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Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Audi
Satisfied Customers: 1516
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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Audi A4 Cabriolet: . Have a 2003 a4 with 1.8t. Stopped running,

Customer Question

Hi. Have a 2003 a4 with 1.8t. Stopped running, dealership replaced fuse 29 for ecu, started and blew out again. Determined wiring harness at the coil packs was shorting. I spliced new harness in. Coils sparking, fuse 29 good, not starting. When cranking gurgling, somewhat back firing coming from intake throttle body...getting fuel, plugs soaked with fuel...replaced plugs...nothing. Possible camshaft
Submitted: 1 year ago.
Category: Audi
Expert:  Juan Crespo replied 1 year ago.
Hi there. Welcome to our site. If there is spark and fuel in the cylinders, the only thing that cwould prevent the engine from starting is lack of compression - probably from a slipped timing belt. Have you checked that?
Customer: replied 1 year ago.
Have the insp cover off , how to test for slipped belt?
Customer: replied 1 year ago.
Able test camshaft sensor w multimeter?
Expert:  Juan Crespo replied 1 year ago.
You'll need to perform a compression test to see if the engine timing is OK or not. You can look at the timing belt and see if the marks align (see attached graphic). If they don't, the engine timing is off and there won't be enough compression for it to start and run. If there is spark and fuel at the cylinders, testing cam sensor signal is not necessary at this time.Also, it would help us both to know what is the car's engine code. Look for it on the rear left of the cylinder block (see attahed graphic) Best Regards.
Customer: replied 1 year ago.
Just disconnected camshaft pos sensor and it starts repeatedly . Sometimes takes a few tries. Believe this is bc sensor not hooked up and ecu trying to guess tdc to fire
Expert:  Juan Crespo replied 1 year ago.
You're deviating from an efficient diagnostic path.ECU's don't have the capacity to guess, they simply follow pre-programmed protocols. The engine will start as long as there is enough fuel, spark and compression. Now you state the engine starts with the cam sensor unplugged, something completely unnecessary, but which confirms my theory that cam and crank signal are so far apart that the PCM won't allow the engine to start with both cam and crank sensors connected.You state you already have the inspection cover off; have you checked timing belt alignment? or performed a compression test?I would like to help you and certainly don't want to waste your time or mine; if you're not comfortable following my instructions, would you like me to opt out so another expert can chime in?

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