Fordguy15
New Member
- Joined
- September 7, 2011
- Messages
- 2
- Reaction score
- 0
- City, State
- Augusta, Georgia
- Year, Model & Trim Level
- 2003 Explorer 4.0L
I have a 2003 Explorer with the 4.0 V6 vin K for flex fuel. I have had this skipping problem since I purchased the truck earlier this year. Seeing as I am a technician with a good bit of experience, I thought I would be able to fix the skip. Unfortunately I was not able to drive the vehicle more than a foot from where it was parked before I bought it so I was unaware of the serious problems.
After purchasing the truck, the trans went out in it, and I had it completely rebuilt with a warranty. But the skipping was still an issue. Here is what is going on.
As soon as you start the engine, there is a misfire prominently in cylinder 5 and occasional in 6, but if left at idle for a minute or more there is a random/multiple cylinder misfire. The skipping remains noticeable at low rpm even when driving, such as cruising on the highway. It seems to go away any higher than 22-2300 rpm. When it has a multiple/random misfire to it, the CEL flashes for a little bit until it is driven/rev'd up then it will stop flashing. Also when it is running bad enough that the light flashes and you start going, you can notice a power increase as soon as it "stops skipping".
With all that said, I have tried to use my diagnostic skills to cure it, but have had no luck. Here is what I have replaced after have been led to think of the source.
Spark plugs (E3 plugs)... btw great plugs!
Spark plug wires
Coil pack
Fuel Filter
Idle air control valve
O2 sensors (upstream)--- Had a code for too lean AND too rich on both banks, so far code has not come back since replacement
Fuel Injectors
Intake manifold gaskets
Camshaft position sensor
Crankshaft position sensor
I have also done a leak down test, compression test, and fuel pressure test and all of them were in great ranges from factory specs! Now there is another thing, after another problem of the starter going out and having to replace it, I noticed a tag on the bottom of the engine that machine shops use after rebuilding an engine, so the engine apparently was rebuilt.
On TOP of all of these parts replaced, I performed a fuel injection cleaning (prior to the new injectors), scrubbed the throttle body, and cleaned the MAF with MAF spray until it was as clean as a whistle!
I dont know what else to do!!! HELP ME PLEASE!
On a side question, if the engine was rebuilt, or lets say they put a rebuilt engine in it, could they have put in the regular gas engine and the ecu is not computing right cause its the flex fuel ecu causing a messed up stoichiometric ratio?? Not saying thats what happened, but is it possible?
After purchasing the truck, the trans went out in it, and I had it completely rebuilt with a warranty. But the skipping was still an issue. Here is what is going on.
As soon as you start the engine, there is a misfire prominently in cylinder 5 and occasional in 6, but if left at idle for a minute or more there is a random/multiple cylinder misfire. The skipping remains noticeable at low rpm even when driving, such as cruising on the highway. It seems to go away any higher than 22-2300 rpm. When it has a multiple/random misfire to it, the CEL flashes for a little bit until it is driven/rev'd up then it will stop flashing. Also when it is running bad enough that the light flashes and you start going, you can notice a power increase as soon as it "stops skipping".
With all that said, I have tried to use my diagnostic skills to cure it, but have had no luck. Here is what I have replaced after have been led to think of the source.
Spark plugs (E3 plugs)... btw great plugs!
Spark plug wires
Coil pack
Fuel Filter
Idle air control valve
O2 sensors (upstream)--- Had a code for too lean AND too rich on both banks, so far code has not come back since replacement
Fuel Injectors
Intake manifold gaskets
Camshaft position sensor
Crankshaft position sensor
I have also done a leak down test, compression test, and fuel pressure test and all of them were in great ranges from factory specs! Now there is another thing, after another problem of the starter going out and having to replace it, I noticed a tag on the bottom of the engine that machine shops use after rebuilding an engine, so the engine apparently was rebuilt.
On TOP of all of these parts replaced, I performed a fuel injection cleaning (prior to the new injectors), scrubbed the throttle body, and cleaned the MAF with MAF spray until it was as clean as a whistle!
I dont know what else to do!!! HELP ME PLEASE!
On a side question, if the engine was rebuilt, or lets say they put a rebuilt engine in it, could they have put in the regular gas engine and the ecu is not computing right cause its the flex fuel ecu causing a messed up stoichiometric ratio?? Not saying thats what happened, but is it possible?
