Having to crank twice when cold

[natenkiki2004]

My Explorer requires cranking twice for the first time of the day (when cold). Never happens when it's hot or if it's been sitting a few hours (still a bit warm).

Here's a video of what I'm talking about:
https://www.youtube.com/watch?v=5LLOIC2KniY

It catches but when I let go of the key, it dies. You can see the tach jump when the engine tries to start. Engine always fires off on the second go.

What I've done and some info;
- Replaced and twice tested the IAT (intake air temperature sensor) and ECT (engine coolant temperature sensor). The IAT fixed the issue for a while but now it's back even though the IAT tests within spec hot and cold.
- Did a fuel pressure test but with a loaned gauge in a parking lot. I didn't get extended information or bleed-off info. What I did get was 35PSI with the key on engine off, 30PSI while the engine is running, and then dropping to about 17PSI a few minutes after shut off. There wasn't any change with revving the engine which I thought was kind of odd. The fuel pressure regulator doesn't have any fuel coming out of the vacuum line but still could be faulty. I plan to do injectors some time and will install a new regulator on then. I know the fuel pump was replaced by the previous owner but there's been quite a few miles put on it since. Maybe the check valve is starting to go?
- Cleaned and ohm-tested IAC (idle air control). This still could be faulty as far as not sealing properly or??? This is the factory unit with 225K miles on it.
- Cleaned the MAF by soaking overnight in vinegar. I should get some MAF spray next time I'm at the auto parts store.
- It's got a new air filter, plugs, wires, coil tested both primary and secondary.
- Vacuum seems on the low side (~17.5-18 in hg) and smooth when idling, but it may just be deeper gaskets. Vacuum boots are recently replaced but starting to crack, no leaks though. Trans modulator isn't a culprit as I'm not consuming trans fluid and the vacuum remained unchanged when unplugging the trans line. I will be swapping over all the vacuum lines to silicone hose without boots.


This is more annoying than a critical problem but I'm growing more and more concerned for my starter as my battery cables are needing replacement and I'm trying to be easy on it in the mean time.


Any ideas? Thanks.

 

[Anime]

Hard to say for sure exactly what it is, but it could be a more basic cause.

First thing is, when you start it, do you turn the key to the "ON" position and wait a few seconds while the fuel pump whirrs and turns on, then only turn it to the "START" position after the fuel pump is quiet again, or do you just turn it to "START" like it's a newer vehicle? An Explorer with newer parts can usually deliver enough fuel to deal with being started without allowing time for the fuel pump to prime, but will often fail to start on the first try when operated in such a way. It's much better to start it only after the fuel pump has fully primed and is quiet.

If it's still not starting on the first try even when starting it properly, my first guess when it comes to starting issues is usually electrical, either the battery itself, the starter, or the cables. A battery that is slowly dying can give trouble starting a cold engine after it has sat overnight, but not during the rest of the day, since the alternator has been charging it after the initial start. You might try swapping out the battery for one from another vehicle to check this, or it may be worth just buying a new battery depending how old the current one is.

The starter could also be getting worn out, or it could just not be getting enough juice from the battery on that initial cold start. When I rebuilt the starter with new brushes, starting improved to being near-instant with the turn of the key. This was with a nearly new battery, cables, and fuel pump.

The cables themselves can also limit the current that the battery can deliver to the starter. Old cables sometimes have corrosion that is inside the cables, occupying the space between the copper strands. If you're planning to replace the cables anyway, you can cut the sheathing with a utility knife to inspect the strands and see how bad any corrosion is, then use shink tubing or electrical tape to repair the cut sheath.

A fuel pump that is slowly going out can deliver less fuel pressue for that intial cold start as well. Sometimes a fuel pump that is going will not give a strong startup whir when the key is turned, and will either sound muffled, or continue to whine without going quiet after priming. Both aren't good. Just because a fuel pump was replaced doesn't mean it was replaced with a quality part, or that it was done correctly. Plenty of shops simply "fix" fuel pumps by throwing on a cheap universal pump to the stock assembly. Such pumps may not be capable of delivering the proper amount of fuel for the motor. A weak pump that is forced to operate at it's upper limit will run hot, and not last as long as the correct pump for the application.

There might also be even simpler causes, like a partially clogged fuel filter.

