Where is the fuel pressure relief valve on a LB7 Duramax?
The lb7 motor as a FPRV just like the lly and lbz motors, except its in a harder to get to location and most of the time its not needed anyway. The location of the FPRV is located on the fuel junction block in the middle of the valley underneath the metal turbo inlet.
What does a race fuel valve do on a LB7?
PPE Race Fuel Valve (LB7) This valve helps maintain fuel rail pressure during high engine load conditions it eliminates DTC codes P1093 or P0087 (low fuel rail pressure during power enrichment) that are caused by insufficient pressure relief valve spring pressure opening, returning fuel to the fuel tank.
What should lb7 fuel rail pressure be at idle?
For starting a Duramax, you’ll need a minimum of 1,500 psi fuel pressure at the rail while cranking and at idle a minimum of 5,000 psi.
What does a race plug do on a Duramax?
Registered. The PPE race valve increases the fuel pressure relief point in your fuel rail, i.e. how much pressure it can handle before it dumps back to your fuel tank. Unless you’re getting a DTC P1093 or P0087 usually there’s no need to mess with it.
What causes high fuel rail pressure on lb7?
1) Open or poor connections at the MPROP (FPR) connector-pigtail or main engine harness connector will cause loss of pressure control, maximum rail pressure at idle. 2) A stuck MPROP (FPR) can cause excessive rail pressure. 3) Bad suction valves in the high pressure pump can cause rail pressure to be excessive.
What causes a Duramax to idle rough?
Rough idle can be caused by bad engine mount– exhaust contacting the frame, bad injector, or weak cylinder compression.
How can you tell if your TPR valve is bad?
Excessive noise: If your hot water heater is rattling or emitting a high-pitched whistling noise, it’s likely the sound of steam trying to escape the tank, which is a sign of far too much pressure pressing against the inner walls. This means the relief valve isn’t doing its job and may need replacing.
What is a race valve for a Duramax?
This valve helps maintain fuel rail pressure during high engine load conditions. It eliminates potential low fuel rail pressure DTC codes P1093 or P0087 (low fuel rail pressure during power enrichment) that are caused by insufficient pressure relief valve spring pressure opening, returning fuel to the fuel tank.
What is an LB7 fuel pressure relief valve?
LB7: LB7 fuel pressure relief valve. Well this is the elusive LB seven fuel pressure relief valve. It’s so special that the dealer wants about $700 for it. It’s only sold as part of the fuel rail junction block. None of the shim kits or fuel race plugs available will work for the LB7 I don’t believe.
Are there any fuel race plugs for the LB7?
None of the shim kits or fuel race plugs available will work for the LB7 I don’t believe. (Correction. PPE has a plug. Not sure if there is a shim kit for the LB7)
What are the symptoms of a bad fprv on a Duramax?
Watch how we test a faulty fprv on an 01-04 LB7 Duramax. Symptoms were hard/no start, long crank time, white smoke. Very little loss of power noticed. Truck has FASS pump no other upgrades