Help Wont start, starts intermittently

[jpurdie]

Hi
This is my first post on ExplorerForum. I have a '93 Explorer Eddie Bauer with 150k miles. 4.0L, automatic

A few weeks ago it started acting up.
The Explorer will start up just fine and drives like normal, after I stop the engine ether after a short trip or long trip when I go to restart it the engine cranks over just fine but it won’t start, it acts like it wants to start but it won’t, after I wait anywhere from 15 min to an hour it will start up just fine and drives normal until I shut it off again.
I can go on long trips 100+ miles and it runs just fine as long as I don’t shut it off.

I have read 1000’s of post on this site and others but can’t figure it out.
I have taken it to 2 shops and both shops could not get it to repeat the no start condition, 1 shop even had the Explorer 3 days and could not get the problem to repeat. He even put 20miles on the car so I know he was trying.
Both shops said NO bad codes have come up. I don’t have a code reader so I’m only going by what they said.

Here is what I have done so far in the last 2 weeks to try and fix the problem.
Replaced the fuel filter (Fram filter)
Replaced the complete fuel pump assembly (Motorcraft part) Thanks to this site for the info on cutting an access hole in the body.
Replaced both the fuel pump and EEC relays with new relays (ACDelco part)
Replaced both battery cables, positive and ground
Replaced Crankshaft Position Sensor (Motorcraft part)
I cleaned the Mass Air Flow unit
I had the plugs and wires replace about 4 month ago prior to having this problem (Motorcraft wires, BOSCH plugs)

I have tested with fuel pressure gauge when I get the no start condition and I get 32psi at the rails
When the cars running I get 30psi, and 37psi when I disconnect the vacuum line from the fuel pressure regulator.
Never seen any fuel leaking from the vacuum line from the fuel pressure regulator when I have disconnected it.

If I spray starting fluid in it, it starts but dies right away, that’s what makes me thinks it’s a fuel problem.
I have not test to see if it’s getting spark at the plugs in no start condition, but will try today.
I have not tried testing the fuel injectors (not sure how to do that)

I have tried disconnecting a few of the sensors when I get the no start condition and still it won’t start except one time I disconnected the Air Charge Temperature Sensor and it started but when I tried it again it would not start.

No check engine light comes on while it’s running unless I disconnect a sensor like the Air Charge Temperature Sensor, than I will get a light in the dash but goes out as soon as I plug the Sensor back in.

One of my mechanic said he thought it might be the Ignition Coil.

I’m really just thinking about replacing a bunch of the sensors and even the Engine Control Module (Computer)
My next step is trying a new Ignition Coil and or the Ignition Control Module and see what happens.

Any thoughts or ideas would be great
I just love my Explorer and don’t mind spending the time and money it will take to get it going, I just put a new transmission into it 6 months ago and a $500 sound system in it a month ago, I hate to give up on it.

 

[Dano!]

i dont know if it would help, but you seem desperate. when i was troubleshooting my fuel problems, it would start and run and quit, i replaced everything like you did, and what it ended up being for me was a faulty ground from the sending unit.
its a stretch but if you wanted to test it, just splice your ground comming out of the sending unit (you said you replaced the whole thing so im assuming its good) and ground the wire somewhere else on the frame. (like where your fuel recepticle grounds too)

i would hold out though until some of the more salty guys put their two cents into this. no need cutting wires if someone else can point you in a better direction.

 

[Tony H]

Although it sounds heat related.. Does Anyone have a feeling it might be that Collision switch on the passneger side giving him a problem??

 

[MrShorty]

I have not tried testing the fuel injectors (not sure how to do that)

Low budget: injectors make an audible click when they fire. Can you hear the injectors?

Next part of diagnosing the injectors would be to verify that they have power.

The PCM is responsible for "firing" the injectors, make sure the PCM has power/ground.

 

[jpurdie]

I was able to read the codes thanks to MrShorty's post on pulling EEC-IV codes

Here are the codes
116
(O,R)
Engine Coolant (ECT) sensor out of range - ECT
114
(O,R)
IAT sensor out of range – IAT


113
(O,M)
IAT sensor is/was high or open - IAT
211
(M)
Ignition PIP signal was erratic or missing - Ignition Systems
212
(M)
Ignition TACH signal was erratic (module/wiring) or SPOUT circuit fault - Ignition Systems
543
(O)
Fuel pump monitor circuit shows no power - Power / Fuel Pump Circuits
556
(O,M)
Fuel pump relay primary circuit fault - Power / Fuel Pump Circuits

I guess my mechanic never seen or read the codes??? Any ways I know can replace the ECT and IAT sensors easy enough but I think the problem is with codes 543 and 556

I also pulled the Fuel Pump Inertia Switch off earlier to take a look at it before I pulled the codes, seems to be working as it should?
Not sure how to test it. If I shake it you can hear the ball and the button pops up.

Thanks for everyone’s help on this, any ideas on where I should go next would be great

 

[Iron Weasel]

You can get 114 & 116 if you (or anyone for that matter) runs the ECM through the self test without the engine being at operating temperature. Also, you'll get 543 & 556 if you have the key on at anytime with the inertia switch disconnected or "tripped".

If you can find a cheap ECM in a junkyard, I would suggest giving that a shot.

 

[MrShorty]

Not sure where I'd start.

1st, you listed the codes in numerical order. I'd probably suggest you start by distinguishing the KOEO codes from the CM codes. SOP is to resolve the KOEo codes first. In doing so, I'd probably ignore the KOEO 114/116 because those are likely related to the no start and will be better resolved after getting it started.

Which would leave us with the KOEO 543/556 which points to something in the fuel pump circuit (unless these were triggered by having the inertial switch removed). If these end up being triggered by your removal of the inertia switch, then we are at the point of trying to determine what is going on with the PIP/TACH signal from the CKP.

 

[92exp4x4]

If these end up being triggered by your removal of the inertia switch, then we are at the point of trying to determine what is going on with the PIP/TACH signal from the CKP.

Alphabet soup anyone?

P.S I know what these are, this sentance just struck me as funny

The PCM (powertrain control module) controls the ground to the fuel pump relay which activates the fuel pump. It is very possible for there to be a problem within this circut or the PCM itself.

With your truck being a 93 it may or may not have California emissions. If you replace the PCM for any reason, make sure you are getting a 93 PCM without EGR (assuming yours does NOT have calif emmisions controls) and for an auto trans. California trucks had EGR, and a Cam Positioning Sensor. These are at least the basic tell-tale differences, earlier models did not have this and all 94s did.

Good luck