Weird starting problem

It was the CKP! Probably more the connector than the sensor, though. Man I hate it when a part decides not to completely fail! But it does sound like you're managing to turn lemons into lemonade by getting the recall stuff fixed.

Flandry said:

It was the CKP! Probably more the connector than the sensor, though. Man I hate it when a part decides not to completely fail! But it does sound like you're managing to turn lemons into lemonade by getting the recall stuff fixed.

Click to expand...

The CPS signal is not used during start.

I was also pretty sure it was the CKP and mentioned you must either scope it out or watch it with a good scan tool. Without those tools you would never find it, so don't feel bad bringing it to the dealer. If the CKP is really bad, your check engine light will not go out. In a no start situation, be sure the check engine light stays on until you crank, and goes out during cranking. A partial signal will not extinguish the light, and sometimes not set codes. However, you only may be firing one or two plugs or the plugs fire at the wrong time. The computer can't really detect intermittent CKP until you are driving at high speed, then the misfire monitors are activated. Problem is you never get started .

The CKP is a dynamic signal that must be dead on accurate for the car to run properly. The Hanes static test is useless, because if the sensor is shorted THe computer will keep the CEL on. www.obd-2.com software will allow you to graph the Ford PIP(Profile ignition pickup) parameter as you are cranking. It will become pretty apparent if there are any issues. I don't know anything else (unless you want to spend a few grand) that would be able to track down something so subtle. The other option is a labscope.

In the early 90s Ford recalled many cars for bad TFT pickups on the distributors. The TFT module was near the engine heat and would deteriorate. Those older cars relied on that unit to compute PIP, and when it fails you have everything from no starts to stalling...

Yeah-don't feel bad Al.
The only way you could have troubleshot this effectively would have been to shotgun it by replacing parts. And I know you despise doing so.

Sometimes though,as low tech as it sounds, the redneck way works.

The way I look at it-if I waste a couple of new parts looking for the bad one, I have still beaten the dealer at his game.

Oh well, those recalls needed sorted anyway.

And-you got that old oil out of there-

just messin'

Atleast he didn't change the plugs like I said. That would of been atleast one broken knuckle.

I'll have to remember this one if my truck doesn't start.

Who knows, someone may buy that used motor oil on ebay.

Well I got the truck back and it runs perfectly ( except with the dog like stock computer tune that I restored before taking it in ).

I did get 3 freebies ( recalled items - a $167.26 value ):

(1) new multifunction switch
(2) Driver's seat recliner bolt
(3)Cruise control deactivation switch

The total bill with the CKP sensor and labor plus all the diagnostic time was just $456.47.

jtsmith said:

And-you got that old oil out of there-

Click to expand...

And I am sending you the bill.

just messin'

Click to expand...

Me too

aldive said:

The total bill with the CKP sensor and labor plus all the diagnostic time was just $456.47.

Click to expand...

All things considered, that's actually not too bad. Subtract the cost of the part and the recall items and that ends up being equivalent to about 3 hours of time.

Alright! glad you got your explorer ready again to be getting another 30mpg

Flandry said:

All things considered, that's actually not too bad. Subtract the cost of the part and the recall items and that ends up being equivalent to about 3 hours of time.

Click to expand...

Price is fair. That CKP can be a very hard intermittant to track down. It is twisted wire harness(like a computer network cable) where it may boil down to touching the wire in places all the way to the computer and watching the waveform with an expensive scope to see where the issue lies. They may even need 2 guys, one to crank, one to watch the scope and play with the wire.

It also shows how valuable this board can be if it does help someone solve a problem.

Well this is a very informative. I plan to follow it as I try to diagnose my dead truck.

aldive said:

Changing oil without being able to drive up on the ramps is a pain in the rear.

I had to jack it up and use jack stands.

Anyways ….

Two new oil filters and 6 quarts of Amsoil 0w30 ( Signature Series ) and just as I predicted, the truck still does not start.

Damn do I hate wasting perfectly good 18k miles old oil.

