Subaru Help

kk6rgn

New Member
Joined
Nov 27, 2017
Posts
4
RDC Crypto
4
Location
Bonita CA
I recently had my subaru 2.5 turbo dohc rebuilt and added a bigger turbo & intercooler with fans and a standalone fuel pressure regulator and had it retuned . The issue, Is the car runs Perfect for 20 to 25 minutes then it starts bucking / stumbling like it is running out of fuel or over fueling. Now I have changed all 4 coils & every sensor on this motor, I have checked all my grounds, I have even wired the New fuel pump direct bypassing everything from a seperate battery. It's like clock work the car runs like a bat out of hell for 20 to 25 minutes then she starts bucking. I will let the motor cool and she runs great for 20 more minutes. I am at my witts end and don't know what to try next, Thinking about installing my gopro pointed at my fuel gauge to see what's happening when it starts acting up. I am willing to pay someone to troubleshoot my issue because I have run out of ideas .

Thanks for reading
Johnny
 

JDDurfey

Well-Known Member
Joined
Jan 12, 2013
Posts
3,752
RDC Crypto
4,837
Location
Stephenville, Texas
So you are not sure that it isn't starving for fuel? I had a pick up that did that and found out after looking at a whole bunch of things that there was a rag in the fuel tank. After running for a while it would get sucked over the fuel pick up and starve the engine.

I would get the fuel pressure gauge where you can read it while driving so you can rule that out.
 
Advertising supports this site

kk6rgn

New Member
Joined
Nov 27, 2017
Posts
4
RDC Crypto
4
Location
Bonita CA
Thanks JD , I am at lost, new motor,new intercooler,new sensors ,new coils ,new turbo,new fuel pump,and 4 weeks of trouble shooting . I need to find someone that i can pay to troubleshoot this for me because i have just about given up.
 

brad inch

Well-Known Member
Joined
May 18, 2007
Posts
649
RDC Crypto
447
Location
tujunga.ca
clean out the gas tank, but the biggest thing is make sure it has a vent and make sure its big enough.poeple sometime just use a vented cap,thats not the best way,next time it acts up stop and open the cap.then close it and try to drive it.
good luck brad
 

JDDurfey

Well-Known Member
Joined
Jan 12, 2013
Posts
3,752
RDC Crypto
4,837
Location
Stephenville, Texas
clean out the gas tank, but the biggest thing is make sure it has a vent and make sure its big enough.poeple sometime just use a vented cap,thats not the best way,next time it acts up stop and open the cap.then close it and try to drive it.
good luck brad
I forgot about fuel tank venting. That could very well be the problem too.
 

kk6rgn

New Member
Joined
Nov 27, 2017
Posts
4
RDC Crypto
4
Location
Bonita CA
Thanks guys , Keep up the ideas, I ruled the gas tank out , I pulled the tank and rinsed it out & also unscrewed the cap thinking it was getting air locked.But thanks guys, I am down to trying anything at this point, Currently i brought the car to the guy who built the motor to have a look at it and make sure one of the valves is not getting stuck .
Johnny
 

kk6rgn

New Member
Joined
Nov 27, 2017
Posts
4
RDC Crypto
4
Location
Bonita CA
Thought i would share That i found the gremlin in my motor , I tried a suggestion that someone posted on another site and sure enough it worked. I shimmed out the camshaft sensor about 1/8 of a inch with a flat washer between the case and the sensor. That did the trick, I put about 42 miles on it yesterday without one hiccup.I am not sure why this is but I am assuming that because I am running a newer style STI case that probably the new case requires a different (shorter) sensor . I spent 4 weeks troubleshooting this issue and I hope this will help someone in the future .
Johnny
 
Advertising supports this site

jon coleman

in n out.double double w cheese
Joined
Jan 17, 2019
Posts
14,174
RDC Crypto
8,939
Location
sandiego
heat expands metal, thnx for the tip👍i Do like the 'fix', the proverbial ' 10 cent washer'😀
 

dzrt performance

Well-Known Member
Joined
Jan 31, 2014
Posts
235
RDC Crypto
165
Thought i would share That i found the gremlin in my motor , I tried a suggestion that someone posted on another site and sure enough it worked. I shimmed out the camshaft sensor about 1/8 of a inch with a flat washer between the case and the sensor. That did the trick, I put about 42 miles on it yesterday without one hiccup.I am not sure why this is but I am assuming that because I am running a newer style STI case that probably the new case requires a different (shorter) sensor . I spent 4 weeks troubleshooting this issue and I hope this will help someone in the future .
Johnny
my guess would be the shimming improved the gap on the cam sensor. loose the cam sensor, its done. a good logging ecu would have made this easy to spot,.
 
Top