One simple way to check the fuel system is just punching the gas pedal when driving - if the engine will rev up quickly, and the acceleration is smooth with no hesitation or sputtering, that usually indicates fuel delivery is working well. Of course there can be ignition and air delivery issues that affect this rather than fuel, but either way, it still lets you know something is wrong.

 

[natenkiki2004]

Every time I start it (and any other vehicle) I wait for the fuel pump to finish priming and then start. I don't recall if priming twice helps cold starting or not, I'll have to check.

I forgot to say, I replaced the fuel filter a few months ago. I can punch it going down the highway or from a standstill and it goes just fine. Aside from cold starting, it's a peppy engine, at least to me.

It may just be my battery cables. I know the negative is in horrible condition. I broke the clamp and had to get a bolt-on replacement (which the previous owner also had done) and there was plenty of green inside, more corrosion than copper:
https://dl.dropboxusercontent.com/u...ictures/Battery Cable/IMG_20140414_162806.jpg
I wire-brushed it as best I could and put the clamp on. The positive cable looks factory, it's pretty beat up and faded. I didn't have the cash to buy new cables and it looks like they're routed all kinds of fun places so I'm not really looking forward to that job. I'll probably have to do it before winter though.

The battery isn't brand new but delivered plenty enough power during last winter. I think it's 5 years old. I should get it tested just in case.

 

[Roadrunner777]

Sounds familiar...

http://www.explorerforum.com/forums/showthread.php?t=409486

 

[natenkiki2004]

I actually had read your story before posting this and that's what made me think of the check valve. I think the pump is fine but that valve might be on it's way out. I don't think my lines retain pressure for very long. My truck was down a week or longer while I messed with the power steering. When I went to turn the key, I heard the fuel lines/rail burping air out. I don't hear this when I start it day to day but maybe there's just not enough pressure being built up due to the check valve.

I primed twice this morning and got the same result as the video. If it's fuel related then I'm either not building the pressure (pump) or holding pressure (FPR/check valve).

The question is, which should I try to tackle first? Fuel pump or battery cables? Fuel pump is cheaper but I KNOW the battery cables are on their way out.

 

[Anime]

Battery cables are not that expensive, unless you're set on getting brand new Ford/Motorcraft cables.

There's a whole thread on them here:

http://www.explorerforum.com/forums/showthread.php?t=250186

They aren't that tough to replace, though it is a little tricky snaking the old ones out and getting the new ones in, especially dealing with bolt-on brackets and the like. If the split loom tubing is too crispy or corroded to re-use, Lowe's sells the same sizes of split loom, wrap with electrical or cloth tape in the same configuration as the old cables, attach everything and you're done.

I think I still have an OE Ford takeoff negative cable that's in decent shape that I'd sell cheap, depends on the battery position though since they are different on some 91-92's than 93-94's

I'd do battery cables before dropping the tank and replacing a pump, no question.

 

[natenkiki2004]

That actually doesn't seem too bad. I think I'll go that route first. I know the previous owner replaced the fuel pump but it looks like the battery cables are OEM and on the 2nd clamp-on connector on the negative lead. Not to mention, I have oil pan leaks and had a power steering leak for ages so the positive cable could be soaked in that.

Looks like the 2 cables at NAPA are just shy of $100 for both, the better quality lifetime warranty ones, shown in that how-to thread.

On a related note, I know the starter was replaced but the bolt holes were stripped and a regular bolt & nut were used. Last thing I want to do is go about fussing with that thing so I'd like to have as little stress on the starter as possible.

 

[Anime]

The Motorcraft cables from Ford are about the same ~$100. If you're set on the NAPA ones, you could try asking for discounted shop pricing in-store, usually friendly counter guys will give you shop pricing for expensive items since the markup is so steep.

Rockauto has much, much less expensive cables. The Standard motor products ones seem to be the same as the NAPA cables, at least going by the pics.

http://www.rockauto.com/catalog/x,carcode,1119608,parttype,2500,a,Ad+Code+www.google.com+

If you buy from Rockauto, don't forget to use their 5% off coupon, available in the Forum Vendors thread.

 

[Roadrunner777]

I concur, it sounds like you need new cables no matter what.

