem as soon as I turned the ignition on, and the battery indicator (which uses one of the large bulbs!) was short circuited and burned one of the traces on the flexible circuit.
After wiring over the damaged circuit trace, and replacing all the bulbs with the glass incandescent bulbs that I'd just taken out, the battery indicator worked again, but now I have no gauge lighting.
Testing at the fuse shows battery voltage, as well as on connector F5, but I don't have any voltage at the dimmer wires.
What is in between these points, that could have failed when the back lighting bulbs shorted that circuit? I would have expected that the fuse would have blown, but it didn't.
Other than that, it's looking like the fuel gauge is now working, as well as the temp gauge, though I need to test at the 14 pin connector since the temp sensor isn't seeing any voltage yet.
Slowly making progress with the issues on this car...
This led to realizing that the bulbs were designed for a different socket, where the wires coming down one side of the wedge base, and wrapping over the end to the other side didn't cause a direct short circuit.
I realized that I had a problem as soon as I turned the ignition on, and the battery indicator (which uses one of the large bulbs!) was short circuited and burned one of the traces on the flexible circuit.
After wiring over the damaged circuit trace, and replacing all the bulbs with the glass incandescent bulbs that I'd just taken out, the battery indicator worked again, but now I have no gauge lighting.
Testing at the fuse shows battery voltage, as well as on connector F5, but I don't have any voltage at the dimmer wires.
What is in between these points, that could have failed when the back lighting bulbs shorted that circuit? I would have expected that the fuse would have blown, but it didn't.
Other than that, it's looking like the fuel gauge is now working, as well as the temp gauge, though I need to test at the 14 pin connector since the temp sensor isn't seeing any voltage yet.
Slowly making progress with the issues on this car...
02-03-2019, 05:46 AM
#90
Burning Brakes
Your speedo issue is prolly an open circuit at the rivet and the brass strip on the back of the speedo cluster... Clean well with scotch bright then float over the strip and rivet with a bit of solder.. Do all of them while you are in there 78 clusters are really easy to get to.
Sorry like Airtech I am late to the thread I have brought back lots of these old ones as nice drivers currently have 12 just bringing back a 79 at the moment... Any questions fee free to pm me.
Paul
Sorry like Airtech I am late to the thread I have brought back lots of these old ones as nice drivers currently have 12 just bringing back a 79 at the moment... Any questions fee free to pm me.
Paul