» » »

Toyota Q&A

Ask Your Question

1990 Toyota Corolla Question: My car went dead at 45 mph on the highway. How can I diagnose problem?

 

Question

Dubbld, 1.6L 4 Cylinder, Memphis, TN, February 17, 2012, 07:22
 Rookie

I've done some work on car, I replcd timing belt 3 yrs ago, and it has run great since. I had weak spark, so I replaced distributor, cap, plugs and wires. Car does not start. I have put engine to TDC on #1 prior to inserting dist into engine. Is there a TDC for intake and exhaust? i am following Haynes manual. Will I need a timing light?

2 Answers
Flag This
  • Answer #1

    patrick mannion from Greg Solow's Engine Room, February 17, 2012, 08:39
    Profile_thumbnail
     Master

    First verify valve timing is correct, crank pulley and timing cover mark will align at tdc at the timing lower cover and the cam timing marks will align with marks but you must remove upper cover to inspect, if they don't allign rotate engine 180 degrees and see it marks now align. If the do remove the distributor cap and ensure rotor is pointing to number one plug wire. Amusing that is correct, you could check compression to verify things are OK, Check for fuel and spark on cranking. Check for fuel pressure (you will need a fuel pressure gauge and look up the specified fuel pressure for your vehicle). On your car crack open the 17/19mm banjo bolt at the fuel rail and get a friend to crank over the engine to see you have adequate fuel volume (you should have approximately 1 pint of gasoline in ten seconds of cranking). Off course take proper precautions as gasoline is highly flamable. Next "listen" to the fuel injector. Using a mechanic's stethoscope (or use a long screw driver placing the handle end up to your ear place the metal tip end of the screwdriver against the body of the fuel injector), get a friend to crank over the engine while you "listen" to the fuel injector listen to each injector at the same point of the injector body. You should hear "click, click, click" as the injector is electrically opened and closed by the computer. If the injector is not being triggered you will not have fuel getting into the engine's cylinders. Disconnect the electrical connector at the fuel injector with the ignition key in the "on" position, (next position after the accessory position) you should have 12 volts at one of the two wires at the injector. This true for most vehicles but you need to consult a workshop manual for your vehicle to see that this is true for your vehicle. When the engine is running the second wire at the injector gets (triggered) grounded by the computer in your vehicle many times a second controlling exactly when and how much fuel gets injected into the engine.
    Check for ignition spark. Use caution when checking ignition spark firstly it provides very high voltage (about 15,000 to 40,000 volts) but it is low amperage, it can give an unexpected shock but is unlikely to kill anyone, secondly the spark produced can ignite any flammable gas or liquid (for example gasoline or the gaseous vapors of a lead acid battery). Remove the spark plug wire, place an old spark plug with the gap between the electrode and shell of the spark plug "widened" to about .060" or .070" of an inch. Firmly ground the spark plug shell to a good engine ground. Hold the spark plug wire or coil with an insulated pliers and get a friend to crank over the engine while you watch for a pulsing bright spark jumping across the spark plug gap. Look on Youtube for a video on "Check for spark" or Check for ignition spark" I am sure someone has posted a good video clip.
    There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online

    Flag This
  • Reply

    Dubbld, February 20, 2012, 10:17
     Rookie

    It's alive!!!!!! The 'yota is back in business. Thanks for the detailed answer. This is a great community for sharing information. I really appreciate all the help.

    Reply
    Flag This
  • Answer #2

    only1bigcat from Up Front Automotive Service, February 17, 2012, 11:46
    Profile_thumbnail
     Enthusiast

    well you still could be out 180 degrees with your dist. You needed to make sure that the piston is at TDC on the compression stoke. Have you check to make sure the cam is turning ? This is easy remove the oil fill cap and look inside at the cam while some one cranks the engine. If it doesn't move them the belt you put on 3 years ago could have a problem. Timing belts can be temperamental. If something like a idle pulley bearing go bad it could damage the belt. If they are not adjusted correctly then there life span will be greatly reduced. I would also check fuel pressure. You need the basic 3 things to have a running engine. 1. Fuel, 2. Air, 3. Spark(at the right time)
    One of these are missing

    Flag This
  • Reply

    Dubbld, February 20, 2012, 10:22
     Rookie

    The car is back from the dead! Thanks for your help. I double checked the cylinder, checked for the compression stroke, all looked good. Confirmed no fuel issue, and was getting weak spark before, after I put in new distributor spark looked good. Couldn't crank engine fully due to weak battery. Replaced, fired right up, set timing at 10 deg BTDC. and we are rocking. Thanks for being so free to share info.

    Reply
    Flag This
Answer Ranks