Strange Drivability Issue?

[Lazzman]

Hmmm, I have been experiencing this somewhat strange problem ever since I installed my Cold Air Intake about a year ago.

Off idle and under mild Acceleration the engine runs really great, however if you dip into the gas at casual cruising speed, say around 35 or 45 mph
the Tachometer will jump to 3000rpm and hold there. If you continue to push the accelerator down further the engine appears to hesitate or bog and the tachometer will only climb a couple hundred more rpm's to 3400. You can hear the airbox trying to suck air as the acceleration seems to bog out.

If you keep your foot in it, it will last about 2 seconds before the engine is able to overcome what ever is going on and start to rev up the RPM range normaly again.

If you put the pedal to the floor at any time during this situation, the transmission will kick down and put the engine into WOT, where there is no bog issue.

Sometimes it is worse than other like during damp days, sometimes the engine will just rev up through the RPM range normaly without hanging up at the 3000rpm range.

At first I thought this was a sensor but I have replaced most all of them with little results, scanners have not been able to pick up anything either, iginition and fuel components have either been replaced or checked. I am thinking that it may be the transmission, as I have noticed the tach slipping lately.

I have heard others complain of this problem but have not heard what the overall outcome was.

Does anybody have any idea what could cause the engine to hang up in the 3000 rpm range under heavy throttle, in open loop (running off the sensors feedback - not WOT) ? Trying to apply more gas just bogs the motor more, until it can finaly overcome what ever is happening and continue to rev.

It was once described to me by a mechanic as hanging up or stuttering around the 3000rpm range. Though he could not figure out the problem.

The idle is also low to as if the a/f mixture is way to rich. Very responsive off idle to about 1/3 pedal, once you goose the gas it will jump to that 3000rpm sticking point and hold.

If anyone has experienced a similar situation or has any suggestions I would love to hear from you.

Suggestions and positive advice only please, the extra flogging and sarcasm is not needed. Especially after investing $$$$ over the last year.

The $60,000 question is: What would cause the engine to hang up at this rpm point and eventual overcome up after a few seconds???

 

[aldive]

My suggestion is to diagnose the problem in a scientific manner. Don't simply replace components ( sensors et al ) because someone suggest doing so.

If I suspected an A/F issue, I would data log the A/F ratio and see what is really going on.

The alleged bogging issue should be data logged as well.

With real data one can diagnose a problem.

 

[Lazzman]

Yes Al you are correct and I appreciate the excellent suggestion.

I wish I had the money to invest in the scan tool. That is one thing that none of the mechanics I have take it to have done.

One guy had the scanner on with just the truck idling and was able to detect a faulty coolant sensor, but he did not go through the rpm band, I guess he was either lazy or did not feel it was worth it for him.

I wish I took your advice a year ago and bought that scan tool. The dyno shop I am going to is also a custom speed shop with good mechanics, I had trouble explaining the problem to them last year but I won't this time around.

 

[aldive]

You need to datalog, not scan.

 

[Lazzman]

I am tempted to go and buy a laptop and the software. The truck drives awesome for its age, that is why I am such a big fan of this site.

If I could iron out the last problem, things would be golden.

 

[Lazzman]

How do I data log the information Al?

Back to the original Question, has anyone had a similar problem or can make a suggestion as to what the problem is?

 

[Turdle]

here is a link to another good scantool, but more importantly--if you scroll down the page to where it says "just in time training"--right under some downloadable link---

there are 3 training videos--and they are free. Not only that, they will explain quite a bit. I suggest going through them, then again when you get your tool.

http://automotivetestsolutions.com/escan.htm


I tried to pm this to you but your box is full.

 

[Millertime1987]

I am sure this was done when you installed the intake but how about disconnecting the battery leave it that way for a while (20-30min) then reconnect. See if the computer needs a reset with the new intake in there.

