Tamaren

So I just finished my hesitation problem by fixing a vacuum leak I found, and went to take it for a drive, and it would not start- no crank.
troubleshooted all of the issues with that, and pulled relays/14 pin/ and found nothing of concern, but cleaned the bridge (starter) relay contacts and it would crank.

Was a little flooded from my cranking earlier, but got her started and out on the road. Went to the gas pump, filled up, and was merging onto the freeway under acceleration at about 4 grand and it just turned off, engine wise. I still had guages, radio even, but the engine acted like I flipped the ignition switch.

pulled over to the side of the road, then cranked a few times, eventually sprang to life and drove home like nothing happened.

The similar symptom of it just switching off has happened twice before, both in the last month, but it was more of a 2 second hesitation and I never even left the gear.

Things it's not:
Brand new fuel system, back to front.
Fuel pump relay
Plugs/wires/distributor

Things I haven't replaced that are related:
injection relay
coil
Ignition box
L-jet brain
Barn door (however, I have inspected it and it is in excellent shape)

Any thoughts?
I have learned a lot over the past few years from y'all, and I really appreciate the help. I'm about 15k into her, figure I better get everything taken care of!

nosnow

Sounds like the cps (crank position sensor) might be going out. It is located under the airbox about the fly wheel. It is also possible you caused the connector to separate if your vacuum hose was in that area.

Tamaren

Do not believe I have one of those, Sorry I forgot to include it's an '81 5 speed US spec. L-jet.

PorKen

Is the green-wire* green? If it's old and brown, it may cause problems.

The L-Jet brain is pretty robust.



*distributor pickup wire to ignition box

Tamaren

That... Is something I haven't checked. It looked to be in good condition when I bought the car, but that could be deceiving. I may order one just to be sure.

I'm doing injection relay and most likely green wire just to be sure.

I'm not completely sold that the problem I had with the starter wasn't related to the dying, but I don't know for sure. My car is by no means a basket case electrically (most hasn't been touched) which I think isn't helping anything.

Fogey1

"... but the engine acted like I flipped the ignition switch. ..." Maybe you did, effectively. I didn't notice a new ignition switch in your list of things it's _NOT_.

Symptoms match. Search ignition switch.

Tamaren

Not saying it's impossible, but it's never given me trouble. There is resistance between on/run/off/acc, and it always seems to be correct.

I will look into it. It is usually the switch behind the key so I don't have to re-key the car, correct?

Mrmerlin

check and clean the battery connections and replace the ground strap at the battery

Fogey1

Correct.

I suggested the search because there are a lot of miracle stories about replacing this 36yo switch and curing intermittent faults.

bogdann

Long shot but I had a similar problem with mine with damaged injector wiring. Found when I was idling the engine and moved a wire to get access and the engine died. Did it two more times with same result, slight movement and engine died. Tested other 7 leads and all okay. Rebuilt all 8 leads. Most of them were in poor condition.

Tamaren

Update- Green wire and fuel injection relay are in, I would say that it wasn't helping anything. See pictures.

Doing rotor/cap for the hell of it while I am in there, better than taking it apart later. As intermittent as a problem as this is, we will find out in a week or so if it worked!

Speedtoys

Well, that matches a lot of things.

And most of those things are easier and cheaper to check first than pulling the pod and spending $100 on a maybe.

outbackgeorgia

Pull the pod? $100? Wow, prices have gone up. I don't recall pulling the pod for the switch, just two tiny screws

Speedtoys

$107.32 MSRP.

And if after 30yrs its died..time to fix other things too up there...?

But like I said, simple relay/wire/corrosion should be coming first, and a lot of those share this same symptom.

Tamaren

It would of fired right back up I would figure if it was ign. Switch. But it cranked for a while.

Not it to say I won't replace it because I eventually will, I just don't think that is my problem directly.