Check out my latest post. Symptoms sound pretty close. Verdict: recessed valve seats.

 

god i hope thats not my problem lol. will check out thread. Also Ron, i did the coil pack thing and it didnt throw any codes. was i supposed to do it when it was completely cooled off? I also unplugged one cylinder at a time from both packs. It was sucking my hand in but it had a wierd tick that doesnt happen normally. but as soon as i plugged it back in it went away.

 

I just had a theory. Before i changed my lash adjusters, i never had this problem. what if they were weaker and they weren't getting as pumped up as they should. the new ones might get pumped up better causing the valve to stay open. am i thinking of that right?

 

Lifter force is only going to be affected by 2 things: oil pressure and bore size of lash adjusters. The lash adjusters themselves aren't weak or strong.

I got a reman head in today, due to the shop letting me know the head had too many small cracks to fix. I was wrong on my original measurements for valve recession. It was actually worse because a valve shouldn't be flush but they sit 0.050" taller than the valve seat when "new". So this set mine up for 0.080", 0.070", 0.050", and 0.050" of recession respectfully. Ford lash adjusters according to what is online have a 0.060" stroke length. So for the first two cylinders mine could have been bottoming out (depending on the expansion of parts due to heat, I bet there is a hair more slack in there). Compound 270k mile valve springs and 0.080" of valve spring relaxing can make some weak pull force on the valves. Using the specs for valve spring force at different lengths it averages about 162.5 lbs per inch. So the 0.080" relaxes the spring by 13 lbs (that seems pretty significant). Maybe the higher millage has weakened the springs enough for a total loss of 20 lbs? Also add in that the ratio of leverage in the followers looking at the cam as the pivot point. Seems like the lash side is farther away from the cam than the valve. If that is the case a 20 lb loss of spring force is amplified to the lash adjuster. So the lash adjuster has 24 lbs less force to over come.

When I get a chance I'm going to go through all the math. I need to take an HLA apart and see what the bore size is to get a reading on how much pressure can be exerted.


I think your best bet is to figure out which cylinder is bad. Get it running like crap and either pull a whole coil pack and start pulling individual spark plugs off the active coil to determine which cylinder isn't contributing or just pull an injector connector to see if it makes a difference in the idle. Once you determined a cylinder, hookup a compression gauge to that cylinder (easiest access is on exhaust). Then hook a gator clip jumper wire to that spark plug you just pulled's coil tower to ground the spark (leaving it open can damage the coils) and keep the driver side coil unhooked. Pull that cylinders injector connector. You want to turn that cylinder into an air pump. Start the car and rev it to kill it. As soon as it dies. Hit the compression release on the compression gauge to zero it and crank the car. If your's is recessed valves you will have a low reading as the HLA's should still be pumped up and haven't bleed down yet.Got to be quick because they bleed down anywhere between 5-15 seconds.

 

Thanks for all the details Shelton

When you get yours done, I'll be interested to hear the rest of the story. Good luck to you!

With mine, I didn't get any misfire codes like you guys did. P0102 is all that came up (low voltage at MAF).

I was on a trip last week, so I still didn't figure out how to test the MAF... I already cleaned it, but that didn't help.

I'm so tempted to just throw a new MAF at it, but I've wasted money like that before...

 

Here is how to test the Ford MAF sensor with a multi meter

https://easyautodiagnostics.com/ford...sensor-tests-1

 

Thanks Rock! That looks simple enough, I'll post what I find...

 

Thanks again Rock304, you might've save me 90 bucks..

I did 3 of the 4 tests as described in that link... I skipped the third one because there was a chance of frying the computer..

The instructions for the third test said:

It seemed strange to me because it warned about shorting the "C" wire to power, and then it wanted me to test it to the positive side of the battery... I had a "WTF" moment, and decided to skip that test (just in case it's a misprint or something). Also, it didn't specify "key on" or key off".

In any event, that test would only exonerate the MAF sensor. If it failed that test, then the problem is elsewhere.

So I skipped forward to the last test, which is the only one that actually tests the sensor itself, and it looks like the sensor is working correctly on mine.

That article gave a great description of how everything works, but I'm wondering why the last test wasn't done first. ...The first three tests were just checking the power supply to the sensor, and only the last test checked the sensor itself. Why isn't it done in reverse order?

 

Here's the results I got on the "D" wire test (the last test).

The baseline number was around 172-175, and it went up steadily when I revved it slowly. Then It settled back down to the same range.

For the vid, I had to just rev it up quick then get the camera back to the multi-meter... But it looks like it was doing what it's supposed to...?


https://www.youtube.com/watch?v=lfbl...ature=youtu.be

 

...I should've specified, that baseline number was 172-175 mV

Now that I googled it a little more, I see that the baseline number should be more like 600-800 mV at idle. (0.6 - 0.8 Volts)

So maybe this will be a simple fix after all?

 

After searching a bunch of vids and not finding anyone doing the same test, I just said a little prayer and went ahead with that third test. It was a little nerve-wracking, but it worked fine. With the ignition off, that "c" wire showed 12.3 volts (same as the battery).

On the fourth test it said;

"...Once the idle stabilizes, take a look at the voltage number or numbers your multimeter is throwing at you. This voltage may fluctuate a little or a lot, and this is OK. Whatever they're doing, this is your base MAF signal voltage.

