mx265 Posted May 8, 2012 Report Share Posted May 8, 2012 Im new here, not sure if this is the place but I my daughters volvo has tortured me for the past four weeks. 1999 Volvo S70 GLT 153k She hit her radiator on a parking curb, overheated and blew an exhaust valve. I replaced the radiator and it blew white smoke. It was running fine even with the blown headgasket. The blown valve made it run rough, but it started and ran. I sent the head out and had had everything replaced. Put it back together by the book...?... Has spark in all 5 cylinders... compression is 140psi in each cylinder. fuel pressure is 55psi at end of rail. Lastly I checked the injector pulse... None. checked the plugs..they were wet but not fouled. While I had it apart I replaced all vacumm hoses, radiator, radiator hoses, oil seperator, 5 fuel injectors, ABS module, Oil fill Cap, Coolant Cap, battery is 3 months old. FYI- I used a jack with stands to lift the vehicle to disconnect the exhaust and turbo from underneath. I thought I might have activated a theft device??? Its all there, It wants to start, cranks forever and is hooked up to a battery charger like its life support. I have constant negative on one side of all 5 injector wires but no pulsing on the other with the engine cranking. Anyone have an idea. I double checked everything. every plug is connected. All fuses are good... not sure about relays. Full tank of fuel. What should I check next? Thanks in advance. Link to comment Share on other sites More sharing options...
burnout8488 Posted May 9, 2012 Report Share Posted May 9, 2012 Faulty cam or crank position sensor would most likely eliminate spark. The cam sensor is located on the back of the cylinder head on the driver's side, crank sensor at the bottom right of the cylinder head facing down into the transmission. Both connectors for these sensors are under the intake manifold on the right, above the starter motor. Try unplugging one or the other and see if the engine's behavior changes at all. Also try unplugging the MAF as well as a diagnostic tool. A 99+ won't run with the MAF unplugged, but it might stumble, which would lead you in the right direction.**The MAF, using it as a diagnostic tool On that note, if you plug in an OBDII scanner, get any codes? Link to comment Share on other sites More sharing options...
Keaton85 Posted May 9, 2012 Report Share Posted May 9, 2012 Do you have a check engine light? Also why do you think you have a burnt valve? since you wouldn't even come close to 140PSI of compression if the valve was burnt. My bet is like stated above, cam pos. sensor.... I would buy a known good used one for cheap and swap it out. Link to comment Share on other sites More sharing options...
Dan A Posted May 9, 2012 Report Share Posted May 9, 2012 In my experience a bad cam sensor will not cause a no start on ME7, like it does on the earlier models. It will cause an extended crank when starting though. Crank sensor would I think. How old is the fuel? Why did you change the injectors? Ignition switch/immo? Bad ground? Link to comment Share on other sites More sharing options...
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