Boosted engine runs poorly after warmed up
10-23-2014, 03:46 PM
#1
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Join Date: Oct 2014
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Boosted engine runs poorly after warmed up
Title sums it up, according to my wideband I'm running at about a 14.7 af ration before the engine warms up, car runs nice until it heats up then my af is like 15 or 16 at idle after it's up to temperature. I bought this car with the turbo setup already installed and it looks like someone swapped an engine out, I'm thinking maybe someone didn't step down the spark plugs when they swapped? Running aftermarket injectors (Not sure of the cc's but they are orange if that helps), Intercooled Turbo, AEM FIC, Wideband 02, No CEL, anywho any help would be appreciated! Running about 6-8psi, Tian Wastegate, hks BOV.
10-27-2014, 11:45 PM
#2
Might help to have someone check the tune. Plugs and injectors could also be suspect. It's always sketchy buying a car that is already boosted cuz you don't know exactly what's in it, what's been done, and how well it was done.
10-28-2014, 06:57 PM
#4
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Took a closer look at the car, it's running stock injectors, the motor has been swapped, and somewhat recently I think. A big part of the problem was a boost leak which I sealed up although now I think I have another one. I was thinking whoever swapped the motor didn't think to step down the spark plugs, I hit up dezod and they confirmed it was one of their earlier turbo kits. I live in Peoria, IL. Here is the engine http://imgur.com/L4IHtb2,6oNRdc3 Everything seems to be well done, the FIC was nicely hidden the gauges were installed nicely, exhaust and suspension seem to all be in order. I'd like to check a few things before I resort to a tuning shop, My thoughts are the following: It was a junkyard motor so I'm thinking I should check the spark plugs and see if they need to be a step or two colder, if this is the case running a dezod at 8psi how low should I go in that regard. Next step is to spend some time finding that boost leak if there still is one, I noticed the BOV can be turned by hand so I'm thinking that may be a part of the leak issue. Any thing else after that I should try? I want the tuning place to be a last resort as it's the most expensive.
10-28-2014, 07:27 PM
#6
The plugs won't cause the engine to go lean after warm up unless there really hot plugs but the previous owner should've known you go 1 step colder when going turbo. A boost leak will contribute it as more air being added to the motor and not enough fuel to compensate. Make sure the wideband is functioning correctly. Remove the wideband from the downpipe and spray brake clean on and watch the gauge.
10-28-2014, 07:30 PM
#7
The wideband should go fully rich and stay there until all the brake clean has evaporated and the wideband can't smell the chemical... if the wideband goes lean with brake clean applied to it the sensor is not good.. sorry if i miss some words I'm on my cell...
10-28-2014, 07:33 PM
#8
P.s. the the wideband will stay rich for a day if you spray it with brake clean as the bosch sensor is super sensitive so don't drench the sensor just a few lights sprays should work...
10-29-2014, 07:20 PM
#15
Darkfox hata makes a good point but 2 step colder plugs will be too low for only 8psi. 1-step colder should be optimal for 8 psi. If you buy the IRIDIUM NGK BkR7-11 NGK recommends not to gap them but at the same time the gap might be too large for low boost settings..
10-29-2014, 07:24 PM
#19
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I think a big part of the lean idle had to do with a boost leak, there was a line that connected to the fic that i could hear so I went ahead and patched that up, I just got the snap ring in for the BOV and I'm hoping that takes care of the other big leak, cause I'm pretty sure I shouldn't be able to easily turn the bov by hand