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Old 05-09-2021, 08:23 PM   #1
bionicbanana
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Default Another Intermittent No-Start Thread

93 940 Turbo



Had a cold morning a few weeks ago and car wouldn't run for more than half a second, sputtering badly. Eventually fired up and ran great for a week or two with no issues (aside from a blown turbo, burning a lot of oil under normal driving). Replaced the turbo with another 13c I had lying around and drove fine until the next day, when the problem occurred once again when cold, and again after starting it back up warm, basically limping it to a friend's place up the road travelling 2 miles an hour in 1st

Since then the issue has stuck around and the car has been basically undriveable. Disconnecting the battery for an hour+ seems to do the trick until it's turned off and started again. Here's a list of things I went through already, some of which not seemingly related:

Cleaned MAF and connection. Had the battery disconnected during this time and it started fine after, good ground and 2.5v between pin1 and pin3 at idle.
Swapped with another known working MAF, no change
Two different coils, tested working, no change
New plugs + boots cleaned. Spark on all 4 when cranking
IAC + connector cleaned
Air Filter cleaned
Tried another radio suppression relay, no change
CPS connector cleaned, not tested
02 sensor + connectors cleaned, not tested
Ignition + cam timing verified
All visible engine grounds and battery terminals cleaned and tested
Not getting diagnostic codes, only 1-1-1
Swapped fuel pump relays, both pumps priming with key turned
Swapped power stages, no change
Cleaned ECT connection, not tested
Cleaned TPS connector, ran diagnostics which tested okay
All fuses checked and replaced

Most recent was swapping the MAF, and once again it started up and drove great after having the battery unplugged for a bit. Got back from the drive and wouldn't restart.

I suspected it was a charging issue since I wasn't always getting dash lights with key turned, though that's been a reoccurring problem over the past few months (neglected). It would however drive fine with working speedo/odo even without warning lamps on with key turned up until recently. Today the cluster was pulled and we basically just fiddled with connections and now I'm getting lights again, with 12v at the exciter wire at alternator.

Not sure where to go from here. I could be wrong, but it seems to not be a fuel or mechanical issue given the intermittency of the issue, and the fact that a battery reset seems to work.

Another thing to note - the ignition switch/starter is sticking a bit, and still cranks for a second when key is turned back to ON. It's been doing this for a few months though. I assume that much more fuel is being sprayed by the injectors while cranking vs idling. Is it possible the problem has worsened and now it's flooding itself?

Any help is appreciated. Thanks

Last edited by bionicbanana; 05-09-2021 at 08:34 PM..
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Old 05-09-2021, 10:06 PM   #2
ZVOLV
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Got a test lamp?
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Old 05-11-2021, 08:56 AM   #3
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Quote:
Originally Posted by ZVOLV View Post
Got a test lamp?

Should somewhere. Been using a multi to test everything else
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Old 05-11-2021, 10:37 AM   #4
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Quote:
Originally Posted by bionicbanana View Post
Should somewhere. Been using a multi to test everything else
A meter is the wrong tool for testing power circuits. I've been informally, and formally, trained on this.


Test lamp from coil NEGATIVE to ground. Key on, illuminate? Crank, blink? = (ignition pulse)


Peel back the boot on an injector connector, unplug the connector, crank, BLINK? =fuel injector pulse.

I bet its your crank sensor, or possibly the "injector" relay (aka radio interference relay)
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