sorry for the double post......went to go out an start the car to go to work........but now i think the ecm might have bit the bullet due to the rain that got into the car.........In the main relay Pin #8 is ECU controled ground and is supposed to ground when u turn your key on(II) for two sec then unground. When u turn ur key to start the ECU senses the engine is turning and reapplys ground............Pin number 8 is UNGROUNDING when i turn key to start.........im trying to diagnose to see if my injectors are even comming on when #8 is grounded or if there is a fuse somehwhere im just not seeing........im trying to figure out why when the key is first turned on it is grounded but once i start to crank the ECU is ungrounding ............anyone got any ideas here

 

Could be a couple of other things besides bad ECU. ECU's don't fail that often. But if your ECU got water in it (take it out and open the covers) it's likely bad. Another way to check for signs of life from the ECU is to try and pull codes. With the test jumper in place the CEL should blink out codes, or stay on steady (as opposed to turning off after 2 seconds) if there are no codes stored.

The key switch (or substitute) could be bad, so the ignition/ECU system gets power in on but loses it in start.

The ECU may not be getting a signal from the distributor, because distributor is bad, or it's actually NOT turning because the timing belt is stripped.

Loss of power or ground to the ECU system, there are a couple of different power circuits involved some with the main relay some not. And check the ground wires on the engine at the thermostat.

I've never tried to bypass the main relay but there does seem there's some feedback where the ECU can tell if the relay has closed or not. It's possible that if you don't throw all your switches in the right sequence to simulate stock operation, the ECU may refuse to work.

 

.......lemme start from begining when i get in car and i turn key to ON(II) flip switch1(Injectors) on then i flip switch2 (fuel Pump)on .at this point Switch 1 and 2 are illuminated and i hear the pump whirring..... after about 2 or 3 sec i will turn the key to Start........this is where the (i assume)#8 pin ungrounds and i lose power at switch1 aka no injector pwr and thus no start ........how do i find out if i am recieving pwr to the Injectors w/o having to pull an Inj out an spraying fuel all over. I currently dont have a voltmeter or test light cause they both got stolen when my toolbox got hijacked. I know u can usually hear clicks when the engine is running but will they click during starting ??

nvrm i know its not the ign switch cause #6 pin isnt powering anything when i turn to start.........its basically wired directly to #8 the same way it is in the relay,,,,, my 12v sources of power for the two switches are Pin#1 (batt+, for inj power aka sw. 1) and Pin #5 (12v+ comes from ign switch, On(II) position aka sw. #2)


Edit: I have narrowed my problematic intermitent no start condtions down to the lack of spark .........up to this point i was thinking it was injector related but today i had a friend helping me and found out that when it wont start i am getting fuel and the injectors are comming on but there is NO SPARK.....checked my cap it looked ok but had some what looked like oil on the inside of the cap im thinkin the person who installed this cap....possibly the mechanic used motor oil to get the gasket to "stick" by coating it with oil .......other than that i didnt see any oil leaking from the distributor or anywhere else...do u guys thing thats what might be causing all these problems.......ganna replace the cap tomorrow .....after that ganna go after the coil if it still wont start.

 

bump for an answer

 

Motor oil will get into the distributor when the shaft seal is bad. You would also see oil in the bottom half of the distributor, the metal part closer to the engine. Also do not run without the plastic separator plate in place below the rotor. Without it sparks can jump to the low voltage parts and cause damage.

You really need to own a voltmeter to track down electrical problems. Check for voltage reaching the distributor, there should be battery voltage on both small terminals of the coil.

Leave the cap off and hold a grounded test wire near the output spring on the coil, and crank. If you only get small yellow sparks the coil is almost certainly bad.

 

ok cool thanks ......im ganna be getting a multimeter and test light this wednesday.......i replaced the cap today ..........so far ive had NO more problems....i will keep yall updated thanks for all the help

 

........this morning wont start.......where is the ICU in the car...tried locating it last night couldnt find it ......ganna change the coil and see if that will help

 

There is no "ICU". The ICM or Ignition Control Module (also called the "igniter") is inside the distributor next to the coil.

 

......whatdya think should i just replace the whole distributor???
if i just start replacing the parts inside its ganna end up costing me more than the price of the whole distributor

 

Working sometimes and not others suggests a bad connection somewhere. You really should test some voltages when it is not working before going out and buying more parts.

ICM's can fail when hot, then work again after cooling off. Dead coils usually never work again after they quit.