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Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 22893
Experience:  BEng hons Mech engineering, in auto industry 22 years
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1999 Saab 9-3 2.0L SE Turbo. Engine turned-over, fired, ran

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1999 Saab 9-3 2.0L SE Turbo. Engine turned-over, fired, ran for a couple of seconds then stopped as though the ignition had been switched-off. Now turns-over but doesn't even cough.
Coil pack, crank sensor and fuel pump replaced (all refurbs - pump runs but doesn't seem to lift [I am told]). Still turns-over but won't fire. Fuse and relays seem OK.
Already I've laid out around £200; I've still got the garage bill to come and still I don't have a car that runs.
Mileage stands at over 121k. Ran as sweet as can be until this.
Any suggestions other than scrap it?
Thanks, ***** *****


1st check for spark by removing one of the spark plugs and plug it back into its socket on the coil pack and rest it on the metal of the engine ( DO NOT hold it on place by hand) then have your assistant turn the engine over whilst you watch the plug. It should give a fat blue spark at regular intervals.

If not then check that there's power to the coil pack (at the other end of the plug lead) using a meter. If there’s 12V at the pack but no spark then check the ECU power supply (fuse and relay) and also the connections to the crankshaft speed sensor.

If there is a spark and its still not starting then its likely that the ECU isn't opening the fuel injectors, if the injectors are working you can hear them click - its difficult to hear them with background noise so use a long screwdriver like a stethoscope, placing the handle end in your ear and the metal tip against the body of the injector whilst your assistant turns the engine over.

If you can't hear anything check the ECU power is present by measuring voltage at the fusebox and on its relay socket if OK then check the connections to the crank speed sensor and consider replacing this sensor if the wiring / connections look OK

If the car will start using a squirt of quick/ easi start into the intake then this confirms the problem is lack of fuel

Customer: replied 1 year ago.
Hi Matt. Thank you for your response. From your suggestions all seems OK, it would appear that the fuel pump is not getting power. The pump does work but not on the car.
Any suggestions?



I'd next check over the fuel pump relay and fuse in the engine bay fusebox

check that you have 12V at the fuse with the ignition on and if thats Ok then consider replacing the relay

Customer: replied 1 year ago.
Hi Matt, thanks for your reply. If we get to the engine bay fusebox and all is okay with the fuel pump relay what next? Is this when we call in the auto-electrician or can more be done?


to be honest I usually just replace the whole wire at this point

so splice into the original loom with a fresh wire and then run that fresh wire back to the pump

and splice it back in

and then once its all connected, ten cut the original wire at both ends to isolate the damaged section out from the rest of the loom

Matt and other Car Specialists are ready to help you
Customer: replied 1 year ago.
Hi Matt, As requested I've rated you so now you should get paid. Thanks for your help, I'll let you know how things turn-out.
Thanks again, Trevor Gaw
Customer: replied 1 year ago.
Good Morning Matt. The guy I use as my mechanic (good with spanners but guess work and trial and error for problem solving) ended-up calling in an Auto-Electrician (think he didn't like the prospect of re-cabling) and it transpires that something in the ignition switch had failed causing the immobilizer system to activate. Guess the clue was in the description of events - "....stopped as though the ignition system had been switched off."
Expensive exercise but definitely one to remember.
Regards, Trevor