bureau13

These back-of-engine grounds, best attacked from above or below?

Mrmerlin

remove the aircleaner,
then then look for the fuel lines at the rear of the engine,
the grounds are under the crossing pipes

Hilton

So you need to do some basic tests next time the car dies..

Check the horn works - if it does, use that relay in each of the Fuel Pump, LH and EZ-F positions in turn to see if it fixes the no-start.
Is there spark when it dies and won't restart?
When it dies, if you jumper the fuel pump, can you hear the pump running?

The most likely suspects as identified by others above are: Relay, Fuel Pump, and Crank Position Sensor

You just need to figure out which one(s) the problem is. Once you know the specific problem, then you can decide your tolerance for swapping out old working parts for shiny new ones.

hwyengr

Coil ground wire isn't going to solve this problem, the coil itself is already grounded. The wire is to reduce interference for the windshield antenna.

If it had to be connected, you'd never have gotten it started if it was just plain disconnected.

bureau13

Yeah, that's what I figured on the coil ground, although it's interesting to know it's actual purpose.

I will check those engine grounds under the air cleaner, sounds like one of those things (along with cleaning up the CE panel) that's just a good idea, regardless.

Regarding the other diagnostic stuff...my horn actually does not work, so I don't know if I have a good relay there or not. The last time it happened, I did move it around to see if it would fix anything, but it did not. I did hear the fuel pump when I jumpered the fuel pump relay, but then it started....I didn't notice it before when it happened and I tried it, but next time I will.

The one thing you suggested about spark...how do I know if I have spark when it's failing to start? I'm not sure how to check for that.

Mrmerlin

take a spare spark plug and remove a plug wire,
put the spare plug in the wire,
then use a jumper wire with alligator clips and ground the plug electrode,
crank the engine see if you have a solid blue spark

DeWolf

To check for spark I disconnect the fuel pump relay and crank it a few times to get rid of fuel pressure. Then pull a plug and recoonect the plug wire and hold the plug against a metal part of the engine and get someone th crank the motor. You should see and hear the spark.

bureau13

Cool, thanks...next time it fails I will do that..

Barry Chan

I had a similar issue last year, died, cranks but no start, 2 days later and it starts right up, thought it fixed itself then drives and die again.....it was the fuel injection relay but mine is a 84, not sure its the same tho.

SteveG

Not if continuity of the ground degraded; then the ground from the coil may be intermittent. "Intermittent" seems to be the operative word here.

Bertrand Daoust

Here is where the driver's side coil ground is connected on my car.

bureau13

That looks similar to the empty screw hole I found on mine, although you seem to be missing the thick layer of sludge lol. Actually that part of my car is not so bad but it's hard to get down in there...I finally got an extension with a swivel down there and found the bolt I had wouldn't fit after all. Got a new bolt which hopefully will fit, but it's dark. I'll give it a shot tomorrow. Even if it's not the culprit here, it's one more thing that needs doing, so may as well do it.

OTR18WHEELER

I've been wrong before, and I am refraining from giving misinformation, but after reading both threads, I am wondering if it is not a fuel delivery issue. You said after it sits a while it will start, My thoughts were vapor lock? (doubtful), or clogged fuel strainer/ filter, or failing fuel pump. I have not had this problem yet, so I admit, I am just guessing here. My thoughts are if the fuel pump was weak, or restricted, it would cause loss of adequate fuel pressure, or put a load on the relay and cause it to fail. after a cool down period, or after the sediment clogging the filter resides, it starts again. seems plausible?

bureau13

I'm not ruling out anything at this point, but for what it's worth, it FEELS very electrical. I would expect a fuel delivery issue, other than e.g. a bad relay or pump electrical stuff, to not be so sudden. There were no signs, at all, prior to it dying on any of the occasions. Furthermore, simply cooling down didn't fix anything. This morning, after sitting all night, it didn't start until I was monkeying around with relays. Now, my monkeying around may or may not have had anything to do with it, but it didn't seem like a cool-down or clogged filter type of thing. Again though, you could very well be right, I'm certainly no expert.

Mrmerlin

Warning.... do not crank the engine and hold the plug and wire without adding the ground wire to the electrode with alligator clips a severe shock can result.

NOTE if you had a fresh sticker on the radiator ,. it would warn of this possibility