The Gsr's modifications are as follows: AEM CAI, DC Header, EVO exhaust, Skunk2 Intake Manifold, Gude Throttle body, and CTR Intake Cam. The problem is after installing the CTR cam a week later the check engine light came on. We used the jumper wire on the Ecm and the check engine light flashed the code, which then we looked up and found that the car is running too lean. Now we are thinking of getting a fuel pressure regulator and a gauge to fix this problem. My question is, Is the fuel pressure regulator going to fix this problem? and do any of you guys have any recommended settings for the fuel pressure regulator? My brother is kind of short on cash right now, so we are just trying to do this on our own, so he can at least drive his car without worrying about running too lean.

 

ttt

 

i just got an AEM fuel rail and regulator and put it on my 94 LS which has AEM cai, dc sports header and exhaust, the literature says to tune between 40-47psi fuel pressure with the vacum line disconnected so I tuned it to 45psi and I can definitly feel a difference in power. the car pulls noticably harder from 3500rpm all the way to redline. i dont know if this is the perfect setting but it sure feels better. I dont know what fuel pressure to reckomend for your car so i say definitly get the regulator and go to a dyno, start at stock pressure and go up from there. i imagine with all the mods you have done to increase the air coming in when you do get the fuel to match your performance gains will be even more abundant then mine. good luck


[Modified by kingrobby, 10:51 AM 7/28/2002]

 

stock pressure should be fine

i would look over ur install and make sure everything is OK

 

Do you have cam gears on your car and a Skunk2 intake manifold? My brother has AEM cam gears and they are set at +2 Intake and -1 Exhaust and he has the Skunk2 intake manifold with Gude throttle body. Never had any problem with runnin lean until we installed the CTR cam. I think that with the skunk2 intake manifold and the throttle body he is getting alot more air flow than other Gsr's. Not to mention adding a little more aggressive cam on top of that. I think with all these parts he is getting alot of air and no fuel. What do you guys think?

 

No, i only have the engine mods i have listed. Lots of people will say to leave your fuel pressure the same as stock but it has been dyno proven from various magazines and tuners that after adding performance parts that increase airflow you need to increase fuel flow in order to get an even bigger power gain. When you add a header, or intake, or exhaust you're only making the engine more efficient with airflow, which in turn leans out the air/fuel ratio, which gives you some more power, but if you add more fuel to take advantage of the more efficient airflow power gains will increase even more.

 

 

maybe for turbo applications yes u must have air/fuel to match but just adding
CTR cam should not be causing any probs.
our cars run rich from the factory so there is plenty of fuel there anyways.
what is ur fuel pressure at?
u didnt retard ur exhaust cam by accident?

 

The exhaust cam gear is retarded 1 degree. With all the stuff that he has on his car I wouldn't be suprised if he was running a little lean. He does have the Skunk2 intake manifold.

 

When you get some $$$ get a FPR and a VAFC then take it to the dyno and pay the money to have it tuned...the car will drive like a completely different vehicle...it will be some of the best $$ you spend.

Come to think of it...this combo would only be a couple of hundred $$$ less than a Hondata stage 2...I'd save up and invest in it if I were you. http://www.dynospotracing.com is one of the local reputable shops...it's the only shop that I'd trust.


[Modified by Austin, 12:08 PM 7/29/2002]

 

Does anybody know what the fuel pressure is on a stock Gsr? And with the modifications my brother has on his Gsr what do you think would be a good pressure to go with until he gets it dynoed?

 

If you go to a reputable dyno they will be able to make some recommendations of where to have the pressure at...just don't go to RPM in Rohnert Park.

Austin

 

FP for GSR is 39 to 46psi w/ vacuum attached
and 48-55 psi disconnected

some ITR owners just set their fuel pressure at 50 psi and tune from there.
use the VAFC to subtract or add fuel as needed according to a/f ratio's while on the dyno. i know my FP is at 48 psi currently and it was at 44-46 psi when tuning and i had to take out alot of fuel when on the dyno w/ the VAFC.

i had no CEL's after ITR cams and skunk2 mani install also

 

Did you get any CEL's before you got the fuel pressure regulator? Has anybody had any CEL's after the installation of CTR or ITR cams?

 

nope never got a CEL.
i put the FPR on along with the skunk2 mani

 

So you never ran your car with just the Itr cams and the Skunk2 manifold? You put the FPR on the same time you put the skunk2 manifold on?

 

You said your fuel pressure is at 48 psi currently is that with the vaccum hose connected or disconnected? And are you still running 48 psi with the Itr cams?