I've been trying to get my 1992 LX wagon (5-speed, 196k miles) to start for more than a month now, and I'm not sure what do to next. Would really rather not have to tow it somewhere and pay to get it fixed, seeing as how I've already invested ("wasted"?) lots of time trying to diagnose and fix it myself... and done most of the parts-swapping I think the average shop would try anyway.
Hoping one of you highly experienced Honda people out there has an idea of what to try.
The car just up and quit starting. It went from running/starting 100% of the time to not at all one day in my driveway (it didn't stop while driving and leave me stranded). It always cranks and turns the engine over, the battery is strong, but the CEL never turns off after turning the key to ignition position and I do not hear the fuel pump priming. Doesn't matter if it's hot or cold; the car consistently refuses to start (and the CEL always stays on and the fuel pump never primes).
I've used these resources to try to determine what the issue is:
http://techauto.awardspace.com/ecu.html
http://www.tegger.com/hondafaq/startproblems.html#top
Here's what I've checked that looks good/normal:
This is what I've found that is NOT normal:
So, the million-dollar question is: What is causing wires A25 and B1 at the ECU to read less than 1V with the key at ignition position, rather than the 12 volts they should be showing?
The only components left to replace that *might* be the culprit are the coil, the TPS on the throttle body, and the MAP sensor on the throttle body (I normally wouldn't suspect those except that they're shown as potential issues in the first wiring diagram gif below).
The weird super-low voltage makes me think some wire is shorted, but which one?? And if there were a shorted wire, wouldn't a fuse be blown SOMEWHERE? Again, all of the fuses are good in both fuseboxes. And I mean ALL of them... I've even checked the fuses that don't have anything to do the engine, because I've run out of things I know to check.
Thanks in advance for the help!
Images for reference:
Hoping one of you highly experienced Honda people out there has an idea of what to try.
The car just up and quit starting. It went from running/starting 100% of the time to not at all one day in my driveway (it didn't stop while driving and leave me stranded). It always cranks and turns the engine over, the battery is strong, but the CEL never turns off after turning the key to ignition position and I do not hear the fuel pump priming. Doesn't matter if it's hot or cold; the car consistently refuses to start (and the CEL always stays on and the fuel pump never primes).
I've used these resources to try to determine what the issue is:
http://techauto.awardspace.com/ecu.html
http://www.tegger.com/hondafaq/startproblems.html#top
Here's what I've checked that looks good/normal:
- Confirmed that all of the relevant underhood and underdash fuses are good
- Jumpered the diagnostic wire hanging out under the passenger side dash; CEL stays on solid, no blinks/codes
- Replaced the ignitor; the main relay (twice, in the case the first non-OEM replacement relay I bought was bad); the entire distributor, which replaced the ignitor again; and the ECU
- Confirmed that the main relay clicks (by feel) when I turn the key to ignition and back off
- Confirmed that the timing belt isn't snapped
- Confirmed that the distributor rotor turns when cranking
- Removed, sanded and cleaned, and applied anti-oxidation contact grease to the multiplexed ground terminal on top of the thermostat housing
- Checked the connections to the distributor (by unplugging them and reconnecting them... they look totally fine / clean)
- Confirmed that there's 12v on the big fat black/yellow wire to the coil
- Confirmed that there's 12v on the black/yellow wire that feeds the fuel injector resistor box
- Confirmed that the fuel pump itself spins/hums when I apply 12V and ground to its contacts directly (I cut a hole in the unibody of the car to do this)
- Confirmed that all four of the ground wires at the ECU (A23, A24, A26, and B2) are good
This is what I've found that is NOT normal:
- Checked for voltage at the two wires to the fuel pump right after the key has been turned to the ignition position... there is none
- Checked for spark with the engine cranking... there is none
- Pulled a spark plug and checked for signs of fuel delivery after the engine has been cranked over... there is no smell of gas, the spark plug tip is bone dry (makes sense, considering there's no voltage at the fuel pump)
- Checked for voltage at A25, B1, and D1... there's 12 volts at D1 (the feed wire from the battery) but A25 and B1 only show 0.7 volts with the key turned to ignition
So, the million-dollar question is: What is causing wires A25 and B1 at the ECU to read less than 1V with the key at ignition position, rather than the 12 volts they should be showing?
The only components left to replace that *might* be the culprit are the coil, the TPS on the throttle body, and the MAP sensor on the throttle body (I normally wouldn't suspect those except that they're shown as potential issues in the first wiring diagram gif below).
The weird super-low voltage makes me think some wire is shorted, but which one?? And if there were a shorted wire, wouldn't a fuse be blown SOMEWHERE? Again, all of the fuses are good in both fuseboxes. And I mean ALL of them... I've even checked the fuses that don't have anything to do the engine, because I've run out of things I know to check.
Thanks in advance for the help!
Images for reference:
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