I"m having problems gettin my SR to start. i just swapped a new head onto it and the timing and everything is good. its gettin fuel, the turbo's spinning, but it wont fire up. it just turns and like every other second you can feel it start to fire up. its almost like only one cylinder is firering. could this be a possible bad ignitor chip?? what else could it be?? how and what can i test to see whats wrong??

 

A rudimentary thing would be to stick a screwdriver in the end of each coilpack and rest it against the valve cover, remove the fuel fuse and turn it over. If you see arcing between the screwdriver and the valve cover, your chip and coilpack is good on that cylinder. If you dont see a spark, you could either have a bad coilpack or bad ignitor chip. I know it's not definite but its a start.


Oh, also, you can take a multimeter to the signal wires to the coilpack. I *think* the way that the chip works is it supplies a constant 12V to the coilpack and opens a ground to the coilpack when it wants it to fire...so just see if your coilpack is supplying 12V across the coilpack (attach the red multimeter wire to the +12 wire, and the black multimeter to any constant on ground, just the engine will do), and also check if resistance across the coilpack leads goes from infinity to almost zero. This would confirm that your ignitor chip is powering your coils and giving them a proper signal to fire.

 

i wouldn't assume the ignitor chip has gone bad R34 racer is right, just try testing the coilpacks first that seems to be one of the most common problems to have also its easy to check. are you positive u r getting correct fuel?

 

yea, i'm positive it is getting fuel... when ever we tried to start it up, i could see a small amount of fuel leaking from the return line (we fixed this problem by the way) so i'm pretty sure fuel it getting to the injectors. Now how exactly do u put the screwdriver into the coil pack?? i've never tested it like that... do u put the handle side in the coil pack? or the metal part?? please explain....

 

Put the metal side of a screwdriver into the coilpack being VERY GENTLY and careful not to damage any contacts in the coilpack...do not disfigure any connectors inside or else the pack may never sit well on the spark plugs again and you get a whole load of trouble. Once you have the screwdriver in, lay it so that the handle is on the valve cover, leaving less than 1 cm of air gap between teh metal shaft and the valve cover.

An acceptable substitute would be to stick a spare spark plug in, you risk damaging things less that way.


You should make certain that you have fuel through your injectors, not just that your return line is leaking. Remove your fuel rail and get a rag. Turn the car on, the ECU should try to prime the cylinders by spraying a little bit of fuel through ALL of the injectors. Check for this and you can be sure you have enough fuel at least for a startup.

 

ok, i did the test with the screw driver on the coil packs and all 4 pacs are sparking. however i did notice that when i pulled the coil pac out of cylinder 3 that the car just turned over. before when this one was in, the car would turn and every other second the car "vrooms" like its trying to start. so this leads me to believe that the car is trying to start on one cylinder. but all four coil pacs are getting signal. where do i go from here??

 

try r34's idea about removing the fuel rail from there i would suggest testing the ignitor chip like he said. after that its getting into hard and expensive things.

 

ok, one question before i try and remove the fuel rail. do i have to relieve the system of pressure before i remove the rail? and if so, how do i do this?

 

also, i did test out the voltage goin to the coil pac and all four pacs are revieveing 12 volts. so i'll check out the fuel and go from there

 

no u dont need to relieve the pressure first

 

ok, i did R34's idea about the fuel rail. i took the fuel rail off and had someone try and start the car. and i did not see any fuel spraying from the injectors at all. also, i bought a bottle of ether and sprayed it right into the intake manifold and then tried starting it. after a few attempts the car did start up a lil, but only for like a second and it got up to about 1000 rpm's and i couldn't rev it or anything. and that was it. so now what? any more suggestions anyone?

 

OK i have heard that the ecu will not prime the engine but will only prime the pump. First off, turn the car on or try to start it. Get close to the gas tank and see if you can hear any noise from the fuel pump as it primes/pumps. If you can't, you may need to repair/replace/rewire it. If you can hear the pump then that part is cleared. You should also test for fuel pressure at the rail by installing an inline fuel pressure guage to make sure your pump is providing ample pressure...a weak spray through the injectors will not result in a healthy starting or running engine. If your pump works and is reaching proper pressure but you still cant get a clean start, REMOVE THE FUEL PUMP FUSE and crank the engine with your ear near the rail...you should be able to hear clicking as the injectors try to fire, or observe electrical activity with a multimeter. Be absolutely certain that you do not have any fuel in the system when you do this, it could be very dangerous if your engine fires up with your ear near it. Good luck!

 

Also check to see that your crank angle sensor is properly installed and oriented, and see if the readings from the CAS are what they should be as you crank the engine...there is the distinct possibility that though you are getting spark and fuel, the ignition timing is off due to poorly installed/damaged CAS and/or improperly wired coilpacks...make sure the coils are properly wired. A good spark will do you crap if its firing when your valves are open or the wrong cylinder is firing at the right time. Since your car appears to be getting fuel in the cylinders and spark (you say it vrooms...as if to start) there is a good possibility that the coils are firing in the wrong order or that your timing is severely off.

 

actually, a safer way to hear the clicking would be to just remove the CAS from the engine and rotate it by hand with the car in the "on" position (not start, but on)...you should hear clicks from each of the four injectors as you turn the CAS's shaft. If you're getting a click from each injector, and a spark from each coil, then you can narrow your problem down to improper timing or improper wiring of the injectors/coils.

 

ok, now back to the whole ignitor question. i ran tests on it, and here are my results. the power going INTO the ignitor chip at all four pins was at 12v for each of the pins. now, the power LEAVING the ignitor goin to the coils was less than 1v for each of the 4 pins prior to cranking. and when i cranked the motor, the voltage stayed the same at around less than 1V. is this correct? shouldn't the voltage leaving the ignitor be at 12V while the motor is being cranked? could this be my problem?