As described in previous post, car was running great and quit abruptly while driving. Will turn over but will not fire. Had it towed to the house and have done the following checks:
OBDII Scan - no codes
Fuel pressure - steady at 40 psi while attempting start. Holds at 40 psi indefinitely. After disabling fuel pump, observed that the fuel pressure drops as injectors fire while attempting start. Attempted to start using starting fluid and would not fire.
Compression - 160, 165, 165, 170
Spark - observed each(new)plug firing by grounding against motor. Strong yellow/white spark. Replaced coil just in case. Plugs appeared wet with gas when removed.
Spark timing - used timing light to verify #1 cylinder firing at or near TDC
I’ve been doing my own work for 40 years and this is the first time I can’t figure out why an engine won’t run. Last chance for suggestions before I get it towed to a real mechanic.
Tester? OK? Other diagnostic wizzards?
W/ all of the stuff you got last time (and I don’t know what it all was) and 40 years I probably can’t tell you much - but I would regard a yellow/white spark as a real problem - as far as I know it should be strong and blue. Did it change at all after the new coil? Add to that the fuel soaked plugs & I would call it an ignition problem.
You should also check the crank position sensor - can probably find procedure in Autozone’s online manuals
Just on the chance your cylinders are “washed out” from too much fuel resulting in no compression,go ahead and squirt some oil in the cylinders (approx 1/4oz) see if she fires up.
Yeah, I was suspicious of the spark color too. Was expecting blue spark. That’s why I changed the coil just guessing. Regarding the crank position sensor, I would expect the computer to show a code if that was the problem. I would also expect the spark timing to be off. You may have something, though. I would have changed the crank position sensor too, but according to books, I need to remove exhaust manifold to get to it and I didn’t feel that ambitious today. Thanks for the suggestion.
Is it possible to use a timing light to see if #1 cylinder is firing on time? The crank sensor and cam sensor should be working together to ensure proper timing, but if a reluctor wheel slipped, it may be grossly out of time. Just a thought, since you checked most everything else.
Yes, I checked #1 with a timing light. It was OK.
What was the ignition timing with the timing light? Near 0 degrees?
You might get a stronger spark if you disconnect the lead from the "noise cancelling capacitor, coming off the connector, on the ignition coil. It could be bleeding some of the charge off.
Is the ignition coil receiving 12 volts during cranking (at Start position)?