Just bought truck - 4.6L won't start...

[Mircury]

Hi guys,
I'm the proud new owner of an '02 EB V8 with 170,000KM (106k miles) and new to the forums, here. I purchased the truck cheap because it was not running. The previous owner said the truck seemed to lose power while driving. They pulled over, towed the truck to a shady mechanic. He worked on the truck for three months, unsuccessfully. The engine did start for me ONCE. It had what sounded like a bad vacuum leak, as it was hissing, while trying to idle. I shut it off after only running for 10-15 seconds. It hasn't started since, though it tries... it seems to sputter a little, here and there.

I'm looking for some suggestions as to where to start. The truck has new cats. I plan on first draining the 1/4 tank of fuel while changing the fuel filter. So far, I have tried to start the truck with each of the following sensors disconnected (one at a time), to see if the computer would use 'default values': MAF, TPS, IAC... no go :thumbdwn:

What do you guys suggest? I am very mechanically inclined and have done motor/tranny swaps and other major repairs in the past.

Sorry for the massive post but where do I start?

 

[swetrid]

Ck fuel pressure manually, fuel pumps are very common on these. They also can blow the fuel pump fuse under the hood in the fuse panel.

 

[Mircury]

Ck fuel pressure manually, fuel pumps are very common on these. They also can blow the fuel pump fuse under the hood in the fuse panel.

Fuel pressure is present at the fuel rail, though I haven't tested pressure. How and where do I check fuel pressure?

 

[zerodevil]

there is a gauge you plug into the fuel rail, easily found, but its a little spendy for garage use. the hissing bothers me, could be a cracked block or SERIOUSLY blown head gasket.

 

[Mircury]

I'm unfamiliar with this coil-on-plug stuff.. will I be able to get my standard compression gauge in there? Is it regular plugs beneath the coil?

 

[Erik88]

Yes, if you remove the coils(unplug and 1 7mm bolt per coil) you will reveal the plugs a few inches down. Make sure you slightly loosen the spark plugs(do not take them out) and blow high-pressure air in the spark plug holes to clean the holes out. They LOVE to collect dirt, water, anything that can get down in the holes. Once they are clean you can remove the plugs and do a compression test as normal.

 

[jakedrew]

I would see if it has spark.

that fuel pressure guage I think you can rent from autozone/ parts store for free. Is there a schreader vavle on these explorers? Cant say I LOOKED that close at mine.

My brother has a focus and the coil pack went out and it made some crazy noises like you describe.

Start simple.

keep us updated.

 

[Mircury]

Yes, my engine has a schrader valve on the drivers side rail.

I am going to do the following this week:
-Check for spark at each cyl
-Check for injector pulse at each cyl
-Check compression at each cyl
-Check fuel pressure at fuel rail
-Drain tank and add 1/4 tank of premium fuel
-Change fuel filter

Does anyone have anything to add or note?

 

[Mircury]

I noticed that the engine oil has been overfilled. It's sitting about an inch above the 'full' marking on the dipstick. Could this high oil level be contributing? Are there any sensors that might be sensitive to overfilled oil in the crankcase?

 

[matt0248]

I noticed that the engine oil has been overfilled. It's sitting about an inch above the 'full' marking on the dipstick. Could this high oil level be contributing? Are there any sensors that might be sensitive to overfilled oil in the crankcase?

It is possible that because the engine was sitting for a very long time that all the lifters and such have drained down. I would let it be until the engine srarts and runs then recheck the level.

As far as the to-do list. The list is a great starting point to check what is going on.

 

[Mircury]

Update:
So I had some time today to check injector pulse. All eight injectors showed a negative pulse. I then pulled out a plug and went around coil to coil with the grounded plug. All coils fired. Plugs looked like new, Bosch Platinum plugs - not my choice. Engine was trying to start while I was doing spark test. It actually started on 6 cylinders and had to yell for my gf to kill it. I finished my spark coil tests and put everything back together minus the intake air tube. I unhooked the MAF. Boom, started right up, started idling with just a VERY slight miss, every so often. Pressing the accelerator only raised RPMs to about 1200 but wouldn't climb higher... then it stalled out, from what I assume to be a rich/lean condition. Truck started one more time then nothing afterward. Back to square one. The truck tries to start, firing well, but not enough to keep running. Then the firing goes away and it's just being cranked over. Then it comes back, a few seconds of cranking later... The hissing was not present today. when it ran.

Fuel pressure testers weren't available to rent, only for purchase at $60. I figured I would wait, as I might find fault in some other component, before I blow $60.

Tomorrow I'm going to pick up 8 Motorcraft plugs from the dealer and change out the Bosch Platinums while doing a compression test. The coiled wire attached to the coil was dry, no grease. Wouldn't it be a good idea to apply dielectric to all these coils?

 

[sethmorgan]

Lean condition could be caused by a vacuum leak. Have you had the codes read to see if the O2 sensors are complaining?

 

[Mircury]

The truck had no battery when I got it, effectively clearing any codes. I haven't had it running long enough to trip the light... I'm putting in Motorcraft platinum plugs tomorrow and post results tomorrow.

 

[sethmorgan]

The truck had no battery when I got it, effectively clearing any codes. I haven't had it running long enough to trip the light... I'm putting in Motorcraft platinum plugs tomorrow and post results tomorrow.

It may still have codes stored. Certain criteria has to be met in order to illuminate the CEL. But the codes might be there now.

 

[Mircury]

Checking codes revealed only one:
P0113 : Intake Air Temperature circuit high input

Fuel pressure gauge at rail:
35psi

Motorcraft plugs and compression test tomorrow...

 

[Mircury]

Okay, I installed the new Motorcraft spark plugs, put dielectric in the coil boots. I was unable to perform a compression test as my tester wouldn't thread into the heads. The engine now doesn't even sputter, just turns over.

How do you check timing on this engine? Is it possible that the timing chain jumped a tooth or something?

HELP! :S

 

[Mircury]

Update:

-Check for spark at each cyl - Good spark on all cyl
-Check for injector pulse at each cyl - negative pulse present at all cyl
-Check compression at each cyl - not yet done
-Check fuel pressure at fuel rail - 55 PSI
-Drain tank and add 1/4 tank of premium fuel - Done, No change
-Change fuel filter - Not yet done

I have found a 4.6L motor, same year (2002) from a Mustang - will it be a straight swap and work with all the Explorer connections?

 

[matt0248]

Explorer has an aluminum block, mustang has a cast iron block. Other than that is should be the same. (i think)

EDIT. It sounds like it is time to take the vlave covers off and inspect the timing chains. I think you can peek down with the valve covers off.

 

[Mircury]

Explorer has an aluminum block, mustang has a cast iron block. Other than that is should be the same. (i think)

EDIT. It sounds like it is time to take the vlave covers off and inspect the timing chains. I think you can peek down with the valve covers off.

I have heard that the Mustang and Explorer engines are the same, minus block material, mounts and the Stang has +21HP.

Has anyone done this swap? Where do the 21 ponies come from? Would my truck see the increased HP, or would it be dialed back down by the PCM?

What am I looking for with the valve covers off?

-Thanks!

 

[sethmorgan]

Is it possible that the ignition timing is off? Not sure with the coil-on-plug, but it's an easy thing to do with the V-6s and the coil pack.