backfire popping under boost
Jan 23, 2011, 02:52 PM
#1
backfire popping under boost
Hey guys im having a problem with my newly purchased evo. Bought the car a few weeks ago and the car ran great, somtimes it would hit fuel cut under boost at WOT but I figured that was caused by the cold temps and was gonna get it retuned. Well when I was changing the oil I noticed antifreeze under the car checked everthing and cleaned it off and came to the conclusion the car was pushing antifreeze out of the overflow tank when under boost cause by the head gasket.
So this weekend I removed the head and put a new head gasket in with new arp head studs. I also replaced the water pump, timing belt, balance shaft belt, idlers, and tensioners. I also added a few parts an ebay o2 housing, new autolite iradium spark plugs, evo 9 bov, and a vibrant air filter from map performance. The car also already had a few mods done to it such as a 3 inch tbe, evo 9 turbo, AMS fmic, licp, hks 272 camshafts, 255 walbro fuel pump, and a street tune.
Now with my problem after finishing everything up the car starts and runs great and drives great. when i went for a drive I can boost up to 5-10 lbs then the car acts like its hitting fuel cut really bad and pops and backfires is this caused by the tune being off so far? Or am I forgetting somthing and hooked somthing up wrong.
I also notice with the evo 9 bov is much louder then the evo 8 bov and flutters alot under boost is that normal? im just baffled right now so im looking for answeres. if its the tune great I can get it retuned and planned on it soon anyways but I dont wanna drive the car 500 miles to get it tuned with somthing being wrong with it or getting there and they cant tune it cause of the problem. Any help with be much appreciated.
Thank you
So this weekend I removed the head and put a new head gasket in with new arp head studs. I also replaced the water pump, timing belt, balance shaft belt, idlers, and tensioners. I also added a few parts an ebay o2 housing, new autolite iradium spark plugs, evo 9 bov, and a vibrant air filter from map performance. The car also already had a few mods done to it such as a 3 inch tbe, evo 9 turbo, AMS fmic, licp, hks 272 camshafts, 255 walbro fuel pump, and a street tune.
Now with my problem after finishing everything up the car starts and runs great and drives great. when i went for a drive I can boost up to 5-10 lbs then the car acts like its hitting fuel cut really bad and pops and backfires is this caused by the tune being off so far? Or am I forgetting somthing and hooked somthing up wrong.
I also notice with the evo 9 bov is much louder then the evo 8 bov and flutters alot under boost is that normal? im just baffled right now so im looking for answeres. if its the tune great I can get it retuned and planned on it soon anyways but I dont wanna drive the car 500 miles to get it tuned with somthing being wrong with it or getting there and they cant tune it cause of the problem. Any help with be much appreciated.
Thank you
Last edited by iluvmydsm; Jan 23, 2011 at 02:55 PM.
Jan 23, 2011, 02:58 PM
#2
Newbie
iTrader: (6)
Join Date: Nov 2009
Location: apple city
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
Hey guys im having a problem with my newly purchased evo. Bought the car a few weeks ago and the car ran great, somtimes it would hit fuel cut under boost at WOT but I figured that was caused by the cold temps and was gonna get it retuned. Well when I was changing the oil I noticed antifreeze under the car checked everthing and cleaned it off and came to the conclusion the car was pushing antifreeze out of the overflow tank when under boost cause by the head gasket.
So this weekend I removed the head and put a new head gasket in with new arp head studs. I also replaced the water pump, timing belt, balance shaft belt, idlers, and tensioners. I also added a few parts an ebay o2 housing, new autolite iradium spark plugs, evo 9 bov, and a vibrant air filter from map performance. The car also already had a few mods done to it such as a 3 inch tbe, evo 9 turbo, AMS fmic, licp, hks 272 camshafts, 255 walbro fuel pump, and a street tune.
Now with my problem after finishing everything up the car starts and runs great and drives great. when i went for a drive I can boost up to 5-10 lbs then the car acts like its hitting fuel cut really bad and pops and backfires is this caused by the tune being off so far? Or am I forgetting somthing and hooked somthing up wrong.
