[sybrknite]

I have a 1998 Chevy K 1500 Silverado that will not start after sitting for over 12 hours once started there are no problems except the check engine light that will not go out. It started becoming hard to start last weekend and within 3 days it won't at all without using starting fluid. I have been told by the guys at AutoZone who used a scanning tool to get a P0452 code, that the fuel tank pressure sensor might be bad. It is on the top of the tank and a new sensor costs about $35. I just changed the fuel filter and put new plugs in now it starts better but still no change after sitting over night. Is this code correct or a symptom of something else?

Havin' trouble in S.A. Tx.

[TxGreaseMonkey]

Code is likely correct. I would replace the sensor and after several start-up cycles the CEL should go out on its own--if not, AutoZone can clear it for you with their code reader.

[medic-dan]

The fuel tank pressure sensor is part of the EVAPorative emissions system and while it can cause the check engine light to come on, it probably is not the cause of your starting problem. Basically, it check to see if the gas cap is on. It really doesn't do anything until the engine is running.

How many miles are on it? Have you ever replaced the fuel pump?

First thing in the morning when you turn the key on, but before you try to start it, do you hear the fuel pump running for a few seconds?

It might also be a tired fuel pump having trouble building pressure.

Check the fuel pressure and see what it's doing. You can put a gauge on the fuel rail and check it.