richracing Posted March 14, 2011 Share Posted March 14, 2011 OK, here's the low down. I bought my s30 w/ L28e NA a couple months ago, P.O. said it was rebuilt, (which i believe since it doesn't leak at all) supposedly the head had a 3 angle valve job and aftermarket cam, but he couldn't tell me what brand or any specs. I do believe that it has a cam just by the sound of it, and it performs well on top end. it also has what looks like aftermarket injectors or maybe they are from another vehicle, but they definitely look bigger than stock. The car ran like **** until I bought a FPR and wideband. I tuned the FPR to 55 psi which put idle AFR at 14.8, but at WOT it goes as rich as 10.9! What could be done about this? I'm thinking about throwing a factory L28 turbo setup on it and adjust the fuel to match, or should I buy Megasquirt and tune for that cam? Another question is how do I find out what cam is in my L28? Thanks for any advise! Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted March 14, 2011 Share Posted March 14, 2011 (edited) I'm no stock EFI expert, but I wouldn't go above stock fuel pressure levels. The super richness on WOT especially supports that. What I think you need to do is adjust your AFM at idle. Get it to a proper AFR using your wideband, then (at stock fuel pressure) do a WOT run and make sure it doesn't go so rich at the top end. Edited March 14, 2011 by TrumpetRhapsody Quote Link to comment Share on other sites More sharing options...
NewZed Posted March 14, 2011 Share Posted March 14, 2011 I would read this thread before doing too much else - http://forums.hybridz.org/index.php/topic/95316-braaps-l6-efi-induction-advice-and-tips/ 56 psi with bigger injectors doesn't fit. That would give a LOT more fuel over stock since the ECU just controls open time of the injectors. Double whammy on fuel enrichment. ~ 36 psi is the stock setting with stock injectors. Your AFM has a screw for adjusting idle air volume, to lean out or richen the idle mixture. It's on the side under a rubber plug. And the ECU adds fuel when the TPS is at the idle setting. Idle mixture is essentially separate from everything else, so probably shouldn't be used for tuning for driving. Quote Link to comment Share on other sites More sharing options...
richracing Posted March 14, 2011 Author Share Posted March 14, 2011 Thanks, my next step was to adjust the afm and see if that helps. Im just currious as to why the P.O. went through all the trouble to add so much more fuel. To compensate for the cam maybe? Or maybe he is just a moron? Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted March 14, 2011 Share Posted March 14, 2011 I thought YOU bought and adjusted the FPR? That would be the reason it's so rich, excess fuel pressure. The cam would be likely to need a bit of extra fuel to compensate for the extra air, but not THAT much more Quote Link to comment Share on other sites More sharing options...
richracing Posted March 14, 2011 Author Share Posted March 14, 2011 oh, i forgot to mention the reason I bought and adjusted the FPR is because the PO had blocked off the return on the fuel rail, and the fuel pressure was at 80-90 psi i put a factory fpr from my 280zx on it and got the fuel psi to 34'ish, then it ran really lean, (didnt have my wideband at that time, but the plugs were covered in white nastyness and didnt run so great) When I got my Fuel Lab FPR and wideband in the mail and installed, I adjusted the fuel psi until i got 14.5 - 15.0 afr at idle. Quote Link to comment Share on other sites More sharing options...
boardkid280z Posted March 15, 2011 Share Posted March 15, 2011 55 psi is still pretty high. I'm not sure what the AFR is supposed to be at idle, but there's a good chance it should be more lean than 14.5-15.0. If it ran lean at 34psi, you probably don't have bigger injectors. The stock fuel system is designed to run at 36psi, so that is what I would shoot for. As long as lowering the fuel pressure doesn't lean the AFR out so much that it stops running smoothly, adjust the fuel pressure: What AFRs were you seeing when you had the fuel pressure was at 34? 13.5 is about what you should shoot for at WOT on an N/A engine. Any richer than that and you're wasting fuel. Any leaner and you might be running too hot. But usually a lean or rich condition can't damage a N/A engine like it can a turbo engine. Check your TPS and make sure it is working correctly too. Quote Link to comment Share on other sites More sharing options...
19762802+2 Posted March 15, 2011 Share Posted March 15, 2011 Are you using the stock EFI system? IIRC I don't think a stock EFI can handle a Aftermarket cam. http://forums.hybridz.org/index.php/topic/95316-braaps-l6-efi-induction-advice-and-tips/page__view__findpost__p__896700 Quote Link to comment Share on other sites More sharing options...
richracing Posted March 15, 2011 Author Share Posted March 15, 2011 as far as I know, its factory EFI. which also confuses me since everything I read says you can not use an aftermarket cam with factory electronics. eh, i dont know, it drives fine but it is seriously lacking power at WOT due to the richness. Ill just DD it around until I get megasquirt and can fine tune it. Thanks alot for the links, they are very helpful. Quote Link to comment Share on other sites More sharing options...
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