Replaced the timing cover gasket, (gushing oil) and found reluctor wheel slightly bent, so replaced that as well. Car ran great when pulled in garage before repair. Has been down a month and desperately need it running for a second car before new baby.
Tried to start after repairs, and found I had a crank no start issue.
P.A.T.S: = OK (Light flashes; then goes steady at key on)
Starter = OK (strong and steady crank)
Fuel:
Fuel Pump = OK (primes freely and 54 pounds of pressure KOEO)
Injectors = OK (getting voltage and being pulsed)
Cam Sensor = OK (injection pulse present)
Spark:
Battery = OK (12.34 volts at battery)
Coil = OK (white spark at plugs when tested)
Plugs = OK (new motorcraft)
Crank Sensor = OK (ignition spark present)
Timing:
Reluctor Wheel = OK (missing tooth lines up with TDC)
I recently diagnosed a weak spark by touching the spark plug wire. It didn’t hurt as much as it should have. No need for fancy tools! The spark can be a long high Voltage spark, but if it is weak it won’t be as bright and won’t hurt as much.
Bad gasoline could also be something to check, but a month isn’t that long.
Alright, so I remembered on these cars if the CEL stays on during cranking that means bad crank signal. So i went out into a now cold garage and cranked it. (went off during crank)
It actually started sputtering and was trying to start but I smelled fuel after about 5 seconds and stopped. Pulled the fuel pump relay and cranked again and until the battery suprisingly ran down (been on a battery tender) it almost started.
So temp change and letting it sit. So you guys may be psychic. Checked voltage at the coil feed and 4 out of 5 terminals measured 12.1 volts. But this kinda shows weak spark or faulty CST or MAF dive?
You found a slightly bent reluctor wheel and replaced it. The car has not started since. Doesn’t the relucrtor wheel send the timing signal That is where I would be looking.
I like to start with the low tech divide and conquer approach. Have you tried spraying some starting fluid into the intake to see if it will attempt to start then?
Yes, really. Started fluid is basically very easily combustable ether or similar so if it starts and runs while spraying may indicate poor spark or mixture.
Mixture is controlled by the cam sensor and a myriad of other sensors that are verified good. The pulses on each injector were at time when tested. The post noone seems to be reading above shows when fuel was cut the available spark and compression almost started the car.from the remaining fuel in each cylinder. Plus the smell of gas before. This all points to weak spark and not a fueling issue. So respectfully, no it isnt. Im working 16’s this week and wont have time to test till tomm. If m wrong, i’ll eat crow ITT, if not at least i’ll have a fix for the record for others to find.
Rail pressure and injector electrical signals are not definitive evidence the injectors are actually spraying gas into the cylinder. The smell of gas and an attempt to start after the removal of rail pressure does not necessarily mean there is no/weak spark. The injectors could be marginally working and dribbling gas into the cylinders which would not readily combust until enough of it had dissipated. So the starting spray test is still a viable diagnostic step in determining what is going on. I only mention this because I myself have blazed past potential contributors assuming they could not be at fault based on assumptions. I hope you’re right and on the right path. But the extra steps needed to gain more confidence are relatively inexpensive and easy to do.
I know nothing about this system so I probably shouldn’t even bring this up………but I’m going to.
Since the only part besides a gasket that was replaced was the reluctor wheel I’d start there. Is there any possibility it was installed wrong? Maybe at TDC on the exhaust stroke? Backwards? Just throwing out ideas, don’t crucify me.
I’d guess white spark means coil is ok. Usually I see a blue-ish/white spark when I do that test on my cars. But I’ve only had problems with spark preventing starting when there is no spark at all, or if the spark is noticeably red or orange colored. OP, suggest your first diagnosis, is the fails to start caused by no spark, or no fuel? Given what you say, seems you have both spark and fuel though …hmmm … some ideas
Maybe the fuel pressure is good, injectors are being pulsed ok, but no fuel is coming out of the injectors.
Maybe cylinders are flooded with fuel. This can happen when testing other systems in the car. I had it happen on my VW Rabbit years ago, crank ok, spark ok, fuel ok, wouldn’t start. Suggest to remove spark plug, does tip look wet? If so remove all the spark plugs and let it sit overnight for excess fuel in cylinders to evaporate.
Your battery voltage is too low at 12.34 volts. Should be about 12.6 volts. That doesn’t seem like much of a difference, but battery charge isn’t a straight line relationship to voltage. Even slightly less than 12.6 volts means significant undercharge. Disconnect & charge battery at low current setting (2 amps or so) overnight using shop battery charger, see if that helps.
Maybe spark good, but it is occurring on exhaust stroke rather than compression stroke.
What happens if you spray a little starter spray (ether) into the air intake before cranking?
Computer diagnostic systems are great but they can only test what their programmed to test and I suspect that everyone of us has been fooled by a cracked wire, corroded connection, clogged tube or a marginal coponent.
So when the computer doesn’t give a fix, time to go back to basics, “Air, Fuel Spark”, use logic and carefully check everyting. “Hmmm, no air seems to be getting through let me check that intake … so how did Micky Mouse get in here!”.
You are 100% right on those being possibilities. I just was hoping that with a fully charged battery, spark would dramatically decline, or improve. But during testing today I found out I am getting weak spark, but the “coldest” was all orange, while the “hottest” was purple. In one test with one plug unplugged while testing another, it increased the temp a bit but only proved the ground is a bit dirty to the coil. I was hoping for a dead coil. A clear path forward. Still, it proved the coil needs replacing I guess. Next is combustion fiddling. /consumes crow
Well you have to remove a lot of components to change the cover but yeah just gaskets and the wheel. Its possible but that would mean 180 out on the wheel and hella backfiring when cranking id think?
