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Tim Mohr
Tim Mohr, ASE MASTER TECH
Category: Acura
Satisfied Customers: 15969
Experience:  30 YRS EXPERIANCE, AUTO AND TRUCK,FOREIGN AND DOMESTIC, GAS AND DEISEL
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1999 Acura: wont start..Car cranks..Car has no check engine codes

Customer Question

1999 Acura 3.5 RL won't start. Car cranks and motor turns but just won't start.
No spark coming to plugs and no current in fuel injecters. Car has no check engine codes.
Here is what I have replaced uptil now. Crankshaft sensor, Ignition switch, main relay PGM-FI. There is fuel pressure so I know its not a fuel issue. Also key and immobilizer are fine.

Any suggestions would be appreciated.
Submitted: 5 years ago.
Category: Acura
Expert:  Tim Mohr replied 5 years ago.
Hi, my name is Tim, this is usually caused by a bad main relay, does the check engine light come on for 2 seconds when the key is turned on?
Customer: replied 5 years ago.
Comes on and then goes off like its supposed to. Bought new main relay from acura dealer. Still same problem.
Expert:  Tim Mohr replied 5 years ago.
and you have power comong out of the relay to the injectors?
Customer: replied 5 years ago.
There is no power in harness plug that goes to fuel injectors
Expert:  Tim Mohr replied 5 years ago.
let me check the wiring diagram, hang tight,Tim
Expert:  Tim Mohr replied 5 years ago.
there are 2 yellow/black wires at the relay, one should be hot at all times, amd one should be hot with the key on, dont confuse either of these wires with the balck with yellow stripe, can you check both these wires?
Customer: replied 5 years ago.
I see the 2 wires. By Hot u mean hot to touch or do you mean in terms off current passing thru them ?
Expert:  Tim Mohr replied 5 years ago.
they need to have 12 volts to them, one at all times and the other with the key on or cranking.
Customer: replied 5 years ago.
That's correct. I just checked.
Expert:  Tim Mohr replied 5 years ago.
both of them have 12 volts?
Customer: replied 5 years ago.
At ON position both have power. I also checked RPM signal when cranking. Its only 23 ! I suspect the new crank sensor is faulty. What do you think ?
Expert:  Tim Mohr replied 5 years ago.
the crank signal will not effect the power to the injectors, Do you have 12 volts at the black and red wire at each injector?
Customer: replied 5 years ago.

I am using a fuel injecter test light to verify whether injectors are firing.

I have my friend's Acura 3.5RL I am using as a test car. When I unplugged the Cranked sensor harness on it, it stopped fuel injectors from firing. Again I am using the fuel injector test light to verify this.

Additionally on my test(good)car the RPM signal was 237 at crank vs 23 on the car that does not start. Which leads me to believe the crank sensor is the culprit. I will replace it tomorrow and let you know.

I will also try test for 12volts at the black and red wire at each injector like you said.
Expert:  Tim Mohr replied 5 years ago.
yes, that would tell us if just the crank signal is the problem, it very well could be a defective crank sensor, but you originally said you did not have power at the injectors, so the test on the black/red wire is important,Tim
Customer: replied 5 years ago.
Not the crank sensor ): I don't have access to the car right now but I will check for 12v at each injector next(black/red wire).
Customer: replied 5 years ago.
no voltage at an injectors
Customer: replied 5 years ago.
Tim here is something I read which sounds useful since my crank signal is only 23rpm.

"For the fuel pump to start and remain running, for the ignition coil to develop secondary voltage, and for the injectors to fire, the DME computer must see an engine start signal or an engine running signal (greater than 200 RPM). When it does, it completes the circuit"
Customer: replied 5 years ago.
Relist: Answer came too late.
Customer: replied 5 years ago.
Relist: Answer came too late.