03 Sport Trac Fuel Injector Dead????

[dbailey]

Ok, so I had a new 4.0 long block installed after a valve spring broke at 265,000 miles. Now there is a misfire in #5 cylinder (P0305 and P0316 codes). Only kicks code after having sat for awhile. Checked the plug in #5 and it is wet with gas. After I start it and let it idle for a minute or two then rev it a few times it clears up and runs fine. Happens every time I drive it then let it sit. Before I go throwing fuel injectors at it, just wanted to bounce it off of the site to see if there is anything else that would allow gas to wet the plug after you turn it off and it sits for awhile. Any suggestions/ideas? Thanks guys for your help.

 

[TestPoint]

Sounds like a leaking injector to me.

 

[arco777]

That is an odd one... barring a wiring issue it does sound like a faulty injector that is not seating closed. Considering the typical longevity of a fuel injector, I would suggest replacing only that one. A junkard injector with low mileage should be sufficient. Injector failures are quite rare.

 

[TestPoint]

At 265k miles maybe there is some forgiveness for a failed injector. A professionally cleaned and tested for flow and balance set of injectors can be found for well under a $100. Considering the effort to change one I would change all.

 

[2000StreetRod]

check wiring first

P0316: the PCM has detected a misfire shortly after startup, specifically within the first 1,000 revolutions.

The plug could be wet with fuel because it is not firing. I suggest eliminating electrical problems before replacing the injector:

Check the plug wire electrical connections and resistance
Replace or move the plug to see if the misfire moves

For the injector you might try adding a bottle of Techron fuel injector cleaner to half a tank of fuel. If the injector is leaking it might stop after a few hundred miles of driving.

 

[dbailey]

P0316: the PCM has detected a misfire shortly after startup, specifically within the first 1,000 revolutions.

The plug could be wet with fuel because it is not firing. I suggest eliminating electrical problems before replacing the injector:

Check the plug wire electrical connections and resistance
Replace or move the plug to see if the misfire moves

For the injector you might try adding a bottle of Techron fuel injector cleaner to half a tank of fuel. If the injector is leaking it might stop after a few hundred miles of driving.

Having the dense white smoke at startup I'm thinking it may be coolant getting into #5 . I didn't smell the end of the plug for gas but assumed that to be the case. Will pull it and make sure its gas. If no smell then I am gonna assume it coolant? Gonna be replacing the longblock that is new and appears to have a blown head gasket. Have run 2 bottles of Sea Foam thru it and it is still misfiring at #5 .

 

[2000StreetRod]

eating coolant

I forgot that you had another thread about your vehicle eating coolant. I suspect that you have a cracked head or a blown head gasket that is leaking coolant and fouling #5 plug. I assume that the remanufactured long block you purchased from AutoZone had the head checked for cracks. If so, then the head cracked or the gasket blew out when your engine overheated in the mountains. You may encounter fault finger pointing between AutoZone and the mechanic who installed the engine. I wish you luck.

 

[dbailey]

I forgot that you had another thread about your vehicle eating coolant. I suspect that you have a cracked head or a blown head gasket that is leaking coolant and fouling #5 plug. I assume that the remanufactured long block you purchased from AutoZone had the head checked for cracks. If so, then the head cracked or the gasket blew out when your engine overheated in the mountains. You may encounter fault finger pointing between AutoZone and the mechanic who installed the engine. I wish you luck.

Yeah that's sorta what I was thinking. Guess its between the mechanic and AZ. he uses them ALOT and hopefully the relationship with them will help. Thanks.

 

[dbailey]

I forgot that you had another thread about your vehicle eating coolant. I suspect that you have a cracked head or a blown head gasket that is leaking coolant and fouling [URL=http://www.explorerforum.com/forums/usertag.php?do=list&action=hash&hash=5]#5 [/URL] plug. I assume that the remanufactured long block you purchased from AutoZone had the head checked for cracks. If so, then the head cracked or the gasket blew out when your engine overheated in the mountains. You may encounter fault finger pointing between AutoZone and the mechanic who installed the engine. I wish you luck.

Engine was actually misfiring before the drive. The first attempt to chase it was a replaced o2 sensor on drivers side where #5 is. That seemed to correct the misfires for a day or two then it came back. When that happened he suggested I put a can of Seafoam in it to see if it was a clogged injector before he looked further. That's when it was driven over the mtn. That was first indication of any overheating. That didn't work and it was suggested to try 1 more can in case it was REALLY clogged. That didn't work and here we are. So I'm thinking it was messed up out of the chute. The misfire was there BEFORE the drive. The drive and the time since has just confirmed that fact I'm thinking. Going back to him Tuesday and we'll see how his business relationship with AZ is.