Starting Issue

[frickea86]

Hello all, the explorer decided to start giving me starting issues. I've been working on this problem for about two weeks now.

The problem is intermittent and seems to vary depending on the weather conditions. The starter and fuel pump are priming fine but as soon as I try to turn the truck over nothing. Seems like no spark or no fuel is getting to the engine. It turns over no problem but thats all it does, nothing happens but the starter turning the engine over. No small hiccups or rough idle and no signs of ignition.

It will start though after a dozen tries of cycling the key off and on. After getting it to start once she runs fine, I have no problems starting it after and it fires up every time there after, till I let it sit for a while and moisture sets in.

What I've done to narrow my suspects down is look at all relays and fuses, checking to make sure no corrosion is present. Meaning, I've clean just about all connections relating to the PCM, and Fuel Pump. I did purchase a fuel pressure gauge to test the vehicle when the problem arises again.

What I think it is or could be:
1. Fuel Pressure Regulator
2. Fuel Pump
3. Electrical Issue

I think its the Fuel Pressure Regulator because the last time it did this to me it was making a howling noise. I don't really think its a fuel pump issue, I'm not getting any weird shudders or stall outs.

Another thing is when I do get it to start I don't smell a crap load of unburnt fuel. I would think after trying to start it after a dozen times the cylinders would be loaded.

Please let me know what you guys thing, I am willing to test anything. Thanks

 

[aldive]

What is the fuel pressure with the key on?

 

[frickea86]

Al, I knew that was going to be the one of the first questions. I have yet to try out my new gauge because the wify has the truck right now. I will know tomorrow at the earliest.

My question is, what should it be around. I have read in the ford manuals some where around 40psi? I will have to look at them again, its been a while.

 

[lorenambrose]

Crankshaft position sensor or Camshaft position sensor did the trick for me. I had the same problem.

 

[frickea86]

Just to state some more information. Its not the fuel filter, that was just replaced and I never run crappy gas that I know of. Sparks and wire have all been changed about 50k ago and are in really good shape. My engine bay is always spotless and the sparks are looking good for the age. I've already checked, tested and cleaned all relays pertaining to the fuel and PCM systems.

I really doubt its the fuel pump, I am almost certain its the fuel pressure regulator. I will get fuel pressure readings tomorrow when I get a chance.

Also, there is no shuttering, sputtering, or misses when she does fire up. Runs very smooth just like nothing happen.
Another thing, I am not getting any codes or weird readings from the MAF, IAT, TPS, and IAC durring the problem and not during the problem. Thats about all my reader will read.

 

[lorenambrose]

Crankshaft position sensor controls the ignition timing and spark. Camshaft position sensor controls the fuel timing and delivery. Without an input from either the engine will not start. You are going to spend a fortune like I did only to fix the problem with one of these two sensors. I would change both and solve your problem. Cam sensors corrode very easy, and crank sensors get weak magnets from vibration. these censors can be had for about 25 bucks each.

And yes these sensors are notorious for being intermittent so sometimes it starts and other times it will not, but when it does it runs great.

 

[frickea86]

I never even thought of looking at the Crankshaft or Camshaft position sensors. I will probably replace these as well. I'm saving up to just do a small over haul on the sensors. Before I do anything, I am getting a fuel pressure reading tonight.

 

[lorenambrose]

any news on your problem?

 

[outdoorman99]

did you ever fix this? i need the answer so i can fix mine!

 

[frickea86]

Actually yes, after checking the fuel pressure and finding out that it was not at the correct PSI we soon tracked down why that was. It was very random and it only happen on damp days. I pulled all fuses and relays again for the fuel system and throughly cleaned all connections as some I did fine to be corroded. Put everything back together and have not had a problem since.