davescountry

Hello all -

I have a problem with my 2000 Z71 Tahoe. I think I know which direction to head, but thought I'd throw this out and see if anyone had different thoughts.

First, this is a 2000 Tahoe (old Style), z71 with a 5.7. Truck has about 240,000 miles on it.

SYMPTOMS
The problem is hard starting. On a normal day, I have to crank the engine for a few seconds while feather the gas, then let off after about two seconds. I repeat this, and after 2 or 3 tries, it catches. The truck seems to run fine, although my mileage has gotten terrible and I am getting maybe 12 mpg, highway or city.

On cold days, first thing in the morning, it starts fine with barely a tap on the key. If I start it within 5 mins of turning off, it starts fine. The warmer it is outside, the harder it is to start.

I do seem lately to be getting a whiff of coolant odor here and there. Also, occaisonally it will get an SES code, which I checked and came back with random misfire. This happens maybe 10% of the time, generally after a particular hard start.

DIAGNOSTICS
- Problem started in late summer, I was getting a code that indicated I needed new catalytic converters, which I had put on. It did not change the problem. (Mufflers were replaced one year before).
- Mechanic ran the codes on his machine and could not find anything.
- On his reccomendation, I ran Sea Foam through the manifold, changed cap, rotor, plugs, wires, fuel filter. I thought there was some intial improvement, but its hard to tell.
- Put a gauge on the rail and I believe I am getting about 65PSI to 70PSI on the fuel during crank. Fuel pump was replaced about 2 years ago and sounds fine when cranking (meaning I can hear it kick on)

Based on reading, I am leaning towards the fuel pressure regulator. If I understand correctly, this is under the manifold. Part of my hesitation is that I would hate to go through all of that, then find out it is also a spider assembly. On the other hand, I'd hate to drop a few hundred bucks on an assembly I don't need. I have debated getting a new regulator, then seeing if I can find a spider assembly used that looks decent. I figure if nothing else, if the problem is fixed, great, and if it changes the symptoms then I would know its the spider assembly.

Anyways, I'd like to hear thoughts. Short of taking it back to a mechanic, I don't have access to any other diagnostic tools.

Thanks in advance for the help.

kevinkpk

Since the cat was replaced, I'd too lean towards the regulator. My understanding is they are difficult to replace.

zhowiez

I have the same exact problem on my 2000 C3500 5.7 do anyone have any other opinions on this???