'99 Explorer Difficult to start off and on

[goahunter]

Hi Im new to this forums and this may be answered somewhere else, but thanks for any help you may have. I own a '99 Explorer with V6 4.0L SOHC. It has 138k miles and within the past 10-15k miles has become harder and harder to start. Sometimes the car will turn over very easily then other times it will take 30-45 seconds to start, and it seems at random when it happens. I have replaced the spark plugs, the wireset, cleaned the air intake, cleaned the injectors, replaced the air filter, and cleaned the IAC. Any ideas of what could be wrong or how to fix it?

Thanks!

 

[ZBlackBeast]

How about your fuel filter and fuel delivery?

 

[goahunter]

am going to change the fuel filter next, hopefully ill have time today to go to autozone and get a new one. I hear the fuel pump kick on when i first insert key, but is there any way to test and see if there isn't a vacuum leak or if the pump is faulty? I don't have much experience with fuel pumps.

 

[ZBlackBeast]

I forget where it is but there is a way to test the pressure somewhere in the engine bay... If you had a vacume leak it would still start, but die off slowly and or have a choppy idle.

 

[outdoorman99]

did you ever fix this problem? i am having the same one with an identical explorer.

 

[goahunter]

No not yet, I have changed the fuel filter, ignition wires, spark plugs, the Fuel pump whizzes when the key is turned to the run position so i dont think it is a problem there. My last guess that i haven't had time to do yet is to drop the fuel tank and change the fuel filter in the tank. I find that it does the most after sitting for a week so I'm considering the possibility that this might be the problem. If this works or you find a solution let me know. Ill keep you updated.

 

[outdoorman99]

i've been reading about the crankshaft position sensor being dirty/in need of replacement, which allows the car to crank but not to start. I dont have a lot of mechanic experience, but before you rip anything apart i'd search the threads and check it out. I think the people who have fixed it have simply cleaned the sensor, which they say is about a $20 part.

I don't think my problem is the fuel pump because i can clearly hear it before i start the car, and if i give it a ton of gas before starting it it reeks once it gets started. Its been babied (only 75 000 kms on it) and recently had the fuel injector service done (or whatever else they charged me for, saying it would improve my fuel economy...waste of money) so i dont think its a fuel problem. So i dont think its a spark problem. (not that i've tested it, but like i said, everything on it is still practically brand new) I've had the explorer hooked up to 2 different computers with no codes, so i dont think its a computer problem.

Once i get the heater in the garage working i'll try to find it and fiddle with it a bit tommorow. The difficulty with an itermittent problem is that i wont know if that fixes it until it fails again while i'm working up north in -30 celsius. lol.

 

[goahunter]

lol i understand. I also had the injectors cleaned for free by a friend of mine at toyota. They were pretty clean since the car didn't smoke while or after he ran the injector cleaner through the air intake. I did notice that when I changed my fuel filter that there seemed to be quite a bit of debris that drained out. I will check into the crankshaft position sensor too and see if it does anything.

 

[goahunter]

Just wanted to let you know outdoor man that I do believe that cleaning the position sensor did the trick. The pickup was very dirty. After cleaning it I havn't had a single delayed start. I do have to warn you though that this sensor was a ***** to take off and put back on due to its placement. It is highly ideal to have 2 people do this since you cant see anything that you are doing, and be careful that you dont drop any of the screws in such a cramped place. Overall this took me nearly 3 hours to do.

 

[goahunter]

sorry double post