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240 '92 3.1 Intermittent No-Starts

XxJenoxX

Skin Suit
Joined
Apr 25, 2010
Location
Pittsburgh, PA
Can anyone link me to the no-start thread? Couldn't find it.

Also taking advice on troubleshooting intermittent no-starts. '92 wagon with 3.1, m47. Not a lot of rhyme or reason to when. Windshield leaks like a sieve. Cranks like a motherf7cker, but just won't fire up. Doesn't matter if it's got almost no gas or a full tank. Wouldn't start damn near on E last Friday, got it to the gas station, wouldn't start again with a fresh tank.

Gonna start with reflowing the solder in the fuel pump relay. I replaced it with another I had, but that one was a used relay that came with the last car, so I'm not going to be the least bit surprised if it's still the problem.
I've spun the fuses, replaced the fuel pump fuse, no dice.

The damn thing always seems to start JUST as I'm about to employ the next option. One more try to demonstrate to a coworker that it won't start before I swap the relay, and away it goes.
One last try before I tape a piece of wire in to jump the pumps at the gas station, and away it goes.
 
Not yet, it always happens when I'm in a pinch and throwing available parts or pieces of wire at it are quicker than verifying fuel or spark. And then it always starts before I give up and troubleshoot.

I really wanted to tackle it over the weekend, but it was non-f7cking-stop sheets of rain.
 
Moisture non starts on a 240 can be better terminals, fuse at battery, fuses getting wet from windshield leaks or moisture, wet junction block at fender, grounds at intake manifold. On a 740 it's usually bad hood seal and wet dist. Good luck.

Spark test takes 10 seconds and you CAN lean out the door and crank and see if spark or not.
 
Alright, so...Flat out refused to start after work. Had to get a ride home and get the XC on the road again.

So far:

Has spark. Screwdriver in a wire confirmed.
Jumping the pumps at #4 and #6 produces noise from the main pump.
Unscrewing the cap on the schrader valve at the rail gives me a little fuel.

So I have fuel and spark. No reason why I wouldn't have air. Obviously don't know if I have enough fuel pressure to start yet, but there is absolutely no sign of an attempt to ignite any fuel, and no fuel from the exhaust. So it seems an awful lot like it's getting absolutely no fuel at all.

Injector pulse gone?

If I can get it started at work tomorrow, I'll drive it home and get a ride back to pick up the XC so I can troubleshoot it here.
 
It's always the CPS. 10mm bolt and very long extension. Just hope the bolt isn't stuck on there.
 
Injector pulse gone?

If you can have someone else crank, hold a screwdriver tip against an injector body and listen with your ear next to the handle. You'll hear and feel them tick-tick-tick (pseudo stethoscope). Fuel rail with a schrader valve makes fuel pressure checking easy peasy, probably a worthwhile endeavor to do that while you're at it, if you can find/borrow a fuel pressure gauge kit
 
I can probs get my hands on a kit over the weekend. I found a good LED to use as a tester. I doubt all of the injectors themselves failed all at once, so if I can just probe an LED into the connector, that should be good enough to test the pulse.
 
I too thought "hmm i have spark, fuel, air, compression, and it’s timed right, why the F*** won’t this thing start?" But then I realized, an iffy crank sensor can cause all kinds of weird things to happen. It will tell the ECU that the crank is at x position when it’s really at y position.

In conclusion: you can have fuel and spark with a 'bad' crank sensor and will have a no start. AFAIK, the only time you will fully lose spark and or fuel from a crank sensor is if it’s completely dead. Yours seems to have failed in the exact same manner as mine. Sometimes it’s good sometimes it’s not. It probably depends heavily on humidity and temperature. By the way, are the wires frayed?? Even if they aren’t it can still be bad.

Lastly, if you’re not feeling spendy but still wanna 'Fire the parts cannon', check out amazon for the sensor. It’s some no name crap i think and I generally wouldn’t condone buying that, but at $14 shipped you can’t go wrong. But maybe save up for a bougicord in the future..
 
$36 won't break the bank for the daily. Don't they usually cause a stall and no-start when they fail? Ala getting hot and crapping out? I know it's not impossible even in this situation, but it runs absolutely and then won't start again, whether it's minutes later or hours.

I'm limited in what I can do in my employer's parking lot without drawing too much attention. If I can just get ONE more start out of it to get it home, I'll be good to go.

The reason injector pulse comes to mind is absolutely no fuel smell after many, many tries to start, and the ecu's being mounted to the firewall, well...I'm not kidding when I mention how bad this thing leaks and it f7cking POURED all weekend. And today is the first day it has just not wanted to start every single time I got in it.
 
I can probs get my hands on a kit over the weekend. I found a good LED to use as a tester. I doubt all of the injectors themselves failed all at once, so if I can just probe an LED into the connector, that should be good enough to test the pulse.

You're going to need a resistor for that (try 600 - 700 ohm). And you need to make certain that the LED / resistor are well insulated (never touch ground).
 
The el cheapo Delphi branded crank sensors I bought on ebay have worked well for me. They are cheap enough that you can buy two and have a good one for stash for when it fails again for the price of one bougicord. I've had dead bougicord ones out of the box. Thus my disloyalty to the brand now. FCP handled the return very quickly which was nice and the next one was fine.

Random no starts are electrical a lot of the time on these. Stuff like the powerstage, the crank sensor, Dirty connections on the coil, powerstage, and bad coil wires. Lastly don't rule out the spark plug gap. We had a recent thread where the plugs were very worn with a huge gap contributing to poor starting.

That weirdness described above with the crank sensor is something I experienced with my moms 245 a long time ago. It took months till the thing finally croaked and could be diagnosed. Mom would call and say the car won't start. We would get there and the thing starts up. Drives fine. Finally it wouldn't start at all in front of her house so that made it easier to figure out that there was no spark. No triggering.

Oh yeah, make sure the crank sensor has a white tag on the cable near the connector to the car harness. That indicates it's the supposed updated better version. lol. The original ones were known flaky and had a yellow marker on them.
 
Any fault codes after trying to start? Diag box pin2 is ECU; pin6 is EZK.

Gonna add that to the list, too.

Mom also mentioned the damn radio suppression relay.

I've got resistors out the wazoo at work, won't be a challenge to make that happen.

Highly doubt spark plugs. Done in the last 6 months and I doubt they'd ALL fail at once in such a scenario. Coil connections were good.
 
Gonna add that to the list, too.

Mom also mentioned the damn radio suppression relay.

I've got resistors out the wazoo at work, won't be a challenge to make that happen.

Highly doubt spark plugs. Done in the last 6 months and I doubt they'd ALL fail at once in such a scenario. Coil connections were good.

No RSR on a 240. And to answer your question above ?don?t they usually cause a stall and no start when they fail??, my 740 never ever stalled. Ran glass smooth with full power. It was just when we?d turn it off it would sometimes not restart.
 
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