wolfking42084

Hey guys,
I'm new to the site and I'm not sure i'm in the right thread,but, I had a question about my zr2 truck. For about the past month now, about 1/4 of the times i'm driving, the truck will make a whistling sound the entire trip. When I cut the switch off and crank again, it takes 5-6 times for it to catch and run. Once it catches, I have to keep my foot on the gas pedal of the rpm's bottom out and it will die. It's a pain especially when coming to a stop light and the truck dies just randomly because of this. If I can park it when it acts up, it will sometimes go away and sometimes it won't. It's been to 2 private mechanics and 2 chevrolet dealerships for this problem now. First guy changed spark plugs, fuel filter and air filter. Second guy changed mass air flow and said he didn't know beyond that. Third was the dealership and said it was a fuel pump problem. It just got back from another dealership yesterday where they said it wasn't the fuel pump or the alternator. And knew nothing beyond that diagnosis. I have been thinking alternator all the way cause everytime it does the cranking and rpm problem, the clock resets itself to 1:00 everytime. A friend of mine does some auto stuff and said the oxygen sensor on the exhaust or electrical somewhere. I'm tired of taking it so many places and having to pay for no results. Can you all please help me out?? thanks logan

wolfking42084

Sorry to post again guys, i just need some help. This truck has been to 4 shops now to get fixed and they can't. 2 which have been chevrolet dealerships. this afternoon, it made the whistling sound and when I cut it off, it wont even turn over to crank now. No lights come on or anything. Please help! thanks all

EvansBlue

Thats a weird problem. What is the year model?

wolfking42084

thanks for the reply. it's a 2002. any thoughts

therewolf

Yeah, more than likely you've got some type of air leak from a cracked part or split hose somewhere. Does the noise occur at idle? This sounds like a classic vacuum leak, with the exception of the clock resetting itself, which COULD be caused by running the battery very low, or perhaps a separate problem.

Do you have any trouble codes?

If you can get the vehicle to start whistling, try to localize the sound. Park it with the engine running,pop the hood, and try to find the sound by ear.

Focus on senders and sensors on the intake manifold. Sounds like you've got something with a hairline fissure which acts up intermittently, so you have to try to find it with the engine on, while it's whistling.

EvansBlue

Theres a small chance it could be something requiring a heavy current load, which would ultimately cause you to stall and kill your battery momentarily. The only thing electronic that I could think of that would make a whistling noise would be the fuel pump.

Like rivereye said, its very likely that you have multiple problems. I kinda agree that it could be a vacuum leak even though the OBDII system would pick that up.

I'm not telling you to do this because its dangerous, but I would get can of carb/throttle body cleaner and if I can keep it idling long enough, spritz all the vacuum connections and listen for a change in engine speed (I would of course avoid the exhaust manifold at all costs). If I find a place that causes a RPM increase, I have located the leak.
BTW, that procedure is the alternative to using a smoke machine...

wolfking42084

Ok, thanks guys. It is going to another mechanic today. I;m baffled by all of this. Hopefully the truck completely dying will turn out to be a good thing in locating the problem.