Odd P0171 & P0302

[FordGuy81]

Update

Today I worked the van, but didn't get as much done as I wanted to. I ended up having to tear the the intake of twice. First time, I noticed that someone had already replaced the isolator bolts. I cleaned up the EGR ports, wiped down the intakes, installed new plugs, wires, and coil pack. I also removed the fuel rail and checked out all the injectors. They looked fine, but I swapped #2 injector with #4. I buttoned everything up and went for a drive. Sure enough, I code another misfire code, this time for #4 cylinder.

Faulty Fuel Injector!

Went and bought a new injector and installed it. Van runs better than it ever has. My wife took it for a drive to the store and called to tell me that she needs to get used to the new power, lol.

Anyway thanks everyone for all the help you have provided.

Bill

[LeSabre97mint]

Fordguy

I've very glad that you found the problem to be a bad injector! Way COOL! Now you need to tell your wife to watch out and be careful not to speed. All of that power!


Dan

[FordGuy81]

Thanks LeSabre,

You nailed it being a fuel issue. Even my wife, who doesn't know much about cars, had said 'may its a fuel injector'. Those EGR ports were REALLY cruddy, #6 had a little mound of gunk over the hole. The others were pretty bad. Now I just have to change the oil and flush the tranny.

Never really noticed how much the van lacked until I cleaned up the EGR ports and replaced the failing injector. It still puzzles me that after clearing the misfire code, the van would run like nothing was ever wrong with it. I mean we put ~25K on the van with it like that.

Bill

[12Ounce]

Congrats on your find and repair. Moving the injectors, as well as plugs and wires, around after a misfire code to see if the misfire "moves" is a good technique.

The time to use injector cleaners in the fuel is before there is a misfire! If used during a misfire, and the misfire is not immediately cleared, there is a danger of the cleaner passing on thru the engine to the oxygen sensors and catalytic converter. Not good! Best to use this stuff sparingly and as preventive, not remedial, action. I add a few ounces of clean motor oil to a tank fillup ... when I think to do it. This seems to keep my injectors clear ... but this is my own "experiment" ... I'm not recommending it to others. I've never had to replace any injectors ... but once, on an Escort, I convinced myself I should replace them. So, lets say, I invested some money in education!

BTW, I have about totally eliminated the problem of EGR jet foul-up by glueing the lower horn extentions, six of them, that stick down into the air intake spacer. The idea is to keep the oil puddle on top of the spacer from going down into the area of the jets and fouling them. I've covered this some on another post.

[FordGuy81]

Thanks 12Ounce,

Normally, I use an entire can of seafoam through the PB vacuum line at every other oil change, or at least 3-4 times a year. I also use seafoam about every month or two in the tank. From reading posts on this site I just bought the Berrymans fuel cleaner. I'll see if that works better, plus its cheaper.

Also, has this ever happened to anyone else? When I was putting the plenum cover back on the second time, one of the bolts would not tighten and I couldn't get to back out either. I know I didn't cross-thread it. I deduced that the threaded metal insert(s) in the plenum had broken free, thus I can't tighten the bolt or remove it. Any idea how to get it out should I need to?

Thanks,

Bill

[12Ounce]

Some other posters have had the problem. Probably caused by overtightening somewhere along the way ...

I would suspect a small grinder, with a cut-off disc, could be used to remove the bolt head ... and go from there.

[FordGuy81]

So tonight I went to the store and decided to check and see if there were any pending codes since I did the work about a week ago. The CEL is not on, but the codes are pending.

Even though the isolator bolts had been replaced by the PO, I went ahead and replaced them, along with the O-ring gaskets, anyway. I did not torque the bolts, but I made them snug. EGR ports were throughly cleaned, and all vacuum lines on the back were reconnected. Other than a slight shudder from time to time, engine runs great.

Is there anything else to cause both these codes? Would these codes cause a shudder from time to time? Will these codes harm anything until I get time to look into it more?

Thanks,

Bill

[Craigford]

Can you explain about the isolator bolts? Where are the bolts located and what is the problem they cause? I have the same codes 0171,0302.

[FordGuy81]

Originally Posted by Craigford

Can you explain about the isolator bolts? Where are the bolts located and what is the problem they cause? I have the same codes 0171,0302.

The isolator bolts are located between the two halves of the plastic upper intake manifold. It is best to remove the wiper arms and the plastic cowling at the base of the windshield before attempting to remove the upper intake. There are quite a few threads on this forum relating to the isolator bolts and how to fix them.

You must realize that the isolator bolts are only one probable cause for code P0170, which is a Bank 1 (I think) Lean code. This means there is shortage of fuel or an unmetered air source (vacuum leak) somewhere on bank 1. Fixing the isolator bolts may or may not fix the P0170 code.

I was not having an issue with the isolator bolts when I replaced mine. After a lot of testing trying to figure the source of my misfire, I decided to tear off the upper intake to get to the fuel injectors. The isolator bolts had to come off to get to the fuel rail, so I just replaced them then.

P0302 is the code for a misfire on cylinder 3. In my case, I had a faulty fuel injector that was not firing causing the cylinder to misfire and trip the P0302 code. I spent quite a bit of time tracking down the source of the misfire. Only by moving the #3 fuel injector to cylinder 5 and seeing the code change to 0305 that I determined that the fuel injector was bad.

Besides a faulty or clogged fuel injector, the misfire code can also be caused by a faulty sparkplug, sparkplug wire, coil, or bad communication between the ECU and the fuel injector. A commpression leak at the indicated cylinder can also cause a misfire.

[mdare35]

Had same codes and problem with my 2000 Windstar w/ 3.8. This discussion definitely help me determine the problem and fix it. Switched wires 2 & 6 with no change. so then bought a new injector and changed #2's and it's running fine now.

I also found this site that had some helpful trouble shooting info for this problem and others.

http://troubleshootmyvehicle.com/for...el-injectors-1

So I checked the resistance of the new and old injector when cold and they were pretty much the same. However my rough running didn't happen from a cold start, it took 4-5 miles of driving before it started, I thought maybe my injector was ok until it got hot. I considered swapping the suspect injector with a different cylinder but I didn't want to have to assemble everything to test and then disassemble a second time to replace it if it was the problem so I just went ahead and replaced injector #2.

Luckily that did fixed it, and even better I had a cold beer or 6 waiting!