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Discussion Starter #1
So I pull off in first, then to 2nd, put my foot down and at around 2.5k and only about halfway up the boost gauge I get an almighty jolt and the thing dies.

AA come out to help and we find the following:

Fuel pump is audible when turning on
Tach reads when turning over so CPS okay
Spark is fine
ECU fuses are fine
Compression good on all pots
No error codes stored
Info display says check OK
But there is NO INJECTOR PULSE

What can cause this?

I considered immobilizer fault (but I've read that doesn't just stop the injectors and also says key not recognised)

Is the ECU fuel cut is engaged, but why and how?

Are there any fuel cut switches or hidden noggins that can do this?

It's at my friends garage but I don't want him to spend hours fumbling around trying to work out what's wrong and rack up a bill if I can suggest to him what might be causing it.

I had been running with the W line disconnected for diagnostic purposes so had overboosted a few times earlier that day (spiked at 22PSI on my reader earlier that day). But had been driving fine after that so I don't see how it would be related.

If the T7 decided I was messing with things too much would it shut me out like that and how can I make it play ball again? I did promise it I'd leave the W line on but Herbie now won't go!

Thanks mateys
 

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Discussion Starter #4
Tested the plugs when turning over, there's power going to the plugs, nothing to the injectors. Would CPS throw a code? How do I eliminate that possibility?
 

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Tested the plugs when turning over, there's power going to the plugs, nothing to the injectors. Would CPS throw a code? How do I eliminate that possibility?
How did you go about testing the plugs?

No it does not always set a code for the CPS
and no it does not kill the ignition, only fuel (injectors)
You can check the resistance on the sensor, though I don't recall off the top of my head what the range is supposed to be
 

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Discussion Starter #7
AA guy had a light up tester, there's HT going to the plugs.

Local Saab indie told me there would be no spark if the CPS was gone.

They want £80 an hour to look at it plus I'd need it towed to them. Be cheaper to get my own Tech 2 device but don't have that money lying around. Bloody car.

I can reach the ECU via ODB2, I can get realtime data, no codes show. So the ECU isn't completely shot. But somehow it's not sending 5v pulse to the injectors.
 

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AA guy had a light up tester, there's HT going to the plugs.
I am intrigued by this tester. There's no access to the plugs while the DIC is installed, and the DIC shouldn't be pulled out. There are no plug wires. So how does this tester work?
 

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Discussion Starter #10
pull the cartridge off as if you were going to change the plugs, put testers over the plugs and hold the cartridge over the testers, then turn over and watch them flash.
 

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The DIC AND the plugs must be properly grounded when checking for spark
Removing the DIC and cranking the engine without proper grounding of each individual spark plug AND the cassette causes such a high resistance that gives a very high chance of killing the ECU and DIC

There's a chance that you may have caused more issues now
 

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I just solved this same issue and have registered just to share my outcome.

My 1999 t5 b204 saab 9-3 had a crank no start issue, injector pulse would flash once and then dissappear.

Injectors that are stuck or siezed will make the injector pulse turn off and not create a check engine light.

You can use a tech2 to activate the injectors and listen for multiple clicking (3-4 clicks per second) if you hear 1 click that's just the relay activation and the injector is stuck.
If you think it's stuck keep activating it while tapping the injector with a screwdriver.

If you don't have a tech2 you can use some cable or wires connected to 12v, then connect the 12v to injector to energise the injector, connect and disconnect the 12v to simulate the injector pulse and help free up the injector, also tap injector with a screwdriver.
 

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Good to know... I have a Tech II and have not explored it much. Also great to have a work around for the guys without one!
 
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