Engine Pinging

[94expo]

Im getting a Pinging sound when accelerating. And Only after engine is warmed up. When I first start, it runs great then after about a mile It will start Pinging or Valve chatter Duing Acceleration. Iv replaced Both O2 sensors and Fuel pressure Reglator and Catalytic converter. There are no codes. Help!

 

[hamexplorer]

Pinging

I have the same problem. I had to switch to hi-test gas.

 

[Rhett]

Do a search on ping here and you will find tons of information about the ping.

You could also have a dirty MAF. You might have carbon build up, which the 4.0 OHV motors are prone to get. Do a search for a product called "Seafoam".

 

[94expo]

I Cleaned the MAF. I thought Carbon build up would cause Pinging al the time. This thing runs great when You first run. For the firdt mile or 2 it runs like new. then the Pinging strart to increase slowly.

 

[94expo]

I was leaning toward the EGR system. How can i test it hot.

 

[Opera House]

Did it run any diferently after the FPR?

After I replaced my FPR, which was definitely bad, the engine still had problems for 200 miles. Then I disconnected the battery to reset the computer. It ran fine after that. Thought sure it would have "learned" in that time.

I would check to see that the vacuum line at the regulator pulls a really good vacuum. If the line going to it has a leak, The mixture at idle would be overly rich which the computer would correct for. Then on acceleration, the mixture would be lean because the regulator wouldn't boost the fuel pressure.

 

[94expo]

Yesterday I cleared my codes/ computer and today I got a new code. 327. EGR valve position (EVP) sensor. Pressure feedback EGR (PFE) sensor or EGR pressure transducer (EPT) signal voltage too low.

 

[DaHeinah]

94Expo, I had the exact same problem and lost almost all my hair trying to figure it out...Ok so lied about the hair part . I installed an Apten chip and put in premium gas and...STILL PINGED!!! AFter cursing for about 5 minutes straight, I concluded that the problem was not resolved. So, I purchase a KKM kit with a Granatelli cold air MAF..and no more ping. Seriously, my brother's '92 X had the same pinging problem and the granatelli MAF fixed the problem and definitely enhanced performance. Just give it a try, here is the link: www.Summitracing.com
BTW- Be sure to specify the cold-air version as it is definitely worth it. Hope this helps.
Greg

 

[94expo]

I figered since it hasn't done this before there is a problem somewhere. before I go with the Mods id like to make it run as good as posible stock. then add the go fast stuff over a good engine. I think its somewhere in the EGR system. since I got the EGR codes. The EGR lowers the Temperture of the combustion by recirulating a small amout of exhaust back into the intake. I was trying to test some of the units out on the system but I need to find a good wire diagram 1st. A good guess with out a voltage check I think the problem could be in the DPFE. its $50 so Id like to test befoe a change out.

 

[Apten]

a lot of 4.0 OHV's get a leak in the intake gasket which causes pinging. That may be a place to check.

Brian

 

[94expo]

Ya I seen the problems on here with the intakes but it doesn't always do it and plus im getting the EGR code. And EGR problems will cause pinging.

 

[Rhett]

It could well be your EGR like you said.

The reason it won't ping when it is warming up is because the computer is operating the engine rich at that time. The PCM runs it rich so that the engine warms up faster--and the sooner the engine warms up, the faster the cats and O2s light off--and when this happens your vehicles emissions will reduce.

As soon as the cats and O2s reach their operating temps, the computer will lean out the mixture. The PCM will lean the mix according the inputs from sensors (like the O2 sensor, MAF, etc.). If you've got carbon buildup in the combustion chamber, this effectively raises the compression ratio of the engine because there's less space in there (it's taken up by carbon deposits). The PCM can't detect the smaller amount of combustion space, and so it will calculate the air/fuel ratio based on what cylinder area you should have. When "should havE" and "actual" don't match up thats when you can get ping problems. When you raise the compression ratio, you have to run higher and higher octane gas to prevent pinging. So carbon (or other things like bad EGR or dirty MAF) throws the whole system out of balance. So irregardless of what's causing your pinging, the reason is the PCM is effectively over-leaning. This doesnt necessarily mean the PCM is bad, it means that it's not getting all of the information it needs to calculate the best air/fuel ratio. Computer controlled engines are tuned so closely out of the factory, they are very finicky--so if 1 thing is out of kilter it can do it.

 

[LStoudenmire]

94Expo, This thread may help. I had a similar problem.
Dead Link Removed

 

[94expo]

Thanks for the link LStoudenmire. I was kinda leaning in the direction of the PFE but never seen anyone having problems with them. your link indicates otherwise. I think ill change it out later this week. I did spray some carb cleaner up in the Vacum port on it and it seamed to have helped. Ill let you know how this one comes out. I guess 1st I need to get one on order.

 

[LStoudenmire]

You shouldnt need to order it. The local parts store (Advance Auto, in my case) had them in stock. Good Luck!

 

[94expo]

Everyone here with the exception of ford dealers needs 2 days for delivery. and for want double the cost. So ill wait the 2 days.

 

[hamexplorer]

where is the temperature sensor located?

 

[TPLYNCH]

Search and you would have found... http://www.explorerforum.com/forums...8230&highlight=temperature+sensor+AND+located

 

[94expo]

I tryed everywhere to find seafoam. I was going to do a good cleaning but could not find it so I Just got done running a full tank of gas with Slick 50® Engine Treatment For High Mileage Vehicles. That was the only other thing I could find to clean combustion chamber area out. Well Its running Like a hungery monkey after a fresh pound of banana's. Hope it keeps it up. I need to fine the seafoam stuff still. I need to turn it into a baboon.

 

[Rhett]

I put seafoam in my gas and it hasn't stopped the ping with 87 octane.

I guess I need to try it thru one of the vac lines. Or else carbon isn't my problem.