04lss

Hi All,

I just bought a 99 tahoe 4wd for 1200 bucks. It runs and drives, has a little rust but is mostly sound. 252k.
I have a few questions after driving it for a few days and doing a tune up. For reference, so far i have replaced the spark plugs, wires, fuel filter, I have 2 big bottles of techron in the gas. I also have 2 bottles of HEET in the fuel. So far ive put nearly 400 miles on it since friday. I have an air filter and fan belt waiting to go on.


1. I want to check the distributor timing. I understand that you must use a scan tool to do this. I have HP tuners, and have been able to read cam offset. Is cam offset the same as cam retard, IE the value i need?
2. when the truck gets warm there is a hesitation at part throttle. It gets worse on a steep hill. We found water in the gas when I changed the fuel filter. My initial reaction is that the water is to blame, but why is it only when the truck gets warm?
3. There is an odd noise at idle. the best way to describe it is that it sounds like the squeal a blower fan makes at low speed when it is on its last leg. Its coming from the engine bay. Its not loud. any ideas what i should check?
4. What is unacceptably low oil pressure at idle? if i can trust the gauge (not sure i can since half of them are incorrect) I get 5-10 PSI at idle, and around 20-30 at cruising speed. (when warm) Should i be concerned and looking to replace the oil pump, or should i just leave it? I added some ceratec to help keep things protected.
5. I cant seem to get confirmation one way or the other. Does the engine need to be removed to replace the oil pump?