Starting problem

[johnwartjr]

96 Explorer limited, bone stock
Around 150k on the odometer, been in the family since new.

Has a starting problem.

It starts just fine every time if it's been sitting for more than about 40 minutes.

So, it starts fine in the morning, starts fine when my wife leaves work.

But, it acts funny if you try to start the engine within 40 minutes or so of shutting it off.

She has to time her stops carefully, because if she stops the truck somewhere, she knows she has to be there for at least 40 minutes.

When you try to start it, it may start, and then die immediately. Almost sounds like it's choking for fuel. Symptoms remind me of vapor locking. But, it happens regardless of the temperature.

So far, I replaced the fuel pump relay, because I read a few places it could be that. Didn't help.

I have a new motorcraft fuel filter and the tools to change it, just need to find somewhere to change it as I don't have anywhere at home I can lift cars off the ground.

I've read it could be the fuel pump, too. I don't have a fuel pressure gauge, but I don't understand how it could be the fuel pump or the filter, and it works when it's been sitting for 40 minutes or more, but not immediately.

Am I working the right direction with my troubleshooting, or is there something else I should be looking at?

Another odd hint that I should throw out, as I've had to sit in this thing in a few parking lots before, waiting. Right before it will start, I hear a clunk noise from the drivers side of the truck, in front of the firewall.

Also, if I go for a very short drive in the morning, say 5 miles or less, where the truck doesn't get up to operating temperature, I can run in a store, come out, and it will start.

 

[joe doe]

could be fuel pump .starts fine when vehicle is cold,drive it long enough for the pump to get hot then (starting issue).

let it sit long enough for pump to cool ,start right up .

see where i`m going here?

couple things you can try .

take a can of starting fluid with you .when it gets hot enough to give you a no start go hit it with the fluid ,if it runs on the fluid then you know you got a fuel delivery issue .

another thing to try .(this requires a gas can in the vehicle with fresh cool gas)drive it until its hot enough for a no start .when you get the no start go throw the fresh gas in the tank .if it starts up then the cool fresh gas has cooled the pump enough for it to start working correctly .

my explorer has issues with high temp days ,like 95 and up ,on those days my pump overheats and i get stuck if i dont go put some fresh gas in it .i been driving it like this a year or so now .only acts up on real hot days .

good luck

 

[bobflood]

Fuel pump overheating is certainly a possibility. Is the wait interval shorter now that it is winter (colder outside) than it was in the summer?? I like Joe's suggestion for dumping in cold gas when it happens and seeing if that lets it start.

Another thought: Check the temperature sensor the PCM uses (not the one for the temp guage). If it's bad, the PCM might not know the engine is warm and thus be setting fuel, spark, etc for a cold start when it shouldn't.

 

[Millertime1987]

It sounds like it could also be the Fuel Pressure Regulator. Since yours is a 96 it should be in the engine. To test it you would also need to test with a fuel pressure tester.

 

[Stick4503]

I have the exact same problem with my 96 4.0. Just posted it last night. Not sure as to the 40 minutes, mine can sit longer and still have this. If I find anything I will let you know. Please do the same for me. Search my post stick4503.

For those who have made sugestions I am looking at maybe a crank possition sensor as a cause. I have no fault codes. Engine runs a little on the rough side when it cranks but only notice it if you are look at or have your hand on the engine while it's running. Driving after finaly getting it started it seems to have full power.

 

[yavapaires]

It sounds like it could also be the Fuel Pressure Regulator. Since yours is a 96 it should be in the engine. To test it you would also need to test with a fuel pressure tester.

What about a sticking EGR valve?

 

[johnwartjr]

I do have a CEL with an EGR code. I replaced the EGR pressure sensor a few months ago because it was the likely code of the CEL, but the CEL came back after it was cleared. P0401 or P0402 IIRC.

Is it possibly related?

 

[Stick4503]

Did you find out what the problem was.with yours? I have the same thing and cant find the problem yet.

 

[dschmitz86]

stupid thing wont start!

I am in serious need of help. I have basically no car knowledge, i know where the gas goes and how to change a tire (im a girl, cut me some slack). I have a 95 ford explorer xlt, about 140,000 miles on it. My problem started about 3 weeks ago, the truck will run fine but if i start/stop more than twice a day, it wont turn over. Doesnt matter the temp. outside. The first couple times it did this it would take a couple tries to start, sounded like a low battery. Then it got to the point the last week where we had to hook a charger up to it, then it would start. And finally today now it wont start at all. When i turn the key i can hear a short 'hum' sound which i believe is the fuel pump....or something to do with it? I really have no clue. When it wont start, i'll turn the key (all lights, radio, temp display light up) i hear the fuel pump noise (or so i think) for like a second and right after that just a 'tunk' sound...and nothing else. Ive had the charger on it now for like 8 hrs, still nothing. Im broke, its my only vehicle, and im praying its something cheap and easy. Someone please help, im seriously begging!

 

[joe doe]

if you been charging the battery for 8 hours and the starter still wont turn the motor then i suspect you need a new starter .

try getting a jump ,if jumping the battery doesnt make the starter turn then you need a new starter .when a starter goes bad it can run your battery down too if the starter is grounding out internally.

do you have someone who can check the battery connections for you?

also try cleaning the battery connections at the battery and at the starter .
a badly corroded battery wire can do similar things as well.
good luck young lady.

 

[johnwartjr]

Back to this problem again.

Replaced the EGR DPFE and solenoid, and cleared the code today. Hopefully it won't come back.

Now I am seeing a couple new codes

P0133 Oxygen Sensor Circuit Slow Response Bank 1 Sensor 1

The parts counter guy says I have a bad oxygen sensor, but apparently this truck has more than 1. How do I determine which I should look at?

Also getting

P0420 Catalyst System Efficiency Below Threshold Bank 1

They both mention bank 1.

 

[bobflood]

Back to this problem again.

Replaced the EGR DPFE and solenoid, and cleared the code today. Hopefully it won't come back.

Now I am seeing a couple new codes

P0133 Oxygen Sensor Circuit Slow Response Bank 1 Sensor 1

The parts counter guy says I have a bad oxygen sensor, but apparently this truck has more than 1. How do I determine which I should look at?

Also getting

P0420 Catalyst System Efficiency Below Threshold Bank 1

They both mention bank 1.

Bank 1 is the passenger side of the engine; Sensor 1 is the sensor before the catylitic converter.

 

[johnwartjr]

Took it into the shop today to have the fuel filter and rear brake pads changed.

Truck wouldn't start after the new filter was installed, so the mechanic hooked up a fuel pressure gauge and says it is putting out around 30 psi.

He says we need a new fuel pump. He got one, started to drop the tank, and the strap holding the tank in broke, so he ordered new straps.

Hopefully, tomorow, he can replace the fuel pump, and it'll solve the problem.

 

[johnwartjr]

Got the truck home. New fuel pump fixed the problem. Wife will be happy that she can now drive around as much as she likes, without having to wait an hour to restart

Same mechanic is changing the motor mounts in my Supercoupe today. I really wanted to do that job myself, but I'm too busy with work to consider it right now.

So, consider this one 'fixed' and the fuel pump the culprit! Wish it were a cheaper choice