5.0HOBOMB

I've tried all I can think of, but my engine still pings under load and hard acceleration. I have a 95 mustang gt 5.0 liter engine. I got computer codes, and it gave me two codes (egr valve not openening, transmission speed checker malfunctioning) so I changed my EGR valve, it still pings. I checked my timing. The timing was lagged, so I put it back to 10 degrees, and engine still pings. I tried using 91 octane fuel but engine still pings. I cleaned the MAF, and changed spark pluges, and wiring and engine still pings. This is driving me nuts!!!!! Does anyone have any suggestions to what may be the problem?????

mattdel

wicked high miles? i'd say Seafoam it. carbon buildup on your valves is raising the combustion chamber temperature by effectively raising your compression ratio a bit..

happened to my dad's Durango. half a can of seafoam through a vacuum source, problem solved.

samseed101

If you're pinging, advancing the timing even more isn't going to help any. I'm not sure why it would have ben retarded to whatever it was, but perhaps the previous owner knew of the pinging issue and did it.

What I would do is get it somewhere where you can check the A/F ratio with a wideband and see if you're running lean.

Do you have a chip installed? As dumb as it may sound, perhaps someone added some timing leectronically by changing the global spark advance in your scalars. That's how I change my timing (instead of turning the distrubutor.)

gspfunk

Also, make sure the balancer hasn't spun and isn't loose/wobbling. That can lead to incorrect timing even though it looks to be accurate.

EVO32

i noticed that my 94 gt with 92K miles pings but with premium fuel it does not ping. the spark plugs look like they are running hot from the wear marks and when i did a timing test it only advanced like 1/4-1/2 an inch, does that sound right? whats this seafoam stuff? do you think it could be worth a try and what else should i check on my car to see why it pings?

mattdel

http://www.seafoamsales.com/motorTuneUp.htm

available at autozone

Twisted

Does your car burn any oil? Either way, I'd either run Seafoam or Techron. I ran two Techron treatments in one month--the big bottles--and my pinging issue has all but gone away. I also ran the bitch ragged while the Techron was running through.

I'd also check for vacuum leaks at hose connections and manifold gaskets. There could be something else causing the pinging, but I'd try the easy remedies first. Good luck.

89stanglx

I would set the number one cylinder at TDC on the compression stroke, verify the rotor is pointing to the number one stud on the distributor. Verify firing order again, and pull the spout connector and verify timing is at 10 deg. If you still get pinging maybedecrease 2 degrees at a time. also see what your fuel pressure is at.
Good luck!

PRO50SC

Ok so you replaced the egr valve. Did you properly test the old one? Is the system functioning though. Did you check that first? Do you know how to test it? Could be a bad egr positioning sensor as well.

5.0HOBOMB

Wow, many suggestions, but that is good!!! I'll do the easy and cheap ones first, then I'll go high tech I guess, but there is one problem, I'm not all that good at engines, so I'll see what I can do by myself first. The old EGR valve did open,but not very easily. I pussed it open and close with a screwdriver, it was'nt to hard for me, but it sill had some pretty bad friction. Many people have told me it could be a vacuum leak, so That is my next check, but what exactly are the vaccum hoses. Are these all networked within the emissions system??? The car has 112k miles, so it's not that bad I guess. funny think is that the pinging tends to happen more in summer than in winter, so that adds another variable to the equation. How can I tell if the positioning sensor is not working as well, becuase I did think of that before. So do you guys think changing gaskets may fix the problem. Changing gaskets would be my last resource, but for now, positioning sensor, vaccuum hoses, and chip check it is.

thanks alot for you help!!!