Surfcast23 Posted July 5, 2019 Posted July 5, 2019 I have been experiencing violent bucking combined with/followed by a loss of acceleration from about 2500 to 3000 rpm. I have seen a few older posts with this problem and wanted to know if anyone has figured out a solution?
Max Capacity Posted July 5, 2019 Posted July 5, 2019 How old are the spark plugs ? Have you done a boost/vacuum leak test ? Most likely a hose blew off a fitting. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here
Surfcast23 Posted July 5, 2019 Author Posted July 5, 2019 How old are the spark plugs ? Have you done a boost/vacuum leak test ? Most likely a hose blew off a fitting. Plugs are only a few years old. Have not done a boost/leak test. Will look for loose hoses once it cools down a bit m.
Max Capacity Posted July 5, 2019 Posted July 5, 2019 If you need a great shop, up in Sterling MA is ESP, Enhanced Street Performance. For a leak test, block/plug the black hose from the air filter box with a pint size paint can, pull the small hose off the blow off valve, give that hose a quick blast of air from a compressor, then put you thumb over the hose, listen for leaks. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here
FJuan Posted July 5, 2019 Posted July 5, 2019 Between 2,500 to 3,000 RPM is what we call the studder zone, which is common with the 4th gens. Some have fixed this with an upgraded fuel pressure regulator like an STI regulator and some have fixed it with a Tune. There are several threads on this topic. I was able to fix mine with a new LGT fuel pressure regulator and new fuel hoses to the intake manifold. Eliminating the OEM fuel connectors at the intake manifold. My wife's balls are delicious.
bigBADbenny Posted July 6, 2019 Posted July 6, 2019 My bet is avcs solenoids. Log the vvt angles with Romraider or Btssm
Surfcast23 Posted July 11, 2019 Author Posted July 11, 2019 I am also getting these CEL codes, p0345, p040, and p045 with occasional no start. Could these all be related?
system60 Posted August 2, 2019 Posted August 2, 2019 Going through same issue, car studders bad and goes lean as hell. Only happens for me under light throttle or cruising, if I give it 50% or more throttle through the same range it's fine. My tuners spent a lot of time with no real improvement. Going to be doing new plugs at next oil change. PS. It only started after I had the engine built. I had DE 850s prior and did a topfeed conversion with 1000s(e85 eventually). Opensource tune by same tuner before and after. Sent from my PH-1 using Tapatalk
system60 Posted August 27, 2019 Posted August 27, 2019 Add me to those that resolved with a new fuel pressure regulator. Ended up going with an Aeromotive and cleaning up the mess that is our feed/return setup. Sent from my PH-1 using Tapatalk
Recommended Posts
Archived
This topic is now archived and is closed to further replies.