A few weeks ago I had a thread on here about my 2.5l pinging, after changing the maf the problem was solved for a month or so...but now its back to pinging although not nearly as bad. Once warmed up sometimes it will ping other times it wont...its just a toss up. So far I have:

-Changed plugs and wires
-Changed MAF
-Cleaned EGR tube and valve
-Checked for vaccuum leaks (there are none)
-Seafoam'd the engine
-Ran premium gas (even added booster to the premium)
-Checked fuel pressure (62-65psi)
-No codes at all
-Im sure there is more than I am forgetting

Either way the truck was running great with no pinging after I changed the mas air meter but It is pinging again so I hooked up my buddies Predator to it and it shows my fuel pump duty cycle averages 65-70% at the first sign of me touching the skinny pedal. It goes as high as 80% but just cruising around giving it barely any gas the pump its never lower than 55-60%. All of this is without any WOT at all, just the slightest bit of gas.

I know that once you get to around 80% its not good, but does anyone think my pinging has anything to do with a failing pump? To my knowledge the timing belt has not been replaced, I am the 3rd owner and have no service reciepts. The owners manual says to inspect it at 120k miles and the truck now has 1295xx on it. It is my understanding that the tensioner will take out any slack in the belt and since timing is non adjustable on these motors that the ping is not caused by that....true or false?

Here's the link to the previous thread from last month
https://www.ford-trucks.com/forums/8...ml#post7852146

 

No one has any input??

 

If you still have good fuel pressure then I wouldn't find reason to suspect the fuel pump. As far as the belt, it is possible for a very old timing belt to skip a tooth or two, but I would think you would notice more than just some pinging if that were the case.

 

Knock sensor?

 

I've read a few posts that mention fuel filters (including your first thread).

From what I understand, you can have pressure without having volume. There's a test for this, but it's probably easier to try a filter.(except for the bleeping connections).

By fuel pump duty cycle -- do you mean injector duty cycle? I THINK that you have a return type fuel system in which case the pump is always running.

If its injector duty cycle, then it would seem that the computer definitely thinks that it isn't getting enough gas.

Please understand that these are just theoretical ramblings...

 

I honestly dont know...I always thought that duty cycle only referred to injectors, but my buddy that has the Predator (works on all ford obdii systems) was the one reading it while I drove. I cant believe that the injectors would be at almost 80% duty cycle on a stock tune so I went with what he said and that it was fuel pump duty cycle...

I agree about the belt slipping a tooth, if it did I would have other problems besides just pinging and clattering once warmed up and in open loop. g_k50 from all the post readings I have done on various boards and google searches I have come to the conlusion this motor does not have a knock sensor. I have not been able to locate a sensor for this motor on any parts search.

The temp dropped quite a bit today so when I came from work an hour or so ago it was about 60 or so out and once I got halfway home it started pinging and clattering like usual. Living in the desert for so long I know some cars do it cause of the heat, but tonight it was chilly out and the fugger still did it...if its not the pump I am stumped on what it could be. I understand that belts stretch overtime, but if the tensioner is always keeping the belt taut then I dont see how my timing could be thrown off.

edit: its 2am and i just got home from work...I feel like crap and am coming down with soemthing so I had a few shots of whiskey to put me out, if anything doesnt make sense Ill explain better in the morning tomorrow

 

Pinging is basically caused by very few conditions
1. Lean fuel mixture
2. Timing advanced to far
3. Carbon in combustion chamber.
The OBDII scanner can tell you what the timing is it can also tell you if the o2 sensors are working correctly and it can tell you how much air it thinks it is taking in. You really need check all the pid data and see what is not within specs and work form there.

 

I like the idea to get some more PID data, & maybe take a close look at the short & long fuel trim numbers, MAF sensor, O2 sensors, Engine Temp sender, Intake Air sensor PID's before & after the ping begins.

Seeing as how your not complaining about driveability, or power loss & the problem is intermitent & only occurs after a long highway run when everything is all warmed up, it sorta sounds like a borderlne sensor, or maybe a vacuum leak opening up after everything really warms up, so the sensor PID's & fuel trim numbers should offer up some insight on those thoughts.

Seeing as how the new MAF sensor had fixed the ping last time & is the last thing messed with, maybe begin by looking at it's PID first.

Did you reinstall the oiled air filter, if so maybe it's contaminated the new MAF sensor, so maybe pull & reclean it with the CRC MAF cleaner.

Is the replacement MAF sensor a new OEM, or OEM reman, or is it an after market new, or reman, or a salvage yard unit????

 

It has never had an oiled filter on it, Im not sure where you got that idea from...its a new paper filter that was in the truck when I got it. The new MAF is a stock 98 maf w/ 25000 miles on it, my buddy totaled his 98 2.5l ranger a few years back and had some parts left over from it. I cleaned it and installed it and everything was good for a month or so.

I never got around to changing the fuel filter since the ping went away completely when I swapped the MAF, so Ill be doing that most likely on Sunday since Ive been down with a cold the last couple days.

What are PIDs?

 

Pids (process ids) are the values the the sensors are presenting the Ecu the maf will be in lbs per (hr min) something like that and there is a given range of Normal for each sensor. if a value get out of range over a given amount of time then it sets a trouble code and at some point will turn on the check engine light. By the symptoms you describe I almost fell like it could be as simple as carbon in the combustion chamber it gets red hot after extended highway driving and will cause the engine to ping without much effort. But that is just a guess. If some one has an OBDII scanner then take advantage of it and get some real time data of engine operation compare that to what is considered normal and work on solving ant=y thing it may point to. These modern engines will compensate for a lot issues up to a point.

 

With the carbon theory I have already done the Seafoam treatment to both the gas tank and the engine itself. I plan on getting some Techron concentrate and running that to see if it cures my slight knock on startup that goes away once the engine warms up...pawpaw was mentioning something about CCDI and that the Techron has been known to resolve that problem....maybe the Seafoam didnt help clean most of the carbon and so it still heats up and causes the ping? I dont know but there is only one way to find out and Ill be getting the Techron come tomorrow or monday as well as changing the fuel filter since I am getting over this cold now.

As for the obdii scanner, I have been using a friend of mine's Diablo Predator tuner/diagnostic thingymajig. He bought it for his old 1999 SVT Cobra but it seems to work on pretty much all obdii Ford vehicles. He's used it on his 1999 2.5l Ranger, 2003 3.0l Ranger and it seems to work on my truck as well. While I looked on the diablosport website for compatibility with my truck it does not list one as being available for my model...the only Predator they have that is listed as for Rangers is for an 07-08 Ranger. But I guess that does not matter because his works on my truck.

So it looks like I will be hooking up the scanner and checking the short/long fuel trim, MAF, O2, IAT sensor and the works. Can someone explain to me the difference between short and long fuel trim to me. Will they both be a product of AFR such as 14.7 @ idle to 13.x or 12.x off idle and or at WOT? wtroger, you mention the MAF will be in lbs/hr...shouldnt I be looking at MAF voltage as well to make sure it is not pegging the voltage (5v is the max, but technically the stock tune shouldnt be anywhere near 5v IIRC) or not possibly not getting enough voltage?

Lastly, considering the truck has had this problem for a good 2 weeks again since resurfacing wouldnt that be plenty of time for a sensor(s) that is out of range to throw a code? As I have mentioned before there has never been a CEL and not a single code has ever been thrown in the 5+ times I have run a code scanner on it.

Thanks for the help, hopefully it is something simple so I can get back to driving the truck normally without fear of damaging anything with detonation.