Popping during WOT runs
Thread Starter
Launching!
Joined: Mar 2006
Posts: 290
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From: Hinesville, GA
Popping during WOT runs I am tuning with EFI Live and so far everything is going with the autove. I have most of my ve tables dialed in. On my log my main focus was on WOT runs in 3rd gear. I would come off the line in 1st shift to 2nd and about 30MPH I would shift in 3rd and go WOT. I am having the problem with popping/backfire around 3000-5000 RPMs. Last night I was driving and I was going about 40 I put in second and the same thing happened popping/backfire sound. I don't seem to have a problem during decel only going at WOT. I have been doing a little research on the forum and I was thinking about changing B3308 DFCO M6 Enable Temp to 255. Currently it is set to 50. To see if that gets rid of the popping that I am getting. Does that sound like a possible solution for the popping problem?
Thread Starter
Launching!
Joined: Mar 2006
Posts: 290
Likes: 0
From: Hinesville, GA
I went out on another test run to see if setting the DFCO to 140*c would cure the popping im getting. So I had the car in 3rd gear doing about 50 and around 3700-5000 RPM the car was popping when I went to WOT. I also have 19 degress of timing in my high octane table. I was wondering if that was my problem not having enough timing to burn off all the fuel. I was thinking of adjusting the timing to may 22-24 degress(I only have access to 92 octane). Does that sound like a bad idea, or am I just way out in left feild. Also on this last run I got no knock retard.
DFCO is for deceleration, not WOT. Probably not applicable.
Check that you do not have overgapped plugs or some other
ignition system weakness that would make for a sensitivity
to cylinder charge / pressure in firing. If you can see any
cylinder-mode misfire at the lower end of WOT RPM maybe
this could point to any single-cylinder issues of this sort.
Make sure Cat Overtemp Protection is disabled or you can
end up with gross over-enrichment which also will tend
to leave "stuff" to burn in the pipe.
Check that you do not have overgapped plugs or some other
ignition system weakness that would make for a sensitivity
to cylinder charge / pressure in firing. If you can see any
cylinder-mode misfire at the lower end of WOT RPM maybe
this could point to any single-cylinder issues of this sort.
Make sure Cat Overtemp Protection is disabled or you can
end up with gross over-enrichment which also will tend
to leave "stuff" to burn in the pipe.
if i can offer a little insight that is completely not tuning related. i was having the same problem along with a popping in any gear under high load and acceleration. ie say 5th gear, 50 mph and accelerating to pass someone in traffic. it would pop and backfire, and i could hear it in the exhaust. i had a spark plug with the porcelain cracked. so if you can replicate this popping under load in the same situation it might be worth the 30 minutes to check your plugs and wires.
Thread Starter
Launching!
Joined: Mar 2006
Posts: 290
Likes: 0
From: Hinesville, GA
I agree I will let the car cool and check the plugs. The have about 20,000 miles on them. I guess I should do the plug wires to while im at it. Jimmy I do have the Catalytic Converter Protection Enabled. Thanks for the info looks like I have to make a run to Auto Zone. If I pull them out then there getting replaced. I will post the results when I get back. Thanks for the help Jimmy and half.
Thread Starter
Launching!
Joined: Mar 2006
Posts: 290
Likes: 0
From: Hinesville, GA
I have PE set at 12.95 but on the runs I was getting 12.96 AFR. But only 19* of timing. I also just changed the plugs today. All the plugs looked like they where burning fine. I did not have a chance to see if it fixed the problem.
Last edited by WS6RED2002TA; Oct 9, 2007 at 12:37 AM.
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Thread Starter
Launching!
Joined: Mar 2006
Posts: 290
Likes: 0
From: Hinesville, GA
Updated I got on it today after changing the spark plugs and I did not hear any popping. I will try again later on today I could not stay in it like I wanted to so I could not really tell if that was the problem. The plugs I pulled out looked like they were burning fine. I guess they just had to be replaced.
Last edited by WS6RED2002TA; Oct 9, 2007 at 02:09 PM.
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Launching!
Joined: Mar 2006
Posts: 290
Likes: 0
From: Hinesville, GA
If the wire was loose or off would I not have misfires during all types of driving conditions and a little hesitation. It drove perfect in the city and cruise. But as soon as I went to WOT especially around 4,000 RPM's it would start popping. Well I am glad to say that the problem is gone. I got on it a few more time's today both in 2nd and 3rd and no more popping sounds.