EGT's or Fuel Rail preasure relief valve issues?

**jt_cummins** · 01-20-2013

OK, so I have been talking with steve about my EGT's going to high and my truck defueling. It has happened to me twice First time being when I manualy shifted and didn't shift fast enough between first and second gear. And the second being when I did back to back to back 1/4 mile pulls and my EGT's hit 1552* So I have been think it has been my EGT's but did some reasearch.

I think what I have is not related to my egt's as much as it is to the fuel bypass valve in the fuel rail. The two go hand and hand but are different. When I bounced it off the rev limiter my fuel pressure went way above what the relief valve could take and it popped open. When it pop's open it throw's the over head code for service. At the same time your egt's was sky rocketing. Once open it feels like the truck defuels until it resets. The rpm's have to come down below about 1500 or so then it resets and your good to go until the next time like when I was doing back to back pulls. It was very frustrating for me. Sense I can monitor my fuel rail pressure, through my CTS screen, I would be able to see when it happens. There is a racing plug kit from Sinister that is supose to take care of this problem.http://www.rollinsmokediesel.com/pd-...-rail-plug.cfm
So after all that what do you guys think??????

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**Polaraco** · 01-20-2013

I don't know. But it sounds like you have your fueling set too high on your EFI. Or the timing may have a play in that too

The interesting thing is you say it doesn't smoke alot. You should be blotting out skylines.

Do you knw what the pressure is when the bypass pops?

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**jt_cummins** · 01-20-2013

Still trying to find that. There is block off valves that block it off completely but that kinda bothers me.

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**Rockwerx** · 01-21-2013

I would shim it rather than block it off...way safer and your injectors will last longer. Any time I have helped modify a 6.7 with a tuner we have shimmed the relief valve or it would open. Also, the more times that the relief valve opens the less life it will have...so it is best to do it sooner rather than later when running a tuner.
Good luck!

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**Polaraco** · 01-26-2013

I was talking to Tyler tonight. He apologized for not getting back to you sooner.

I would suggest you replace the plug with a new modified one. The relief in there now will degrade if it pops allot and it sounds like you have popped it several times. I've seen valves like that elsewhere that weren't worth a crap after 5 or 6 times. Like the pressure relief on an air compressor. After 4 or 5 pops they have to be reagjusted. If possible.

Tyler can get you one. He also has the Fass and air dog lift pumps.

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