Code 171/174 question

With my '02 Windstar, late last summer it started "hiccuping" at speed. Didn't throw any codes, just hiccuped or stuttered once and a while. Asked my mechanic friend about it and he said plugs-and-wires. Put it off and put it off, then when it got cold, the problem disappeared. This lended credibility to the plugs and wires idea because the moisture dropped from the air. Fastforward to February, we had a thaw with a lot of rain and the problem re-appeared, this time with codes: P0303. Same mechanic confirmed plugs and wires, or possibly coilpack or injector. Plugs and wires being the simplest and cheapest solution, I chose that route.

CEL didn't go away, and new codes were P0171/0174. (Dramatic Chord) My question is: does that make sense, or did I likely knock a vacuum line or something off when I was changing the wires. Lord knows the back 3 aren't exactly easy to get to. Incidenltly, the engine still mis-fires (according to the CEL) quite frequently, and does run rough, both at idle and to a lesser extent at speed.

Checking into the 0303 error after the plugs were done leads me to think the coil might be the problem, but not for the 171/174 issue. So, are the 2 linked? Did I just have to relatively common problems occur at the same time?

Thanks in advance.

Z.

P.S. Thanks for taking the time to read my rambling story.

well you could have knocked a vac line off when you were doing the plugs. Also there could have been a vac line that was a bit weak and the jostling around with the plugs, wires caused a crack to open. It could also be the 171/174 egr plugging discussed fully here too. I'd be taking a good look at the vac lines, likely with the cowl off (sorry) and seeing. If not, maybe the 171/174 cleaning is indicated.

Piper

Take a look at the P0171/174 sticky post at the top of the windstar room.....and see if this has been done on your vehicle.

There have also been some posts where folks have had the coil pack fail.....

As far a the fuel injectors, they are VERY reliable on the windstar.
HOWEVER, as I mention in the "General Windstar Information" sticky post, they tend to build up dirt over the spray end......the ONLY thing that I have had success with, that you can get at the local auto part store is Berryman's B-12 Chemtool.....in the metal can.
Add a can to a 20 gallon tank of fuel (if you have the optional 25 gallon fuel tank.....you will need to add more).
If you have not done this before.....it may take up to 3 treated tanks of gasoline to clean the injectors up.
The good news is, the Berryman's is one of the less expensive of the multitude of fuel cleaners that you will find on the shelf.

Another thing......change the fuel filter.....this is often overlooked.

This is all routine maintenance....and should be done before looking for a complicated solution.

This is in ADDITION to double checking the vaccum lines as already advised.
Give the 90 degree elbow on the top of the upper intake manifold a look.....the one next to the throttle body that goes to the PCV valve (front valve cover on your year).
Mine developed a crack on the inside of the elbow.

I did check the vacuum lines with the cowl off, err...at least I checked for what I hoped would be glaringly obvious. I am not entirely sure if I know what a vacuum line looks like beyond "grayish black tube like thingy", which describes most of what is under the hood. I looked around where I was reaching for the plugs/wires and didn't see anything.

I have done some injector cleaner in the past, but not that brand, so I'll try that, and the fuel filter.

I did notice last night that periodically there is a loss of power when accelerating that returned just about the time I noticed it was going slower that I thought it should. It felt kind of like how it feels when you force a downshift to pass someone, but I don't think the tranny downshifted.

Thanks for the advice. I'll post after I have tried this stuff.
Z.

I forgot to ask: I read, I think it was on a scan of the TSB, where it talked about occuring when it was warm out with winter grade gas, and that using higher octane gas could resolve it. Does this make sense? What about using an octane booster instead, would that have the same effect? Am I just way out in left field and babbling like a moron?

Z.

I'm not big on octane boosters.......better to use a higher grade of gasoline.
Octane boosters that say.....raises octane by x points......means 0.x octane increase......not very much.....and I don't trust the additives used......and is more expensive than just using a higher grade of fuel.
However, the windstar seems to run just fine on 87 octane gasoline.

There is the case where excess oil has been drawn in over a period of time.....due to a issue with the baffle in the front valve cover on 1999 and maybe 2000 3.8L motor......causing a carbon build up inside the cylinders......
This causes higher compression.....and pinging which requires a higher grade of gasoline to correct.
FORD's solution is to reprogram the PCM to delay the timing slightly to correct for that.

A slightly lean fuel mix is the normal cause of the pinging......with a vaccum leak being a leading cause.......dirty fuel injectors and fuel flow also possible.

I have noticed.....on my old '96 3.8L a VERY SLIGHT pinging on normal non-10% alcohol mix gasoline.
It normally runs around on the oxygenated, 10% ethanol, gasoline....and does not seem to have the pinging.....and it may take a while for the PCM to "adapt" to the different fuel.....
Don't know......and....as I said.....very slight......so not of concern....as NO other drivability issues are noticed.

I DID forget to plug in the Throttle position sensor once.......and got a CEL....and the transmisison did not drop down when I punched the accellerator.

To check for vacuum leaks get a 3 foot long piece of 3/8" fuel hose from the auto parts store. With the engine running put one end to your ear and move the other end around the engine compartment. It will greatly ampliphy the hissing noise when you get close to the leak. Just stay away from the belt and the radiator fans.

If you have not replaced the Insolator Bolts according to the 171/174 sticky I highly recommend it. The gas mileage in our van went up from 16 t0 18 mpg.

Also, I could hear the vacuum leak between the upper and lower intake manifolds on my van using the 3/8" hose prior to the insolator bolt repair.

You should also remove your coil and check it closely for cracks. Very common on these vans.

To check for vacuum leaks get a 3 foot long piece of 3/8" fuel hose from the auto parts store. With the engine running put one end to your ear and move the other end around the engine compartment. It will greatly ampliphy the hissing noise when you get close to the leak. Just stay away from the belt and the radiator fans.

If you have not replaced the Insolator Bolts according to the 171/174 sticky I highly recommend it. The gas mileage in our van went up from 16 t0 18 mpg.

Also, I could hear the vacuum leak between the upper and lower intake manifolds on my van using the 3/8" hose prior to the insolator bolt repair.

You should also remove your coil and check it closely for cracks. Very common on these vans.

I do know that the iac will huccup when you goto park to drive and start moving. This is a sign of a weak iac. Turn the air conditioner on and try it from park to drive and give it some gas. It will huccup like 4 5 times in a row too. With those new leak codes, I would check into the intake or vac lines first. Since you changed your plugs, it changed the timing of the fire, Not by much, but enough to notice a difference if they were worn down alot. Now that its the correct timing, you get a new code that it can understand. PCM