Pinging Problem

[willbrooks2]

hey guys, i have a 95 mustang gt. The engine pings at high rpms, but only once the engine warms up. I was thinking maybe it is the egr valve or the fuel pump.The fuel pump is noisy.What do you guys think. I also have the timing advanced to 14*, i run 91 octane. The engine pinged even before i advanced the timing so i dont think that is it.

Thanks

 

[HISSIN50]

Have you pulled the trouble codes? Do you have a FP gauge that you can safely monitor?

There are about 10 things that can cause higher RPM pinging but more info is needed (does it happen under high PRM/high load, just high RPM, etc etc).

Good luck.

 

[harrisonfiveo]

mine pinged over 4k no matter what...after changing the timing chain it stopped (160,000 miles)

 

[95BLKGT5.0]

Clean your MAF real good.
If you have a K&N filter clean and re oil your air filter.
I had the same problem and went through everything.

I replaced
Fuel pressure reg
fuel pump 190
ACT
ECT
Plugs
T-stat
Ran 10% timing with 91 oct.
Cleaned injectors
I did everything and it still pinged

I took apart the MAF and did a real good cleaning job and thats what worked for me.
So before you go replacing anything CLEAN YOUR MAF

 

[SeventyMach1]

That's usually the problem.





However .... my car is pinging at high RPM/high load right now & I have no idea what is causing it. I hate to hijack ..... but JT, do you have any suggestions for me as well? I'm going to look into the EGR crap & see if the problem is there ......

 

[HISSIN50]

Justin, I find that I have to tinker with a few things to find the cause for high load/high RPM leanness. I know you have done the usual fuel filter and making sure the pump is up to par under those high demand times.......... After that, it gets kinda grey (I hate MAF since it is almost like once you rule out everything else, it's what's left. I dont know great tests for them if one cant DL).

Fuel is where I start though normally. Ill think on it a bit.......

 

[mo_dingo]

Get your timing back down to 10* and see if it does it on 91 octane still. Then follow the other suggestions above, cleaning the MAF first.
Scott

 

[nm92131]

I am having the same problem with pinging under WOT at about 4500 rpm when the engine is warm. Does anyone know if the 94 5.0 GT's have an ACT sensor? I can't see it anywhere in my shop manual, it only shows the IAT,ECT and TPS. If mine does have one, where woud it be located? NAPA does show a part number for an ACT, but they aren't sure if it is for my year or not. Maybe it has another name?

Any help would be appreciated!!

 

[SeventyMach1]

I am having the same problem with pinging under WOT at about 4500 rpm when the engine is warm. Does anyone know if the 94 5.0 GT's have an ACT sensor? I can't see it anywhere in my shop manual, it only shows the IAT,ECT and TPS. If mine does have one, where woud it be located? NAPA does show a part number for an ACT, but they aren't sure if it is for my year or not. Maybe it has another name?

Any help would be appreciated!!

ACT sensor = same thing as IAT sensor. It's located in the tubing / duct for the intake (between TB & air filter).

 

[94gtstang50]

I heard that this is a common problem with the 94-95 SN's, mine used to ping too at 4300+, after a few bolton's it stopped mysteriously, I think my car might be running rich though.

 

[ninety15.0]

My buddy had this problem all the time with his SN....it was the MAF. He put a 90mm lightning on there, (blower at the same time) but never had issues again. I guess the stock Sn MAF's are prone to this problem. Something to due with the way they are mapped. good luck

 

[ninety15.0]

ACT = Air Charge Temp i believe

 

[nm92131]

Thanks for all the info! You guys are the s***!

Justin confirmed what I was thinking too.

 

[DoctorB712]

I dont want to pretend I know much, but IAT= Idle air and it is next to the TPS sensor on the TB. ACT=air temperature sensor and that is located after the MAF before the TB.

Back to the pinging... I had exactly the same problem only when warm too. I changed everything (all sensors and I mean all of them), changed water pump, rad, fuel pump... etc. No change. Also put timing back to 10 from 14.

The point is that I cleaned my MAF and the pinging decreased but did not go away. Now I run 94 octane and I get a slight ping? Dont know why. I am changing the MAF when my car comes out of storage... I hope it helps. However, I did read that the problem might be in our EEC, that the fuel tables are not great.... I think 94-95 cobras dont have this pinging issue... however I could not tell you why that is.

Hope it helps

 

[Chythar]

I dont want to pretend I know much, but IAT= Idle air and it is next to the TPS sensor on the TB. ACT=air temperature sensor and that is located after the MAF before the TB.

You're comfusing the IAC (Idle Air Control) and IAT (Intake Air Temperature) sensors. The IAC is on the throttle body, and keeps your engine running when you're at a stop. The IAT on our cars is called the ACT (Air Charge Temperature) It's the same sensor, just a different name.

 

[SeventyMach1]

I dont want to pretend I know much, but IAT= Idle air and it is next to the TPS sensor on the TB. ACT=air temperature sensor and that is located after the MAF before the TB.

I'd like to tactfully say ... this is wrong. The part you're referring to (beside the TB) is NOT the IAT sensor. That is the IAC valve (idle air control).


And as I stated previously, the IAT sensor (intake air temperature) is the SAME thing as an ACT sensor (air charge temperature I think). And it is located in the tubing. The term "ACT" is mostly used by the Fox body guys .... and "IAT" is the term used by most SN95 people. Hope that clears that up.

 

[SeventyMach1]

Dang it! Chythar beat me to it!

 

[Zero Signal]

After looking into this a ton and lots of datalogging, trying to figure it out. . . we simply have a bad tune from Ford. I did everything to prevent pinging and no matter what I did, it would come back. The only real fix for it on my car when it was stock was to change the MAF curve via tuning device. The thing just always ran lean.

On another note, when I tore the motor apart (115k miles IIRC), there was a crap load of carbon built up on the pistons. I got it all off, but it may have contributed. But the burnt, white exhuast valves indicated a lean condition.

 

[SeventyMach1]

John ...... I always kinda believed this myself.

I also believe the shape of the combustion chambers on factory heads has a little to do with it.

 

[mo_dingo]

After looking into this a ton and lots of datalogging, trying to figure it out. . . we simply have a bad tune from Ford. I did everything to prevent pinging and no matter what I did, it would come back. The only real fix for it on my car when it was stock was to change the MAF curve via tuning device. The thing just always ran lean.

On another note, when I tore the motor apart (115k miles IIRC), there was a crap load of carbon built up on the pistons. I got it all off, but it may have contributed. But the burnt, white exhuast valves indicated a lean condition.

Ditto that. It took so much work to get all that carbon off.....I hated that part of the h/c/i swap.