Sr20det instant redline on start!?!

[ca18det_boy]

Alrighty here we go. I have an S14 SR20, PFC D-Jetro, and I ran into the strangest problem today. I had just purchased one of the circuit sports fuel rails and decided to try it out. Everything came apart and went back together with no issues at all. I had my roommate prime the lines so I could check for leaks...no leaks. After I was content with my initial check I had him start the car. It instantly revved to 5k. After I yelled at him, he told me that he didn't have his foot on the gas at all. I thought he was messing with me so I took the throttle cable off of the TB and had him do it again....same issue. I reinspected all the vacuum lines going to the manifold and didn't find anything out of the ordinary except that I was leaking a bit of meth from the fitting on my cold pipe. I then took off the cold pipe and made sure that the butterfly was closed (which it was) and unplugged the TPS. I tried starting it and it continued to rev up on its own. I then plugged the TPS back in and ran the sensor check to verify voltage (I'm good there). I then removed my cold pipe and blocked the TB with a large piece of cardboard...still revs up. By me saying it "revs up" I mean its as if I have my foot planted on the gas and just let it go! I pulled the plugs and primed the line to see if I was leaking fuel into the cylinders, and I'm good there also. I then started it and let it ride till I felt comfortable with it and it was going beyond 6500 rpm before I got nervous and shut it down. I'm open to any ideas, input, information, whatever you have. The thing about it that has me confused the most is that in order to have a running engine you need fuel, air, and spark. I have removed air from the equation all together and its still screaming on engine start. I'm seriously thinking about just calling in a priest to do an exorcism before I touch it anymore.


*Forgot to add...TPS % on start is still reading 0% throttle and boost gauge is reading vacuum...its revving up that high with out going to 0 pressure yet I'm getting some pretty gnarly turbo chuff

[super240sx7185]

You sure the throttle body isnt being held open any? Throttle cable too tight or binding.

[super240sx7185]

I know you said it wasnt but thats the only thing i can think of.

[stprasinz]

Leaking injector o ring seal? or collar? or?

[ca18det_boy]

Ok so todays update.....

Replaced plenum gasket, checked vacuum lines yet again, confirmed fuel pressure. Now it will go up to 4500 then drop and repeat. Tomorrow I'm pulling the injectors to verify the O-rings are good and switch back to OEM rail.


So in short, couple hours worth of work...same symptoms.....

[stprasinz]

try pinching idle control valve hose off, or better yet pop it off and cap it. try that with all the vaccum lines, but be sure to label them before you do.

[ca18det_boy]

Already did it with the hoses and even the FPR. No change

[stprasinz]

that high of idle means its sucking air from somewhere. if you covered the throttle body with cardboard and that didn't change anything thats eliminated. if youve blocked off all the vaccumm hoses and the hose to the idle air controller thats eliminated also. That only leaves the intake gasket, and the injector seals.

[OM3GA]

Sounds like you definitely have air getting pulled in from somewhere else in the system, If it did not do this before you changed your rail make sure you have the plastic spacers between the rail and the manifold as well as that the large rubber washer gaskets for the injectors are properly seated.

[ca18det_boy]

Alright so I think I have it figured out...hopefully tomorrow after I go get a part I'll be able to let everyone know. Anyways here is what I found out.....

On the S14 the intake manifold wraps around the fuel rail. Now if you have an S14/S15 SR with a greddy intake manifold you will have these same problems. The Circuit Sports fuel rail has a tapped port in between injectors 2 and 3. In this port CS was kind enough to put a nice anodized bolt. This bolt WILL hit the 90 degree fitting on the intake manifold which will prevent intake runners 2 and 3 from sealing thus causing my issue. Tomorrow I will either shave off a thin layer of the bolt or I will find an allen key plug that I will throw in there. Once I'm able to get the clearance I need between that fitting and where CS was nice enough to throw that port I'll be back on to let people know if it works.

Dueces!

[ca18det_boy]

Just in case anyone else runs into this problem. The fix is a 3/8 countersunk plug that you can get at any auto parts store. I purchased a 4 pack of moroso plugs for $7. The bolt that is supplied with the fuel rail DOES hit the 90 degree fitting on the gen 1 greddy intake manifolds. I was able to take her out today and everything worked just as planned. Now I'm just waiting on my TB and its back off to the dyno!

[PyR0NiAk]

Nice job figuring this out.