Now, open the throttle (manually) to rev up the engine. As the engine revs up... keep your eyes on the multimeter's voltage numbers. The voltage should increase.

When you let go off of the throttle and the idle comes back down, the voltage reading should also come down and should hover around the numbers you noticed at the beginning of this test."~

At first, that led me to believe that 175 mV was ok. ... But now that I looked it up, I see that it's supposed to be much higher than that.

I just put a new air filter in it, so I can't imagine what else could make that number so low. I guess I'll change the MAF sensor soon...

 

Just throwing this out there. Has your car been in an accident?

My 2006 was a salvage that had been fixed up. Though it looked and acted like it was in excellent condition, there was a wee bit of a problem that sprung up on me after 8k miles.
My engine wasn’t starting. It would catch sometimes then shake and shut off.
I tightened the battery cables and it seemed to like that? But a week later, within three minutes after my car was parked on a forward angle my car shakes and shuts off. I then got it towed and being on the tow on a upward angle it started working and worked for a solid couple of days. Until I filled it up with gas and parked it on that same forward angle. I’m so my initial thought was fuel pump. (Which I was lucky to find out that was not the case) Upon further diagnosis we found that it was the inertia switch. It sends signals to your fuel pump to shut off after a car accident. Ford changed the model and position in my model so, maybe check that out?

-hope I helped!

 

Thanks for the update on what you found. It does sound like a MAF sensor gone bad. I feel the same as you about doing some of the tests but I did them anyways on mine and mine tested OK. It was replaced before I bought it but with anything electrical you just never know. Let us know if a new one fixes your problem.

 

Fixed it instantly. Wish you luck.

 

Sure enough, the new MAF sensor fixer er right up! She purrs now.

Aside from the stalling, I thought she was running pretty good... But everything seems to be just a little smoother now. It used to "hunt" a little bit, but she's smooth as silk now.

Thanks again for that link Rock304, it helped a lot!
Here it is again, for anyone who wants to try it;
https://easyautodiagnostics.com/ford...sensor-tests-1

To that link, I would add two things;

1- On the third test, you don't even need to put the key in the ignition. That wire showed the same voltage as the battery (with the bad sensor in place).

-2- On the fourth test, it DOES matter what numbers you get.

The directions say it doesn't matter, "it's just a baseline number", and you're supposed to just reference from it... but that's not correct.

On mine, the number was way low. Everything I found said the "baseline range should be anywhere from 0.6-0.8 volts, but mine was showing less than 0.2 volts as a baseline.

Mine did respond smoothly to throttle input, but that voltage reading never went above 0.27 volts.

With the new MAF installed, engine warm, I now have 0.92 volts at idle.

If I ever come across this again, I'm gonna just go straight to that fourth test. ... If it fails the fourth test, I'll go back to the first three; just to rule out the wiring.

 

One other detail about the symptoms mine had...

When I first start it up, there was no stalling. Only after the temp comes up a little, she would start stalling.. But would always fire right back up..

The guy at my local Napa explained it to me, and it made perfect sense.... When the engine first starts, it doesn't use the sensors. It runs on a pre-set code. And that's why the faulty maf sensor doesn't affect re-starts.

 

I also have these problems with my 1997 2.3 liter when I bought it ran fine that was the summer,when it gets cooler it never gets to 190 degrees...changed thermostat....heater hoses and top rad hoses hot,bottom hose cool how about yours///

 

I'm not sure... I would expect one hose to be a little cooler than the other because it's coming out of the radiator...

If yours never gets up to temp, then that means the thermostat isn't closing. Or maybe you got a thermostat that opens at a lower temp?

In any event, I think the computer is supposed to compensate for cold weather... even when the engine is still cold...

I would recommend checking for codes. Even if the check-engine light is off, there still might be codes stored. If you don't have a code reader, some auto parts stores will read the codes for you. I got mine read at Auto-Zone.

Also, when you first turn the key on, but before starting the engine, you should see the check engine light come on. That's how you know it's working.

The computer has sensors for intake air temperature and coolant temperature, so I would suspect those for starters... and they're easy to replace, if needed.

Good luck to you!

 

You're welcome! I'm glad you got it fixed.

 

so I've been driving it for a while since i don't have time to deal with it at the moment. It does pretty good when i start it in the mornings but coming home it does it pretty bad till it warms up. When i get time to investigate further ill wake the thread up again. (to be honest i forgot this thread existed I've been so busy lol)

 

so i just received my FORScan adapter today tomorrow ill run some tests and see what i can come up with after more research im leaning towards recessed valve seats.

 

Any updates on the possible recessed Valve seats?

 

I ended up getting forscan, i turned on live data misfire counter it counted a crapton of misfires after i let off the gas, and quit counting when the engine was running good again. i also looked at mode 6 misfire rates and one cylinder was way high if i remember right. forgot to post after i checked so thanks for the reminder lol. ill post some pics of my forscan if i took screenshots.

 

I dont really know what most of this means so if someone could explain that would be wonderful.
Ive just been driving it, as it seems to be doing fine. It does seem happier if i let it warm up to full operating temperature before i start driving.

 

Thanks for the update!