i have a 91 rs 5.0 5 speed with just over 120k on it i have had no problems till it got cold out from start up till it comes up to temp its fine but as soon as it is up to temp it pings when the motor has strain sounds like when you run cheap gas in it i have changed the coolant temp sensor the plugs cap and rotor i also have ben running high test in it and also changed gas stations thinking it may be the brand im going to change the knock sensor in a day or so but any help would be awesome

 

Have you checked the base timing? Shouldnt be much more then 2-4 degrees BTDC. 0 degrees BTDC is spec. Could also be a weak fuel pump causing the motor to lean out.

 

As a certain dimented character suggested, check the timing.
What did the plugs look like when they came out ?

 

the plugs were tanish brown they looked normal to me by the way i only have the prob after it comes up to temp so no i havent checked timming because it doesnt do it when the motor is cold but i guess ill be checking that in a day or so too i also just ordered a new map sensor and i was going to also replace the o2 sensor and the egr valve i had the egr valve off and cleaned it but it looks orignal and with 120k i figured the stuff needs replacing anyway
one more thing i also failed emissions today .... but i have 6 montha to fix it

 

What were the sniffer values ?
Those readings can tell you what to fix !

 

emissions paper says i failed the hydrocarbons and carbon monoxide but i passed the oxides of nitrogen

 

High HC is unburned fuel. High CO is incomplete burning. That combined with the pinging brings me back to timing, WAY off. Need to check that.
Or a miss. Missing will cause that, if the cat is not doing its job.
A miss causes a false lean, so it runs rich. With a good cat, should just cause the cat to run REAL hot. ( I melted two before I learned )
Kinda depends how far out of spec the HC and CO was ?
Burning oil can cause all three, high HC, high CO, and pinging.

 

ok i have a timming light and am going to set it tomorrow but am unshure where it should be someone here said 2-4 btdc or 0 is inital but the sticker under the hood says 6 @2200 rpm but thats for an automatic mine is a 5 speed what should the rpms be and what should i try to set it at i have never done timmig before i have always had a friend do it but hes on vac and i wanna get this fixed asap so what should the rpms be when i do this and a guess on where the timming should be for a 5 speed car ... thanks a bunch for those who have helped me so far ..

 

Dimented said 0, and I'm inclined to believe him. ( absent evidence to the contrary )
Usually, it's set at idle, with the ESC line disconnected.
The sticker should be for THAT car ! BUT, you say that's for an auto, and yours is a 5 speed ?
Youve never done this before ? A running engine can hurt you. BADLY ! I understand your impatience, but would STRONGLY recommend you wait for your friend.
Juat a word from an old man, it's not worth hurting you, or the car !

 

i know about motors ive ben messing with them for a long while teardowns and all but just never have happened to set timming i onderstand how it works and what to do i just have never done it myself and didnt know what the setting should be for this car thanks a bunch

 

i have adjusted the timming and the pinging is gone it just feels a little lacking in the power dep.now so i guess i just need to fiddle with it a tad more thanks to all who helped me out with this ..