Pinging at light throttles?
11-20-2001, 05:05 PM
#1
Launching!
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Pinging at light throttles? Can't seem to figure out what is going on with my engine. I recently decarbed the thing really well. Changed the plugs and the oil...that all really seemed to help smooth out the idle and improve the overall driveability of the car. Still though, things are not quite right. I get pining at light throttles that seems to disappear as I give more gas and the RPMs increase but can then suddenly re-appear if I got WOT into the higher RPM range.
I recently removed my FTRA and have not yet sealed up the cut below the airbox...I am pretty sure the engine is gulping down hot air from off the radiator....IAT sensor usually reads 115-130 even on cold (~50 degree) days. Could this hot air be causing all of the pinging problems? I guess it could be equated to having air that's 50-80 degrees hotter than ambient enter the intake. Could this be the problem? Let me know what you think guys, I have really been struggling with this one for awhile and LS1.com hasn't been much help for anything lately.
-Kris
I recently removed my FTRA and have not yet sealed up the cut below the airbox...I am pretty sure the engine is gulping down hot air from off the radiator....IAT sensor usually reads 115-130 even on cold (~50 degree) days. Could this hot air be causing all of the pinging problems? I guess it could be equated to having air that's 50-80 degrees hotter than ambient enter the intake. Could this be the problem? Let me know what you think guys, I have really been struggling with this one for awhile and LS1.com hasn't been much help for anything lately.
-Kris
11-20-2001, 05:08 PM
#2
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Re: Pinging at light throttles? Perhaps try Autotapping, you could add fuel with MAF T to the base to eliminate that part throttle pinging. Or look at how much timing you have.
BTW, we have a 5 line rule for Sigs.
BTW, we have a 5 line rule for Sigs.
11-20-2001, 05:12 PM
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Launching!
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Re: Pinging at light throttles? Man, I know exactly what you mean, especially since Kalifornia just whacked another point of octane off premium fuel (92 -> 91). Sometimes, cleaning my MAF wires with aerosol brake cleaner helps reduce/eliminate pinging like you describe, but during the summer the only way I can get rid of the ping is to run 100 octane (not a cost-effective solution, obviously!).
11-20-2001, 05:13 PM
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Re: Pinging at light throttles? Doh! How am I supposed to make 5 lines out of that? Sorry. <img src="images/icons/rolleyes.gif" border="0">
AutoCrap gives nothing out of the ordinary...coolant temps could be a little lower. Tuning is done by ED Wright, he swears to me that everything is right (now that I am on my third programming).
I can't really add any fuel to the base without getting a "too rich" SES from the car. Now that I have added the 30# SVO injectors I have to lean out about 15-20% to get LTrims back to around 0/a little negative.
About my first question though...can the fact that the engine is sucking in 125 degree air cause a lot of excess pinging at lower throttles/loads? Anyone have a guess? Thanks.
-Kris
AutoCrap gives nothing out of the ordinary...coolant temps could be a little lower. Tuning is done by ED Wright, he swears to me that everything is right (now that I am on my third programming).
I can't really add any fuel to the base without getting a "too rich" SES from the car. Now that I have added the 30# SVO injectors I have to lean out about 15-20% to get LTrims back to around 0/a little negative.
About my first question though...can the fact that the engine is sucking in 125 degree air cause a lot of excess pinging at lower throttles/loads? Anyone have a guess? Thanks.
-Kris
11-20-2001, 07:26 PM
#7
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Re: Pinging at light throttles? [quote]Originally posted by 99WhiteSS:
<strong>
About my first question though...can the fact that the engine is sucking in 125 degree air cause a lot of excess pinging at lower throttles/loads? Anyone have a guess? Thanks.
-Kris</strong><hr></blockquote>
yes warmer air can do it, but the computer should know that with x air intake temp and y coolant temp, adjust Fuel z%
how much KR are you getting? anything less that 4.0 is considered normal.
Hell in the summer i got 3.9 and my car is 99% stock
<strong>
About my first question though...can the fact that the engine is sucking in 125 degree air cause a lot of excess pinging at lower throttles/loads? Anyone have a guess? Thanks.
-Kris</strong><hr></blockquote>
yes warmer air can do it, but the computer should know that with x air intake temp and y coolant temp, adjust Fuel z%
how much KR are you getting? anything less that 4.0 is considered normal.
Hell in the summer i got 3.9 and my car is 99% stock
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11-20-2001, 09:03 PM
#8
Re: Pinging at light throttles? Well I see you still have 180 stat based on your sig...maybe change to a 160 stat. What temp are your fans set to come on at? Someone did the PCV mod w/catch can and got rid of ping because the oil was being sucked in. The website that had the mod is down so I can't link it to you. Also have you thought about one of the larger SLP radiators?
WAG: (wild *** guess) EGR flow can act to reduce combustion temp at light throttle and help avoid ping. My old TBI Camaro pings when the EGR valve carbons up. Without EGR flow your combustion temp is a little higher probably at light throttle. As to cam and it's overlap being enough to offset not having an EGR maybe so for passing emissions but I don't know the the EGR by cam over lap has the same cooling effect. Someone else might speculate on this...