I also notice with the evo 9 bov is much louder then the evo 8 bov and flutters alot under boost is that normal? im just baffled right now so im looking for answeres. if its the tune great I can get it retuned and planned on it soon anyways but I dont wanna drive the car 500 miles to get it tuned with somthing being wrong with it or getting there and they cant tune it cause of the problem. Any help with be much appreciated.
Thank you
So this weekend I removed the head and put a new head gasket in with new arp head studs. I also replaced the water pump, timing belt, balance shaft belt, idlers, and tensioners. I also added a few parts an ebay o2 housing, new autolite iradium spark plugs, evo 9 bov, and a vibrant air filter from map performance. The car also already had a few mods done to it such as a 3 inch tbe, evo 9 turbo, AMS fmic, licp, hks 272 camshafts, 255 walbro fuel pump, and a street tune.
Now with my problem after finishing everything up the car starts and runs great and drives great. when i went for a drive I can boost up to 5-10 lbs then the car acts like its hitting fuel cut really bad and pops and backfires is this caused by the tune being off so far? Or am I forgetting somthing and hooked somthing up wrong.
I also notice with the evo 9 bov is much louder then the evo 8 bov and flutters alot under boost is that normal? im just baffled right now so im looking for answeres. if its the tune great I can get it retuned and planned on it soon anyways but I dont wanna drive the car 500 miles to get it tuned with somthing being wrong with it or getting there and they cant tune it cause of the problem. Any help with be much appreciated.
Thank you
Jan 23, 2011, 03:21 PM
#5
The cam timing is right on checked it about 5 times before I put the car back together
also did a boost leak test everything seemed to be fine there
the car was running ngk bpr7es in it before but they looked pretty crappy so i got these oem specification autolite irdaiums but ill go get a set and try it in a few minutes before oreilly closes
also did a boost leak test everything seemed to be fine there
the car was running ngk bpr7es in it before but they looked pretty crappy so i got these oem specification autolite irdaiums but ill go get a set and try it in a few minutes before oreilly closes
Trending Topics
Jan 23, 2011, 05:00 PM
#8
Evolving Member
iTrader: (5)
Join Date: Sep 2009
Location: Hickory, NC
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Another +1 on the NGK plugs, I made the mistake of running autolite plugs, the ignition sounded like it was breaking up like crazy under boost. Put on NGK Iridiums and problem immediately went away.
Jan 23, 2011, 05:53 PM
#12
Evolving Member
iTrader: (5)
Join Date: Sep 2009
Location: Hickory, NC
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
In case you're wondering..
BPR7EIX = Stock
BR7EIX = 1/2 step colder
BPR8EIX = 1 step colder.
Jan 23, 2011, 07:41 PM
#14
Former Sponsor
iTrader: (19)
Join Date: Jul 2010
Location: NC
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
The cam timing is right on checked it about 5 times before I put the car back together
also did a boost leak test everything seemed to be fine there
the car was running ngk bpr7es in it before but they looked pretty crappy so i got these oem specification autolite irdaiums but ill go get a set and try it in a few minutes before oreilly closes
also did a boost leak test everything seemed to be fine there
the car was running ngk bpr7es in it before but they looked pretty crappy so i got these oem specification autolite irdaiums but ill go get a set and try it in a few minutes before oreilly closes
Josh
Jan 23, 2011, 08:05 PM
#15
Evolving Member
iTrader: (9)
Join Date: Apr 2008
Location: Cincinnati, Ohio
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
This is funny because i just changed my plugs to BR8ES plugs which is what my tunner put in the car. I have the exact same mods as you except all buschur parts and buschur tune with an 03 evo 8 turbo.
I would recommend going with the BR8ES plugs and gapped 0.024". I assume you meant 0.03" before = ) Not 0.3"
Good luck and let us know what happens
I would recommend going with the BR8ES plugs and gapped 0.024". I assume you meant 0.03" before = ) Not 0.3"
Good luck and let us know what happens