How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Matt Your Own Question
Matt
Matt, Engineer
Category: Saturn
Satisfied Customers: 20615
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
12772297
Type Your Saturn Question Here...
Matt is online now
A new question is answered every 9 seconds

Car will crank and but will not turn over. it sputters with

Customer Question

Car will crank and but will not turn over. it sputters with the help of starter fluid. car ran fine yesterday but will not turn over today. 2002 Saturn S-Series.
Has gas and battery is good. checked plugs and although not new are okay.
Submitted: 10 months ago.
Category: Saturn
Expert:  Matt replied 10 months ago.

Hello

1st check for spark by removing one of the spark plugs and plug it back into its lead 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

Also its worth checking that the electric pump that feeds the injectors is working correctly, it should run for a few seconds then switch off when you first turn the ignition on. If you remove the filler cap to the fuel tank and listen inside while your assistant flicks the ignition you should hear it clearly

If the connections to this are corroded or damaged then the pump could stop at any time. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse, ideally measure the voltage at the pump and check its getting 12V.

You should be getting around 3 bar measured at the injector rail check to see if the plugs are getting wet indicating fuel is flowing – if not and the injectors are opening then there’s a problem with the pump or the filter or even the pressure regulator

Expert:  Matt replied 10 months ago.

Hi

do you still need help?

Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. I am only paid for my work on this question if you rate my answer, using the star system at the top of the screen. Please do not forget! Thank you