| Go back to previous topic | | Forum name | Turbo/Nitrous Tech | | Topic subject | Plugs loading up, need some advice | | Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=28783 |
28783, Plugs loading up, need some advice Posted by 98RsT, Aug-12-02 11:24 AM
Well I am still having a problem with my plugs loading up, even after i replaced my o2 sensor. This problem is really annyoing because when i am just sitting at a stop light i get misfires, and when i jump on the throttleand as i jump right into boost, it lugs and then boosts a little, then lugs again. I am trying everthing that is comming into mind. Changed o2 (cel came on and that was the code). Change plugs like every weekend (because the 4th cyl keeps loading up really bad, and i get a cyl 4 misfire code). Adjusted the throttle body (from the factory that sucker wasn't even opening up all the way). Any one else have any ideas, or know of a performance shop near Redlands Ca where i can go to seek help, this would be greatly appreciated. Oh anyone know what fuel pressure i should be running at idle and at boost? Boosting 5 intercooled psi. Thanks for any suggestions.
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28784, RE: Plugs loading up, need some advice Posted by Dave_FL, Aug-12-02 11:49 AM
Idle fuel rpessure should be around 48-52. Boost fuel pressure at 5 psi should be around 85-90psi.
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28785, RE: Plugs loading up, need some advice Posted by fly1, Aug-12-02 01:06 PM
I have a similar problem (symptoms), but I think mine is ignition related. What is your current fuel setup--what fuel pump, injector size, FPR, fuel pressure, etc?
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28786, RE: Plugs loading up, need some advice Posted by 98RsT, Aug-12-02 02:21 PM
I am running stock injectors off of the Walbro pump and the Vortech FPR that comes in the Star kit. Currently i am running at about 60psi of idle fuel pressure, and at full boost i am hitting upwards of 110 at times. This sounded too high to me that is why i was asking. Now that i know what psi i should be running how do i get there with the Vortech FPR? (I am under the impression looking at this FPR that it isn't possible to adjust it). In which case is there an FPR out there that anyone would suggest? Thanks guys.
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28787, RE: Plugs loading up, need some advice Posted by Matt_95tgs, Aug-12-02 02:54 PM
you adjust that regulator's rise rate by putting in different calibration disks. You can order the disk kit that comes with all of the different disks from Vortech I believe for like 40 bux. If you want a completely adjustable regulator, everyone here is going to recommend the Vortech SFMU. This regulator allows you to change calibration disks to change the rise rate, adjust the static pressure by a screw on top, and bleed off excess boost to lower the WOT fuel pressure by an adjustable valve on the side.
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28788, RE: Plugs loading up, need some advice Posted by XtremeRS, Aug-12-02 02:52 PM
I believe you can buy the optional bleed valve for the FMU from Vortech. This will let you bleed off some boost pressure at the FMU , to help lower and fine tune you fuel pressures. I will suggest the Vortech SFMU. Very nice unit, and extremely versatile. 250-300 new. You can adjust idle fuel pressure with this, and no need to run the stock fuel pressure regulator.
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28789, RE: Plugs loading up, need some advice Posted by 98RsT, Aug-12-02 03:24 PM
Awsome guys thanks for the recommondation for the Vortech SFMU. However are we all on the same page thinking that the excessive fuel psi is causing my fouling plugs? I have seen people who are running a little rich and are still arn't coming close to fouling their plugs up.
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28790, RE: Plugs loading up, need some advice Posted by XtremeRS, Aug-12-02 03:36 PM
check your compression for the hell of it. Low compression in a cylinder can cause incomplete mixture burn, and foul up the plugs. 110 psi of fuel is pretty rich for 5 psi of boost. That will fould them, but not to the extent of causing misfires i would think..but i could be wrong..110 psi of fuel is enough fuel for around 8 psi...Try to get your boosted fuel pressure to around 80-85 psi at 5 pounds boost. Try and get the fuel pressure at 0 hg's at around 55 psi-60 max. But def check your compression...a bad HG will cause a missfire feel when the motors running...I guess my next question is that are ALL of your plugs fouled, or just the #4??
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28791, RE: Plugs loading up, need some advice Posted by fly1, Aug-12-02 03:41 PM
The plugs fouling all the time is pretty good indication that you're running extremely rich. The best bet is to get the S-FMU like the other guys have advised. Your fuel pressure is quite high at idle and at WOT (given your current boost level).
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28792, RE: Plugs loading up, need some advice Posted by 98RsT, Aug-14-02 04:29 AM
Thanks guys, right now only the 4 is causing the misfire. I am currently looking into getting the different disks, and the bleed off if it is possible with the Vortech FMU. I was looking at a buddy of mine camaro mag at work last night and they did a write up on the vortech FMU, and it looks like they like that FMU for a super charger and a turbo charger setup on F-Bodies. So given the adress and number in that mag i will give them a call and see what they say about shipping me the parts i want. Thanks again for all the help!
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28793, RE: Plugs loading up, need some advice Posted by XtremeRS, Aug-14-02 05:04 AM
If your only getting a misfire in #4, then its not fuel related IMO. Look into plug wires, coil pack, and do a COMPRESSION TEST!! I'd be willing to bet you have very low compression in that cylinder. Most HG failures come from the #4 cylinder too...check it now! Good luck.
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28794, RE: Plugs loading up, need some advice Posted by 98RsT, Aug-14-02 07:19 PM
Well it is quarter after one in the morning but when i get up at 6 that will be the first thing i do is a CT. oh please oh please don't be my head gasket. That is a pain the the ass to replace.
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