Click to expand...

Didn't waste it at all. Put it back in the motor. Reused the Bypass filter but did use the new full flow filter and its 1 quart of all.

I want to go 30k on this oil.

if i read correctly you have a scan tool. any good scan tool will let you look at what they call "pids" or "live data" every scan tool has a different word for it but it basically lets you look at sensor readings on the scan tool screen. if this were my truck i would hook up the tool koeo and find the pids or live data or what ever they call it and scroll down until you see the crank sensor readout then while looking at the crank read out turn over the engine you should see some numbers relating to rpm's this number should make since like 250 rpm's or better if its less than than the crank sensor isnt sending the signal to the ecu to turn on the spark or injectors and here lies the problem if that is ok look at all the other readouts and make sure that every thing makes since. like since the truck has just been sitting you should make sure that the intake airtemp and the coolant temp are very similar. thats all i can think about for now post up what you find and ill help more if i can.

guess i should have read further but hey at least i was right well if any one else reads this hopefully i helped some one.

only been a member a short time. Had this same problem start about 3 week ago replaced the cps last week and so far no more problems. thanks for all of the great info. If this easy repair solves my problem, probobly save me a good $400. cps at auto zone $42 45min removal and install.
thanks

My fuel pressure is fine; thanks for the idea though.

Wow, awesome post with alot of good info for knowledge and troubleshooting. I have similar problems and will get a CPS tommorrow to see if that is it, I will post problems findings for others that I found to help others.

I drove the car home after work with no problems. Came out about 4 hours later to take the kid to karate and it just cranks but wont start. Checked the fuel side of the house first and everything seems OK. Fuel pump relay is good (even switch the relays in the fuse block in the engine compartment to ensure), had power at a pin where the fuel pump relay goes with no key, had power in that pin and another with the key ON, had power at the fuel pump/fuel sending unit connector on the framerail, pump kicks on for 3ish seconds when the key is turned ON, and all related fuses relays checked out fine. INERTIA switch wasnt triggered either. Now I didnt test the fuel pressure yet, but below will explain why I havent yet.

I checked the camshaft postion sensor and there is 0 volts going there, pulled the sensor and checked for A/C with a mulitmeter at the terminals on the sensor while passing a metel object on the back side and it works

Checked for spark next and I got none (I used an inductive timing light and the good old screwdriver method on 3 different wires), I checked power going into the ignition control unit and there was none (went ahead and checked all pins with the eninge ON), checked the crankshaft postion sensor next and there was 1.5 volts with the engine on only and unplugged. It started to get dark tonight so i couldnt check for A/C at the sensor while cranking the engine.

Anyone care to throw 2cents to me before I do buy a Crankshaft postion sensor. And I am not hijacking a thread, just thought I keep it alive for others with the great info here.

VERY similar situation in my wife's truck right now... It just started.

It has 100,000mi on the truck. It is has been DEAD reliable towing and driving. It is my wife's car.

Starts fine 95% of the time. Randomly(a lot when it has or is raining) it simply will not start. It turns over and simply will not fire.

Wife has now been stranded and work(school teacher so she can get ride home). Last time this happened I am thinking dead battery. No biggie. Grab a battery(optima) and head over with wife. Car fires right up on the battery in the car. Check battery date and replace with new battery just in case.

Same thing today. Just won't fire. I tell Jenny that it is a starting issue. Try starting and giving it some gas. It finally fires and 'smells like gas' she says but it is running like a champ now and it was driven home.

Where to start on this? I am a certified BMW technician and build BMW racecars so I can get in there and find it out myself but I am guessing this is something common.

wow, mine sat for a day and now it starts. All I did was pull and unplug stuff and it starts up fine now. Last thing I checked was the crankshaft sensor and i just unplugged it and took it out and cleaned it.

BWM tech,,,,my other car is a 91 VW jetta.

Guess I run through the engine sensors and unplug and clean up the contacts.

had the same issue turned out to be the crankshaft position sensor pretty easy to change