1999 Chevy 3500 Express Hard Start, Fuel Pressure Regulator or Leaking Injectors?

[Joey-D]

I just purchased a 1999 Chevy Express 3500 14' cube truck. Barely broken in with 323K on the vortec 350. If you try and start it normally it, it will just crank and you can smell the fuel. If you just barley bump the key, normally by the 3rd bump its starts and runs like a champ. I haven't even put a mile on it yet or spent much time diagnosing it. I have hooked a fuel pressure gauge up to up though.

Key On Position (priming) 52 psi
Running 50 psi
Shut off jumps to 58 psi
Hour later it has dropped to 24 psi

I am reading this as the injectors are worn and the fuel is bleeding off into the cylinder. Or do you think it is the fuel pressure regulator? Either way, aren't these a combo unit on the new spider assembly that converts it from to mfi?

[speedygonzales]

Your problem is simple. You're not getting good spark. At least a cap and rotor change is necessary. They go through them like Hitler through Poland.

Might want to consider a complete tune up with a new coil, wires, fuel filter, new front O2's and an air filter unless it looks good. And remove and clean then replace the heat sink compound on the ICM.

[Joey-D]

But what about the bleed off of the fuel pressure?
Posted via Mobile Device

[speedygonzales]

Nope not your problem

If the injectors were leaking let's say, you would smell fuel in the oil.

Guarantee you have a spark issue and the cap and rotor is the place to start.

I've been through this numerous times. Day after xmas was the last time. Xmas day no problem. Next day, won't start. I know from my pillar mounted fuel pressure gauge, pressure was good. So I pulled the coil wire and plenty of spark. Drove to Napa, got the best cap and rotor, installed and drove to family.

Trust me on this one.

[Mr.Hatch]

Had a similar issue with pressure drop on my 98 350 1500 - although mine dropped way faster than yours. Replacing the fuel pump fixed my issue.

[Joey-D]

I get your theory and a cap and rotor is cheap enough to try it and super easy to install with it being a van body, but I don't think it would start with a bump of the key if the spark was weak. It's when I hold the key down and smell fuel that it doesn't start.
Posted via Mobile Device

[Joey-D]

Plug is fouled. Still don't understand why the fuel pressure is leaking off.

[95 S_Trucker]

That's from burning oil. If it was getting too much fuel it would be black. with 323,000 on it, I would say its burning oil.

I agree that you do not have a fuel pressure problem. If the regulator was leaking, it would run like crap when it would first start. You would most likely have rich codes, and cyl 3 and 5 misfire codes.

I would consider your fuel pressure drop normal. Its not out of line.

Any pics of the cap or rotor?


It will smell like fuel when it doesn't start because the fuel isn't being burned.

[Joey-D]

Hell with it, I plan on lending this truck out to customers. Just ordered MFI conversion fuel injection spider, intake manifold kit, plugs, wires, cap and rotor.

[allengator]

did you resolve your problem?