My 87 N/A Auto was driving fine i had to move another out of garage so i had to drive my RX up the hill a little small slope in back yard later that night i rolled it back next morning car would not start rotors would turn but no start. i am getting gas cause i can smell exhaust at tail pipes and can feel at the fuel pump. i have checked my CAS it reads fine on multi-meter i checked relay behind trailing coil packs fine... i checked voltage at leading coil pack connector 6.64 volts and it is sparking but VERY VERY weakly trailing is nice and strong when checked battery is at full charge i am at wits end and wife is wanting me to just sell it or part it out.... PLEASE HELP STOP HER.....

 

Compression test

 

On the LEAD coil assy the black/yellow wire on the two wire white connector should have battery voltage. The other wires voltage is irrelevant.

 

the battery reads 12.7 volts the black/yellow wire reads 6.64 volts is there somewhere inbetween that could drop the voltage.. like the computer maybe

 

The path is .......from the EGI INJ fuse in the engine compartment.......through the MAIN RELAY......to the coils (both), then to feed the Solenoid Resistor Package then all four fuel injectors.

The wire color b/t the EGI INJ fuse and the Main Relay is some other color than black/yellow.

Could be the contacts inside the main relay. Maybe.

Or a fellow on this forum had a problem with his condenser that is connected to that black/yellow wire. Its UNDER the Trail coil assy and is a black square looking device about 1/2 by 1/2 inch. Just unplug that outfit and see if the voltage rises on the black/yellow wire at the lead coil assy. If it does not, then that is not the problem.

YOu could try to isolate the problem by eliminating the fuel injectors. Pull the large, five wire plug off the solenoid resistor that is located under the afm and is bolted to the right fender. It has a aluminium cover on it. If you disconnect that plug and the voltage rises, your close to what the problem is.

If you don't know what a solenoid resistor package is, then do a search on this forum. PUt in SOLENOID RESISTOR PACKAGE AND JPG and for a name put in HAILERS. You should have serveral threads to look at and in one or ten there is a jpg of a SOLENOID RESISTOR PACKAGE.

Another thought.......when you measure the six volts at the black/yellow wire, go immediatly to your battery and see if the battery is being pulled down to six volts at the same time. If so, then it's a batt problem .....maybe.

 

Well i unpluged the solenoid resistor package nothing changed i also checked the battery under a load no drop in voltage a friend of mine said that it could be the ECU not sending the right signals so i am trying to get another ECU to test out on the car..... everything else in car works fine.. radio, headlights, wipers, fans, etc. etc.

 

If the small, white, two socket plug at the Lead coil assy is pulled apart, and the black/yellow wire has six volts, it is not the ECU.

That black/yellow wire is the same circuit that feeds the trail coil assy also. The black/yellow wires at both coil assy are spliced together. If one reads good, then the other should read good.

The ECU puts a ground on the OTHER wire in that small, white, two socket connector at the Lead coil assy. The ECU does not feed that black/yellow wire and can have no influence on how much voltage is on that black/yellow wire

Maybe your not actually reading the black/yellow wire with the small, two socket connector apart? Maybe your reading on the coil assy???? instead?