[quote]Originally posted by 99WhiteSS:
<strong>Doh! How am I supposed to make 5 lines out of that? Sorry. <img src="images/icons/rolleyes.gif" border="0">
</strong><hr></blockquote>
Probably by using the delete key, changing the spacing and hacking out the extra lines, like I had to in mine. However, my engine isn't as interesting as yours...
[ November 20, 2001: Message edited by: 99 Black Bird T/A ]
[ November 20, 2001: Message edited by: 99 Black Bird T/A ]</p>
WAG: (wild *** guess) EGR flow can act to reduce combustion temp at light throttle and help avoid ping. My old TBI Camaro pings when the EGR valve carbons up. Without EGR flow your combustion temp is a little higher probably at light throttle. As to cam and it's overlap being enough to offset not having an EGR maybe so for passing emissions but I don't know the the EGR by cam over lap has the same cooling effect. Someone else might speculate on this...
[quote]Originally posted by 99WhiteSS:
<strong>Doh! How am I supposed to make 5 lines out of that? Sorry. <img src="images/icons/rolleyes.gif" border="0">
</strong><hr></blockquote>
Probably by using the delete key, changing the spacing and hacking out the extra lines, like I had to in mine. However, my engine isn't as interesting as yours...
[ November 20, 2001: Message edited by: 99 Black Bird T/A ]
[ November 20, 2001: Message edited by: 99 Black Bird T/A ]</p>
11-20-2001, 09:15 PM
#9
Re: Pinging at light throttles? Saw this on another thread, thought you might want to see it too...
[quote]Originally posted by Nightclaw:
<strong>This may sound goofy, but try cleaning your MAF wires. Whenever I start getting low-RPM ping, I clean the MAF wires with aerosol brake cleaner and it goes away for a little while. It may not solve your particular problem, but it doesn't hurt to try. <img src="images/icons/smile.gif" border="0"> </strong><hr></blockquote>
[quote]Originally posted by Nightclaw:
<strong>This may sound goofy, but try cleaning your MAF wires. Whenever I start getting low-RPM ping, I clean the MAF wires with aerosol brake cleaner and it goes away for a little while. It may not solve your particular problem, but it doesn't hurt to try. <img src="images/icons/smile.gif" border="0"> </strong><hr></blockquote>
11-20-2001, 10:06 PM
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Re: Pinging at light throttles? I second looking at the Knock Retard numbers in conjunction with total timing advance in order to come to "net timing."
3.9 degrees is excessive in it's own right, especially at light throttle applications.
Once again, whats really important is "Net timing."
[ November 20, 2001: Message edited by: CMNTMXR57 ]</p>
3.9 degrees is excessive in it's own right, especially at light throttle applications.
Once again, whats really important is "Net timing."
[ November 20, 2001: Message edited by: CMNTMXR57 ]</p>
11-20-2001, 10:10 PM
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Re: Pinging at light throttles? I also see you have PCM programming by Ed Wrong. This could be part of your problem.
Check to see that your EGR turns on under part throttle applications. If not, this could be responsible for some KR. He seems not to listen when he asks if you have an LS6 intake (hence no EGR) but you still have the LS1 intake and he still turns it off. <img src="images/icons/rolleyes.gif" border="0">
Check to see that your EGR turns on under part throttle applications. If not, this could be responsible for some KR. He seems not to listen when he asks if you have an LS6 intake (hence no EGR) but you still have the LS1 intake and he still turns it off. <img src="images/icons/rolleyes.gif" border="0">
11-22-2001, 02:21 PM
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Re: Pinging at light throttles? To answer your ? about the temp of the inlet air charge relationship to detonation issues, yes; A hot inlet air charge will in some cases cause pinging. ... A general rule of thumb is; for every 1degF you change your air inlet charge you'll change your exhaust temp by 3. This is the whole concept behind inner coolers, aftercoolers, and dry intake manifolds exc.
On the other hand, I'm questioning whether your IAT's are accurate. Although my airbox is stock, it too sits on top of my rad top tank. I see IAT's below ambient always while moving down the road, only while sitting idle will it climb up above ambient and never any ware near 130F.
Your car is heavily moded and little things are really going to stand out. ... Check the accuracy of your IAT, it should read ambient air temp after sitting overnight. ... IF its reading ok then get simple things like your air box straightened out.
let us know ... 1002
On the other hand, I'm questioning whether your IAT's are accurate. Although my airbox is stock, it too sits on top of my rad top tank. I see IAT's below ambient always while moving down the road, only while sitting idle will it climb up above ambient and never any ware near 130F.
Your car is heavily moded and little things are really going to stand out. ... Check the accuracy of your IAT, it should read ambient air temp after sitting overnight. ... IF its reading ok then get simple things like your air box straightened out.
let us know ... 1002
