'80 cranks, no start, stumped a little...
#31
It was stored covered outside all this time. Unfortunately. So I am not sure if it would have dried up to that extent as that's how the car was also stored when it ran fine.
#32
Hi all!
Yes, another one of these countless no-start posts. But I just got out from under the hood and it's just a tad hot out there. I am SO ready for construction of my nicely air conditioned and heated shop behind the house to begin, but planning and zoning approval processes can be a pain.
Drove the car last about a week ago. No issues whatsoever, sings along perfectly as always. Parked it. Got in the car yesterday morning, car cranks, but no start. Didn't have time to check for anything, left in another car.
Tonight I checked the obvious things - fuel pump relay, is fine, put a known good one anyways, no difference, jumped it, pump runs, plenty of fuel in the pipes (or at least so I think after cracking one open and checking flow).
Put a noid light on a few injector plugs - pulsing nicely.
Injector grounds - look good, cleaned/tightened anyways.
Checked a couple plugs with a spark tester - pulsing nicely.
Pulled a couple plugs - beautiful light brown color, bone dry.
Made sure there is a timing belt - check, there! :P (Was only done 5k ago...)
So, now where to go? The thing that bugs me a little is that the plugs are dry and there is no fuel smell from the exhaust after all that cranking! I heard about a short taking out all injectors at once, but hmmmmm...seems weird for that to happen just from sitting...
Anyone having any ideas?
TIA,
Marcus
Yes, another one of these countless no-start posts. But I just got out from under the hood and it's just a tad hot out there. I am SO ready for construction of my nicely air conditioned and heated shop behind the house to begin, but planning and zoning approval processes can be a pain.
Drove the car last about a week ago. No issues whatsoever, sings along perfectly as always. Parked it. Got in the car yesterday morning, car cranks, but no start. Didn't have time to check for anything, left in another car.
Tonight I checked the obvious things - fuel pump relay, is fine, put a known good one anyways, no difference, jumped it, pump runs, plenty of fuel in the pipes (or at least so I think after cracking one open and checking flow).
Put a noid light on a few injector plugs - pulsing nicely.
Injector grounds - look good, cleaned/tightened anyways.
Checked a couple plugs with a spark tester - pulsing nicely.
Pulled a couple plugs - beautiful light brown color, bone dry.
Made sure there is a timing belt - check, there! :P (Was only done 5k ago...)
So, now where to go? The thing that bugs me a little is that the plugs are dry and there is no fuel smell from the exhaust after all that cranking! I heard about a short taking out all injectors at once, but hmmmmm...seems weird for that to happen just from sitting...
Anyone having any ideas?
TIA,
Marcus
This together with the thermotime switch is very important to have the car started ! So please check resistance of the thermotime switch (brown switch) and if you get power to the cold start injector during start (max 8secs)
#33
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In all the replies on your issue, I never saw the cold start injector mentioned.
This together with the thermotime switch is very important to have the car started ! So please check resistance of the thermotime switch (brown switch) and if you get power to the cold start injector during start (max 8secs)
This together with the thermotime switch is very important to have the car started ! So please check resistance of the thermotime switch (brown switch) and if you get power to the cold start injector during start (max 8secs)
For those playing along at home -- The starting fluid test is a quick troubleshooting technique that helps identify pretty much all fuel-related problems at once. If ignition is good, compression is good, the starting fluid will at least give a sputter and maybe a few seconds of run time. As Wisconsin Joe reminds us though, it's at least as dangerous as it is handy. Spraying and making a puddle then cranking, for instance, is a recipe for engine damage. Just a puff while cranking is all you need to help diagnose, and that's all you want. On the 928 with the sensitive cam drive, you MUST avoid anything that looks remotely like a backfire and risk of the engine rotating backwards. Ether risks a light-off in the intake cranking when there's a saturated mixture there, and that flame will continue to a nearby cylinder(s) that still has intake valve(s) open. Engine rolls backwards, belt rides up on the crank sprocket, and you jump time at best, break a cam nose more typically when the engine next turns correctly on the starter.
To the OP's issue, the 1980 car has an aux power feed from the battery to CE panel connection V4, dedicated to power to terminal 30 on the AFC (fuel injection) relay at position XVI. There's a test procedure for checking the integrity of that feeder and the connection at the battery, but the test protocol also has you remove, clean, and tighten the aux feeder connection at the battery positive post before you get out the meter to test. Symptoms of a poor aux feeder connection can easily include insufficient current available to "fire" the injectors, same as a weak AFC relay by the way. To test, remove the fuel pump relay, test for battery voltage at CE connections W2 (red with black tracer) and W3 (red with green tracer) with the connectors in place while cranking on the starter. Low voltage means poor connection. If voltage is OK, reinstall the fuel pump relay or jumper in the socket, crank again. If the engine starts, problem is AFC relay or fuel pump relay. Selectively replace the fuel pump relay and AFC relay to figure out which is preventing start.
Since the no-start magically went away after R&R of the battery, I'll speculate that the aux power feeder connection at the battery positive post clamp was the problem. Disassemble that now, clean it thoroughly with a detailer's brass toothbrush until it's shiny, then reassemble and tighten. I put a bit of Vaseline on the whole battery terminal and clamp after assembly to keep battery fumes from damaging the connections there. The ring terminal from the aux feeder is tinned copper, and the tin is sacrificial when the acidic fumes attack. So when you brush, you just want to remove the dull gray surface film, and avoid going all the way to the copper base metal. No sandpaper please, just the soft brass wire brush.
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mnotz (01-18-2020)
#34
Since the no-start magically went away after R&R of the battery, I'll speculate that the aux power feeder connection at the battery positive post clamp was the problem. Disassemble that now, clean it thoroughly with a detailer's brass toothbrush until it's shiny, then reassemble and tighten. I put a bit of Vaseline on the whole battery terminal and clamp after assembly to keep battery fumes from damaging the connections there. The ring terminal from the aux feeder is tinned copper, and the tin is sacrificial when the acidic fumes attack. So when you brush, you just want to remove the dull gray surface film, and avoid going all the way to the copper base metal. No sandpaper please, just the soft brass wire brush.
Thanks for chiming in, Dr. Bob! Much appreciated!
--Marcus