Timing full throttle after TDC

[vipersinu2]

when at Idle about 5 degrees before TDC and to full throttle it appears that the timing mark goes past TDC to after TDC about 5 degrees? anybody can help me out with this.

no power till 2000 rpm then the truck will kick in and actually spin the tires on the dirt road.

when I unplug the mass air flow sensor the tuck runs better. This is the third sensor, I keep taking them back to autozone, and each sensor makes the truck run different

no check engine light

 

[vipersinu2]

And the problem was................... Autozones's mass air flow sensor did not set the computers correct timing, and I tried four sensors from autozone all no good,

the factory ford mass air flow fixed the problem, the tech even said if i buy the part from ford dealer that there will be no charge for the diagnosis (he even put 10 updates in the computer) or labor putting the mass air flow sensor on, Great deal in my book I went nuts for two months trying to figure this out.

 

[vipersinu2]

Dealer did charge for diagnosis $95.00 and mass air flow sensor 220.00, bigger bill than I thought 315.00 plus tax. and problem still there, full throttle is going to 17 degrees after tdc and loss of power, all the ford techs were stumped and the the best they can do is send ford corporate an email for advice. great service gotta love it. :thumbdwn:

 

[matt0248]

If timing is being retarded that much there may be a problem with the knock sensors picking up engine noise or the knock sensor is bad. :my2cents: Or is there are Cam or Crank sensor problem? Is this a 4.0L? They have harmonic balancer issues, the crank sensor trigger wheel is on the harmonic balancer. Other possibilites, timing chains not installed properly, jumped one tooth or streached? Ignition timing is all computer comtrolled and calculated using the cam and crank sensors, coolant temp sensor, and the knock sensor. The MAF, i think, only affects A/F ratio not timing.

An easy test would be to disconnect the knock sensor/s to see if the problem goes away. Any good Tech with a graphing scope/meter can check the cam/crank signals to see if they are timed properly with respect to each other and of the proper waveform.

Another thought. get in touch with James Henson 2 hensonperformance.com, he is a vendor on this site and tunes explorers. He should be able to tell you what things can affect timing and what stock timing should be. Also, just because you have new parts does not mean they are any better than the ones that you replaced, as you experienced with your MAF sensors from Autozone. I had issues with Autozone IAC valves. got a motorcraft one problem solved. :another2cents:

 

[vipersinu2]

Matt I did unplug the knock sensor and it did run worse.
the engine is out of a 2010 ranger that was crashed and had 2000 mile on it, when the tech had it on the computer all levels for air and fuel mixture were perfect, I tried 3 harmonic balancers and no luck, the tech also said that if the timing chains were out even a hair it would not idle properly, the truck idles perfect. but I will try to get a hold of james henderson,

I did go down to the dealer today to review the email from ford corporate

the letter stated that since the truck is 2003 chassis and I put in a 2010 engine that ford will not trouble shoot or support, they also said that the cam,valves,knock sensor, and compression are different between the years.

the lead tech pulled specs on both engines and they were the same so the email was bull crap, and stated there is nothing they can do to help or repair, he recommended me to get a chip or programmer to fix the timing, or just drive it the way it is!

 

[vipersinu2]

problem solved

2003 explorer spark plug (shorter) compared to 2010 ranger spark plug (longer)

My engine donor was from a 2010 ranger with the longer spark plugs. I installed a new set of spark plugs for a 2003 explorer which are shorter. I never noticed the difference in length. I Installed the orginal 2010 spark plugs and studdering went away, I put on 20 miles and all seems good

 

[Javadog123]

Good find. Glad you didn't throw away the old plugs. You may have never figured that out otherwise.