 

[NHale623]

Hmmm, I have been experiencing this somewhat strange problem ever since I installed my Cold Air Intake about a year ago.

Have you tried to restore the air intake to the stock configuration to see if the problem still exists?

 

[aldive]

How do I data log the information Al?

Use an SCT Xcal II hooked to your truck and also hooked to a laptop computer running SCT's Live Link software.

 

[aldive]

I am sure this was done when you installed the intake but how about disconnecting the battery leave it that way for a while (20-30min) then reconnect. See if the computer needs a reset with the new intake in there.

Even if he didn't do this, the PCM's adaptive learning whould by now corrected.

 

[aldive]

here is a link to another good scantool, but more importantly--if you scroll down the page to where it says "just in time training"--right under some downloadable link---

there are 3 training videos--and they are free. Not only that, they will explain quite a bit. I suggest going through them, then again when you get your tool.

http://automotivetestsolutions.com/escan.htm


I tried to pm this to you but your box is full.

Jon, do you have this scanner software? Looks like a very nice product.

 

[LMedina]

Aloha my friend. EXACT SAME THING happened (still happens on a regular basis) when I installed a K&N FIPK GenII. That's right: engine revs (more like 'surges,' right?) to 3000rpm before getting back to normal.

Now, I also have the faulty transmission, the one with the trans flare between 2nd and 3rd gear (there are dozens of posts on this tranny subject; go do a search). The symptoms are identical (I've never gotten the tranny fixed because it's still very drivable and I can live with it. I can't live without the $3000+ it would cost to fix it, though).

So in my case (and hopefully not yours) it could very well be the tranny, and the installation of my FIPK at the time of my tranny's malfunction could be a coincidence, however:

I have read that the increased air volume may "confuse" the SUV's computers, causing them to attempt to compensate for the increased airflow. How this might affect engine RPM I don't know;

I have read that the filter oil applied to my FIPK cotton gauze filter collects on the mass airflow sensors, also affecting the way air volume is read and so confusing the computers that are attempting to compensate for the false readings. I have sprayed MAF cleaner on the sensors with no improvement, though.

I have not attempted to put back the original filter housing to see if the problem goes away. At most the problem is simply quirky and I can live with it so long as it's not causing anything castastrophic and still allows me to get to my favorite dive spots.

Try emailing the maker of your air intake and see what they say about it. (I, ever the slacker, have never contacted K&N, or even Ford, about my engine flare problem).

 

[Lazzman]

Thanks for the info.

In regard to your tranny problem, It is in the valve body. Your entire tranny does not need to be rebuilt.

I had a new high performance valve body put in for $500 at a good tranny shop near my home and no more 2-3 flare.

 

[LMedina]

Aloha Lazzman, THIS is why I don't bother asking Ford for help, because I get REAL answers right here on this website! All the info I posted for the guy with the trouble was humbly subquoted from other forums I've read here. I hope he can do a search for the actual posts which I have long since forgotten.

Thanks VERY VERY much for your tip - I have always dreaded the high costs other folks have paid to get the whole damn tranny rebuilt, and STILL have the 2-3 flare problem after!

What brand/make valve body was put in yours? And how long was it in the shop?

This is where my tax refund will be going (since this fix is much more affordable) and I better throw some money at this site to support it and keep it going! I will definitely go with your advice and post my results for others to read. Mahalo. //LMedina

 

[Lazzman]

The tranny shop I used was very quite about where they were getting the VB from, but I am sure any shop can get it for you. The VB was $300 and they charged $200 to put it in,which took about 2hrs.

I think the owner of the shop is koi because he does not want "do it yourselfers" ordering it and putting it in themselves.

Even if you can't get one there are some very good rebuilds descriptions on the board, using ford upgrade kits.

Do a search on Valve body rebuilds.

Though I know the rebuilt one is pretty easy to get, just have your shop do a search for the rebuilt VB for a Ford 5R55E Tranny.

 

[aldive]

bump