HELP!! Fuel pressure to high!?!

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HELP!! Fuel pressure to high!?!

Postby freak007 » Sun Jul 03, 2011 6:11 pm

Posting from cell phone while driving... forgive the shorthand...


92 ctd - installed low pressure piston pump 2 years ago. Has always shown 17 to 20 psi at cruise, but could suck it to 0 if WOT For too long.

No recent fuel system mods. Added water/meth and changed rear gear to 3.73 two days ago.

Isspro performax gauge now showing 30 to 35psi after.the filter. WOT only brings it to 20.

Truck seems to be running a littl rough, especially at idle, but absolutely no loss of power.


Please help, I still have 1500 miles to go and it is a holiday weekend... FML
'85 Crew Cab with '92 CTD running gear. Rebuilt Getrag, SBC ConO, A1 studs, 5x.014s, HTT 62/65/13, Diamond Eye straight pipe exhaust, BHAF, pump tuned, timing advanced 3/8", KSB hotwire = 353/747. Since added M2 fuel pin and timing spacer, PDI manifold, Ported/O-ringed head... 400 club here i come ;)
freak007
fuel screw!!!!
 
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Re: HELP!! Fuel pressure to high!?!

Postby Richie O » Sun Jul 03, 2011 6:55 pm

If you shut the truck down, does the gauge go to 0 ?
1989 W250 727, 3.07 L/S, S300, P/S Intercooler, Stans exaust, Pump adjustments, 127k miles,297 hp
1993 W250 extended cab, rag, 4.10 l/s, 6x16's, HTT 62/71/14 piston l/p, Isspro EV series tach, fuel pressure, boost, oil pres, water temp, volt, pryo, 132k/ 301 hp
1992 W250 with NV4500, 3.54's, 16cm 60mm GDS H1C, ground stock cone, Isspro tach, pryo, boost, fuel pressure, slow, rusty, dented,180k
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Re: HELP!! Fuel pressure to high!?!

Postby collegekid » Sun Jul 03, 2011 7:38 pm

where you at and where you headed?
1992 D350 CC LB 5-spd CTD, 366 GSK, Rotated Fuel Pin, Fuel Screw 1 turn off runaway, Factory Match Pyro and Boost, 4" Diamond eye exhaust, and a broken front sway bar :-)
http://photobucket.com/truckytruck
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Re: HELP!! Fuel pressure to high!?!

Postby freak007 » Sun Jul 03, 2011 9:06 pm

Crisis averted!!

Shortly after posting I found a wayside rest so I stopped to check it out...

Initially I did not shut it down because I had been running pretty hard for 6 hours straight...

Checked the oil - no fuel in the oil, so my injector pump had not blown the seal out (yet)
Checked the coolant - full and not boiling
Unplugged the fuel pressure and boost sensors and swapped them - boost gauge now reads 30 to 40psi, and fuel pressure is 0

At that point it had idled long enough to shut it down... So I shut it off and started searching for the restricted return line... 20 minutes later I had found nothing, so I decided to check again and see if the cool down time had helped it at all. I climbed back in the cab and turned the ignition on... a quick glance at the gauges and I see the fuel pressure gauge is sitting at 18psi :banghead:

Long story short - I have a biased sensor and the truck is safe to drive


Richie you were on the right track. Too bad you didn't respond earlier, you could have saved me 30 minutes ;)
'85 Crew Cab with '92 CTD running gear. Rebuilt Getrag, SBC ConO, A1 studs, 5x.014s, HTT 62/65/13, Diamond Eye straight pipe exhaust, BHAF, pump tuned, timing advanced 3/8", KSB hotwire = 353/747. Since added M2 fuel pin and timing spacer, PDI manifold, Ported/O-ringed head... 400 club here i come ;)
freak007
fuel screw!!!!
 
Posts: 43
Joined: Sat Nov 21, 2009 1:31 pm
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