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Well maybe you can get a mechanic friend to check the pressure for you. On their lunch hour, so to speak. I expect that most shops bill a minimum 1/4 hour, so having it done would be close to the cost of the gauge.
Does removing and attaching the vacuum line to the pressure regulator have any effect on the exhaust? Removed, the mix should go rich and possibly give black smoke.
tom
Does the engine idle smoothly when it's warmed up? Yes Does it have a 'fast idle' when cold that steps down as it warms up?Yes
'cuts back when accelerating' to me points to a MAF that is not working just right. You can try to run it with the MAF disconnected (will throw a code, I'd hope..) and it will 'deduce' what's going on and use 'middle of the road' numbers for fuel/spark, etc. Will try.
The idle problems may be a vacuum leak as the P0171 was a 'lean' code.
Remember, the O2 is dumb. When it says 'lean' that means there is EXTRA O2s in the exhaust ... they have not all been used up by combustion. Why? extra, unknown air, or even a misfire - which will leave extra O's .. or an actual LEAN condition. The computer only has a few things to go on. If ONE cylinder had 'extra' air that it could not use up, or, as happens in the Windstar 3.8, EGR passages that get gucked up, (in the bottom of the intake right before the intake valves) ALL the EGR flowed can end up going into 1 cylinder, or enough to cause misfire ---- leading to a LEAN code even though ... and the computer adds fuel for ALL cylinders ... what a misleading code, eh? Yup
Anyway, check the PCV & hoses.Replaced them all and rechecked them Did you change all the plugs or just the exhaust side? All 8. I asked about idle to know that the plug wires are in the correct spot as flipping can lead to noticeable idle misfire that can be hidden at higher rpms.All of them are correct.Double checked.
tom
Maybe disconnecting the battery will make the computer re-learn how things should be set now that you have functional O2 sensor feedback.
I ASSUME you did NOT have any idle change when spraying around the emissions hoses/vacuum lines. You said you got change, but did you mistype?
tom
Some time back, you reported: "I get no misses or skips at idle or free reving to any rpm and holding it there.I also ran a tank of fuel out yesterday and filled up at a different locations just to take that out of the equation.Since our area started with the 10% to 15% ethanol blended fuels,I can't run anything under premium 92 or 93 octane without having serious spark knock."
***
Adding ethanol to the mix will raise the octane to my knowledge as the ethanol puts out less BTU/volume, and would work better with a higher compression ratio. Again, what I've read.
You should not have spark knock with 87 octane with <=10% ethanol.
It runs smooth at idle and will rev up smoothly, per above. Only when you put a load on the engine does it start to mis-behave. When you put a load, it will demand more fuel, which it was previously getting in buckets. Once you replaced the FPR and the O2 sensors you said it ran better, but not quite right.
Does it still pour out black smoke? Not as bad.Occasionally under heavy load it will barely put out black smoke.I had to follow the truck to see it. Get 9 mpg(or ?) vs the normal 300+ per tank?I am up to 250 miles to a full tank.
Have you checked the TPS for good resistance as it could be misleading the computer, so it would not know the proper amount of fuel to flow? I don't have the specs and my Chiltons service manual don't have anything on it. In most cases, 'falling on its face' is a fuel delivery problem or a MAF that is lying to the computer or has 'stuff' on the wire(s) that biases the reading.
A good smooth idle cannot be produced with bad valves / rings, etc. So the basic engine should be good. You replaced the belt, but I never heard that you had checked for the triangle on the cam sprocket to be 'at' the pointer behind the belt cover at TDC. Is it there? The cam,crankshaft,and oil pump are all timed properly.Triple checked. If not, you'll have an engine that runs poorly, or will be gutless until it reaches higher rpm. If you have checked it, ignore, but if you haven't, it is definitely worth while. When I have done these, I found I had to rotate the crank a couple turns after install to make sure all the 'slack' got on the tensioner(water pump) side of the belt, otherwise things didn't work right. I also tried to set the timing (dist) and must have missed the 'static' window advertised where the SPOUT jumper could be left in. Re-time, and the difference was amazing.
Don't give up. It has served you well for a while, and doesn't deserve to be squished. If not you, then someone would get good use, and maybe be very happy.
tom
If you would be so kind, please summarize where things are now... mpg is better, smoke is better, what is it doing? what is it not doing? List all bits & pieces that have been replaced, symptoms you can describe, how it runs at different rpms/loads.
Too many posts to keep it all in my head, so it would be a help to me & others to get a good summary...
tom
Two ?'s ... is the fuel mpg still poor and is the MAF new or used ... What happens with the MAF disconnnected? Most times 'accelerator pump' type reactions are MAF related. The MAF may not be heating up or cooling off properly, or base volts could be off .. leading to incorrect MAF info to the computer. Air flow increases as soon as you goose the pedal, but fuel, in carb circuits/passages, takes a bit longer to get up to speed, thus the momentary enrichment by the accelerator pump helps the transition. Goofy MAF will lead to hesitation on acceleration.
I don't remember if the CTS and ACT sensors have been checked. Coolant and incoming air temps will lead the computer to fiddle with the mix. They'll put out a variable resistance based on temp. The TPS should vary in its output also, IIRC, up to about 1 volt at WOT, and less, in a smooth transition, as the throttle is closed. Ford may have changed from the system I remember.
tom
When you installed the Delphi MAF did you disconnect the battery so the system would learn of the 'new' part and its characteristics? Dunno, but it may need to do that to know what kind of airflow is being fed.
If you have a MAP, it could be causing the idle to jitter and jump. It monitors manifold vacuum to 'know' the load on the engine and adjust fuel flow accordingly. If bad, they will give a terrible idle quality as the injectors will be doing the cha-cha as far as fuel flow.
tom
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