99 Tahoe 5.7 Won't Start

[jbangelfish]

Have a 99 Tahoe 5.7 (159k miles) that has given me alittle trouble lately. Trouble began on a cool damp morning when the truck turned over but would not start, sputtered alittle. I ran the battery down and thought maybe it was getting weak, was a few months past warranty period. Decided to buy a new battery, did so and the vehicle started fine with the new battery and worked fine for about two weeks.

 

Went out one wet cool morning and the vehicle acted just like it did before I replaced the battery, sputtered but would not start. Sometimes it would sputter, start and run fine. Now I'm just dead in the water, won't even sputter. Dry days acted normal and drove it with no trouble. Now in a long cool damp spell and nuttin goes.

 

I replaced the cap and rotor, no difference.

 

My alternator used to chirp like a bird (or at least something under the hood did) intermittently, some days worse than others. I hear lots of chevys doing this. My son had said to replace my battery ages ago and this chirp would go away. I always told him if it starts the truck, I'm not replacing it. Funny thing is, the chirp was gone for about 2 weeks with the new battery. Chirp came back and my starting problems did as well. I took the alternator off yesterday and had it tested by a very reputable rebuilder who I have used for many electric motors, starters and alternators. He says it checks out OK. He takes them apart as well as spins them, very thorough and no charge unless he has to fix them. Hard to find guys like that.

 

Anyway, don't know what to look at next, don't want to tow it just yet, am thinking of ignition module or possibly coil. My son put his computer to it and it just says ignition trouble. Maybe I should try my wife's key instead of my own, just thought of that actually.

 

Fuel pump is fairly new and does sound OK with the key. I know there can be fuel problems as well.

All this computer stuff is great when it works, hard to track down when it doesn't.

 

Any ideas? Thanks,

 

Bill

[C. Charles Hahn]

My alternator used to chirp like a bird (or at least something under the hood did) intermittently, some days worse than others. I hear lots of chevys doing this. My son had said to replace my battery ages ago and this chirp would go away.

 

Most likely that chirp is actually your idler pulley.... those are a VERY common thing to hear on Vortec 350s -- my buddy has a 99 Tahoe with 279K miles on it and it's done it ever since he bought the truck with 185K on it. We just pull the idler off periodically and grease the bearings.

 

Anyway, don't know what to look at next, don't want to tow it just yet, am thinking of ignition module or possibly coil.

 

That would be my vote as well. Again with my buddy's '99, we had to replace the coil at 250K miles because it was exhibiting a similar condition to what you describe; between that, the cap/rotor, and plugs/wires it runs like brand new again now. The ignition module was fine, as it should be in your case as well most likely.

[jbangelfish]

My alternator used to chirp like a bird (or at least something under the hood did) intermittently, some days worse than others. I hear lots of chevys doing this. My son had said to replace my battery ages ago and this chirp would go away.

 

Most likely that chirp is actually your idler pulley.... those are a VERY common thing to hear on Vortec 350s -- my buddy has a 99 Tahoe with 279K miles on it and it's done it ever since he bought the truck with 185K on it. We just pull the idler off periodically and grease the bearings.

 

This is what I always told my kid but he insisted it was battery or alternator. Just odd that it went away for awhile with a new battery, maybe just coincidence.

 

Anyway, don't know what to look at next, don't want to tow it just yet, am thinking of ignition module or possibly coil.

 

That would be my vote as well. Again with my buddy's '99, we had to replace the coil at 250K miles because it was exhibiting a similar condition to what you describe; between that, the cap/rotor, and plugs/wires it runs like brand new again now. The ignition module was fine, as it should be in your case as well most likely.

 

 

Thanks, good to hear that the ignition modules are good. They are a problem in Fords. Probably will pick up a coil first. Wires, plugs and full tuneup not too long ago. Another concern is that I bought a "standard" brandname cap and rotor. Never heard of it but the dealer said good as delco, I've heard that before and had trouble with them even fitting properly. Can't find moisture in it though, so maybe OK. Thanks again,

 

Bill