 

[Roadrunner777]

I spent some time today actually tinkering with the fuel system, and I need to correct myself... trying to catch every place I mentioned this. This problem has nothing to do with the duckbill check valve. The duckbill valve is downstream of the fuel pressure regulator, so it does not come into play here. That leaves three possibilities: The check valve inside the fuel pump body, leaking fuel injectors, or a problem with the fuel pressure regulator. Since replacing the fuel pump assembly fixed my problem, I'm going with that. In your case, I'm still for replacing the battery cables if they are questionable... you should do that anyway.

 

[natenkiki2004]

Leaking fuel injectors was brought to my attention again. It actually sounds like a pretty reasonable cause since when I crank it the first time, it DOES catch which could mean it's firing off of residue fuel in the cylinders and then dying since the fuel system is drained.

What gets me though is even if I prime it twice, it still behaves the same. Maybe I need to prime it more to get all the air out?

Both the battery cables and injectors (and possibly the fuel pressure regulator) are all factory original and I'll end up replacing them all eventually.

I just bought battery cables today, should be able to pick them up tomorrow. Not sure when I'll get to replacing them but it should be in the near future. I know they need to be done so it's my first step. I'm pretty sure my fuel pump is good since it builds pretty good pressure and I don't have poor acceleration. If the cables don't help, I'm going to wait and see if new injectors and fuel pressure regulator fix the issue. If not then I'll be back for more opinions.

 

[natenkiki2004]

Well, I got new battery cables. The old ones were absolutely horrible. They had turned black from heat and corrosion. Several connections were suspicious. Unfortunately, it didn't do anything for my starting. In fact, after taking half a day to install the cables, I had to crank it twice to start it for a test drive. On the plus side, my voltage appears to be higher.

I think my next purchase will be a set of remanufactured injectors and fuel pressure regulator. I don't mind throwing money at them since I should at LEAST see a MPG improvement since they are the factory injectors with 226,000 miles on them.

Possibly unrelated but I pulled my MAF and saw visible crud on it even though I had soaked and cleaned it in vinegar about 1,500 miles ago. Sprayed it down with proper MAF cleaner and it looks good.

 

[Wolfie_85]

I'm with the crowd that says it's a fuel issue. A few basic things are your fuel filter, or maybe fuel pump relay. Leaky injectors could also be it. Without knowing exactly what component is causing the issue, I always replace the cheaper, easier stuff first. On an older vehicle, it never hurts to do this anyway. Could be electrical, too. But it doesn't sound like it to me.

 

[natenkiki2004]

It definitely is a fuel issue. I let the Ex sit for 3 days and went to start it (I always wait for the pump to prime) it had a pretty good burp so I primed it several more times (8 to be exact) and it ALMOST started normally after plenty of burps.

The fuel rail is draining out. It's gotta be a leaky injector, bad pressure regulator or the check valve in the pump. I've already replaced the fuel filter, not that it would cause this issue.

I'm going to spring for rebuilt injectors and pressure regulator. I know there's room for improvement at 14MPG on old-style injectors with 226,000 miles on them. I certainly won't go backwards on that deal. If it fixes my issue, great. If not, I'll go for the pump assembly. I'm no longer worried about the pump after reading about the whole cutting a hole in the floor thing.

 

[smegun]

i was a messing with a lot of things and disturbed the fuel regulator connection .....i had the two times to start problem until i replace that vac line end that attaches to the fuel regulator and small plastic vac line if you look at it it has a gromet for an inch on the plastic line and it adapts to the normal size with an inch on the bigger regulator bib a dorman mix pac on the shelf had a few different pieces that adapt to the two different type tube bibs 1 of them is the right fit they say there not the best quality but you just cant keep sliding them off and on after 10 years too bad they dont give you the 90 degree ones to boot 6 bucks for a pinch of silicone is on top of the coffee and cigs

i am searching for my next vac problem i can here the system hissing as it fills during start up although it sounds like its comming from my rear door but i could be hearing things maybe this is normal but i want to check the vac to the tranny and any other areas that might be causing vac problems including power braking


are there any surprise connection rubbers that need checking ?

 

[natenkiki2004]

I replaced all my vacuum line with silicone hose, I got tired of the boots failing and finding new holes in the plastic factory lines. The silicone is much thicker, adapts to the different fitting sizes easily and the blue looks pretty cool in the engine bay. Take a look at my signature.

 

[2stroke]

One thing you could try if you replace the fuel filter, is to replace the quick disconnects.