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View Full Version : S13 SR20det swap idling/running poorly/rich


97SerevoSX
07-12-2011, 07:10 PM
Alright, first off I have a wiring specialties harness so I assume all wiring is good to go. all connections are secured well.

Got the car running a couple days ago but it was stumbling and dying easily and I could barely get into boost it's missing out so bad.
I have a Greddy knockoff intake manifold and the teflon gasket that came with it was leaking, as there was fuel on top of the gasket.
Replaced that with the stock IM gasket, no more fuel leaking there, assume its good to go.

The car is still missing at idle really bad, I've checked everything for leaks with soapy water and can't find anything. I can rev it up to about 5500-6k if I barely push the throttle down a little as I go but then it starts breaking up and missing.

Driving it pulls pretty well with little to no miss from 2k rpms to about 3300 and then it breaks up bad up to around 4k and it just refuses to go any higher no matter how much or little throttle.

I've changed MAFs with a known good one, I changed the coils with no effect, I've gapped my plugs to .027"-.028", if I unplug the MAF it idles the same but wont rev over the 2500 limit... When I first cold started it this morning I unplugged the coolant temp sensor and it seemed to run a little better until it warmed up and then it died and wouldnt start again until I plugged it back in.
Also I set my CAS exactly how the FSM says to, lined the right most dot up, slid the CAS in and then it lined up with the left most dot perfectly.

I pulled my plugs out and replaced them with the ones that came in the engine and nothing changed, though my plugs were really black so I cleaned them off before putting them back in (when I gapped them) with no change.


I can't think of anything else right now that I've tried but since Saturday I've done nothing but search and troubleshoot with no increase in performance to speak of. Can anyone help me!?

OkiDori17
07-13-2011, 01:31 PM
i had the same problem with mine, just like you i checked everything and no answer
i ended up rewiring my grounds and checking my gaps on my plugs and it made a huge difference...dont know if that will help you but its something to at least try

97SerevoSX
07-13-2011, 06:04 PM
All of my grounds are bolted up, and its a Wiring Specialties harness.

I did find today that I have a different FPR on the fuel rail i was using so I put what I know is a stock one on and I was able to hit a little over 2.5 pounds of boost but then around 3500 it started breaking up, and at 4000 rpms it sputters really bad and wont go any further

KiLLeR2001
07-13-2011, 06:11 PM
FYI, stock gap on the SR is 0.036". Unless you are running more boost I would open up the gap a little bit. Make sure the ground for the coilpack harness is connected properly / on a clean metal surface.

97SerevoSX
07-13-2011, 06:17 PM
Ahh, I'll change the gap back.

I also replaced the coil pack harness this evening and I put the ground to the harness and the one that goes to the firewall to a bolt on the back of the head.

Other than gap, and potentially fouled plugs, I suspect the ignitor may not be firing very strong. Could still be a vacuum leak, I can hear air rushing in or around the intake manifold (my knock off GReddy) and I don't know if that's normal or not..

dsmvsep3
07-13-2011, 06:22 PM
get some brake clean and spray it around the intake mani that will let u know if u have a leak

KiLLeR2001
07-13-2011, 06:25 PM
Anytime you hear the sound of air hissing around the intake manifold, you have a leak.

97SerevoSX
07-13-2011, 06:27 PM
Right, finding it is the problem though. I've sprayed dish soap and water all over it and never found anything... Can't get to the under side of the gasket very well.

What will the brake cleaner do? bubble up, dry up really fast, what am I looking for with that?

GroundPerformance
07-13-2011, 06:33 PM
Spraying brake cleaner to areas suspected of leak will cause your idle to jump for a bit since its actually gas thats getting sucked in.

97SerevoSX
07-13-2011, 06:36 PM
Ahh alright, I'll go pick some up then tonight and see what I find out
Thanks for the advice, I assume that if there is a leak on the intake manifold gasket then the manifold itself is to blame, head was nice and flat and this is the second gasket that hasn't worked on it...

gg CXRacing intake manifold..

97SerevoSX
08-01-2011, 11:02 AM
by the way, I found out that my problem was I have low compression on one cylinder so I pulled the engine until I can get that fixed...