Why does this thing ping?
Thread Starter
Racer
Joined: Aug 2001
Posts: 308
Likes: 0
Why does this thing ping?
Hey. I've been messing with this car for a month now and I have a problem with pinging at WOT. When I gun it, it'll be ok until about 40 MPH and then it'll start making a rapid pinging noise until I let off. I also see black smoke when it does this and get an SES light. I've put my timing back to stock 6 degrees and I have a hypertech chip (but it also pings on the stock chip). I have aftermarket throttlebody/heads/cams/intake/headers. I got it to go away for a while by adjusting my fuel pressure regulator upwards (which also dropped my quartermile time 1/2 second), but it came back after a day or two and the regulator screw was in the same position. I've also been stalling occasionally and every once in a while my engine will rev itself while idling. My idling was also less rough the few days it wasnt pinging. This has got to be fuel related, but where should I start? :confused:
Le Mans Master
Joined: Oct 1999
Posts: 9,713
Likes: 3
From: Sachse Texas
Cruise-In I Veteran
Cruise-In II Veteran
Re: Why does this thing ping? (1BadC4)
You don't know what your compression is? So realistically you could be running 13:1 and you would not know it? You may need race gas to run it without pinging if it is above 11-11.5:1 compression. You really should either figure out what the compression of the motor is or ask who built it.
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: Why does this thing ping? (1BadC4)
Check the EGR valve. It maybe clogged with carbon. Check the fuel pressure and check the injectors. Replace the fuel filter if its got more than 25K miles on it or its over two years old. Check the exhuast and see if the cat is plugged. The MAF and its relays are suspect too.
Did the car run okay with the mods before these problems started ?
Did the car run okay with the mods before these problems started ?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Why does this thing ping? (AquaMetallic94LT1)
I am suspicious of the knock sensor or ECS module if you can hear ping. It's supposed to retard spark when the ECM module reports knocks to the ECM. Hook up a scan tool to see if the ECM is registering knock counts. If not the knock sensor is the cheapest to replace. If the ECS module is bad, upgrade it per the C4 Tech Note or the # on my site.
If the EGR is not working you should get a code 32 once you drive for a short while above 2,000rpm.
If the EGR is not working you should get a code 32 once you drive for a short while above 2,000rpm.
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Advanced
Joined: Sep 2001
Posts: 87
Likes: 0
From: Baytown Texas
Re: Why does this thing ping? (65Z01)
My '85 did the same thing, but ONLY when the coolant temp was above 194. I replaced the knock sensor, ESC module, cap, rotor, EST module, wires, and performed all the book tests. Turned out to be a bad wire connection on the knock sensor itself. I didn't realize at the time that the ECM performs a function check of the ESC system at/near WOT past 194 degrees, so my detonation was a product of the ECM advancing the timing...getting no feedback....and setting the code "43".
Instructor
Joined: Sep 2000
Posts: 188
Likes: 0
From: Fort Collins, CO USA
Re: (1BadC4)
If the knock sensor and ESC check out OK there is something else you can try. GM makes a product called TOP engine cleaner. It will remove the carbon from the combustion chamber and valves. Has been known to reduce or eliminate some cases of "ping". As stated earlier, higher octane may be needed too. Good Luck. bf