Strange Driveability problem

**SSPORT** · 10-05-2006, 04:27 PM

Any ideas on this?

Four days ago, my 2000 Camaro SS starts doing strange things on startup. Although it has a new (3 month) old battery, and the starter cranks well, it takes a second or two to catch, which it normally doesn't do.

Then, backing it out of the driveway (flat, maybe a 1% grade), it wants to stall in reverse. Then the tach quits and flatlines, even thought the motor is running fine. Then the tach comes back online.

Then it stumbles when going into an extreme lefthand corner at low to moderate speed in 4rd gear.

Now this evening, it repeats most of those symptoms, then quits on me on the road. I was able to restart it, and drive a half mile to a convenience store, and when I pulled in the lot, the motor quick again. Died. Wouldn't start, although it cranks fine. Tried a couple of times, then let it rest for 2-3 minutes, then it started right up like nothing was wrong. Once it was really warm (the motor), nothing happened, it runs fine. I got it home and shut it down, let it rest, restarted a few times, no problems. Idles smoothly, revs fine. So it seems that this is only when cold, or not up to temp. Can't be plugs or it would not idle or run smoothly. Oh, and the SES light did NOT go on during all this, so I don't think it's thrown a code (too bad!).

I am suspecting something in the fuel system (although that tach quitting issue isn't consistent with that...). This is in New Hampshire, and the ambient air temp the past few days has been low 40s at night, mid 60s daytime, more or less.

Any ideas? I want to give the service department someplace to start looking. Car has 85K miles, but only 42K miles on a new LS1 motor. Probably due for a fuel filter change, and has a bad fuel tank sender unit, but that's about it for routine maintenance issues or known problems. The only other thing is I went over a SEVERE bump in a highway construction area, so bad the rear axle hit the bump stops pretty hard. Wondering if that might have loosened any electrical connections, like a fuel pump ground or something?

**96z28** · 10-05-2006, 10:00 PM

Make sure the simplest things are done. For example; the battery terminals, make sure they are tight. I had similar problems on my 9628. Check the ground wires also

**SSPORT** · 10-06-2006, 07:00 PM

Originally Posted by 96z28

Make sure the simplest things are done. For example; the battery terminals, make sure they are tight. I had similar problems on my 9628. Check the ground wires also

It's not the battery, it cranks fine, the plugs spark evenly, all the auxiliary stuff, heater, radio, lights, work fine -- when it runs it runs smooth as glass. It's just that it suddenly dies when cold, after driving for maybe a mile, maybe less. Then starts up again on a key turn after a moment's resting. Clogged fuel filters? Maybe a bad ground on the fuel pump?

**SeVeReDiStOrTiOn** · 10-06-2006, 10:35 PM

Check the fuel pressure/change fuel filter and spray some electrical cleaner on the maf filaments while you're at it. It does sound like a fuel prob like you said so start there...you should be able to rent a fuel pressure gauge at autozone

**SSPORT** · 10-07-2006, 06:08 AM

Originally Posted by SeVeReDiStOrTiOn

Check the fuel pressure/change fuel filter and spray some electrical cleaner on the maf filaments while you're at it. It does sound like a fuel prob like you said so start there...you should be able to rent a fuel pressure gauge at autozone

I was planning on changing the fuel filter but I hadn't thought of the MAF sensor, I'll clean that too, thanks. It's very strange how the car dies like it was hit with an axe, and then key-starts right up again with not so much as a stumble.

**SSPORT** · 10-14-2006, 09:19 PM

Here's what was wrong:

(the car got stranger adn stranger -- would not start at all on Sunday, Oct. 8, then started fine Monday morning.) Got it to my dealer under its own power on Monday, Columbus Day, and left it there with a description.

It was fixed and ready for pick up Tuesday mid afternoon. The problem? The wiring to the crank position sensor switch was damaged (in the area near the starter), and hanging on by only two strands, if that (said my mechanic). When touched with a finger, it separated completely. Must have been a One in a Million hit with a stone or something, and could have been damaged a while ago, and just wore gradually. A wire splice is all it took to set things right!

Happy about that!

Originally Posted by SSPORT

Any ideas on this?

Four days ago, my 2000 Camaro SS starts doing strange things on startup. Although it has a new (3 month) old battery, and the starter cranks well, it takes a second or two to catch, which it normally doesn't do.

Then, backing it out of the driveway (flat, maybe a 1% grade), it wants to stall in reverse. Then the tach quits and flatlines, even thought the motor is running fine. Then the tach comes back online.

Then it stumbles when going into an extreme lefthand corner at low to moderate speed in 4rd gear.

Now this evening, it repeats most of those symptoms, then quits on me on the road. I was able to restart it, and drive a half mile to a convenience store, and when I pulled in the lot, the motor quick again. Died. Wouldn't start, although it cranks fine. Tried a couple of times, then let it rest for 2-3 minutes, then it started right up like nothing was wrong. Once it was really warm (the motor), nothing happened, it runs fine. I got it home and shut it down, let it rest, restarted a few times, no problems. Idles smoothly, revs fine. So it seems that this is only when cold, or not up to temp. Can't be plugs or it would not idle or run smoothly. Oh, and the SES light did NOT go on during all this, so I don't think it's thrown a code (too bad!).

I am suspecting something in the fuel system (although that tach quitting issue isn't consistent with that...). This is in New Hampshire, and the ambient air temp the past few days has been low 40s at night, mid 60s daytime, more or less.

Any ideas? I want to give the service department someplace to start looking. Car has 85K miles, but only 42K miles on a new LS1 motor. Probably due for a fuel filter change, and has a bad fuel tank sender unit, but that's about it for routine maintenance issues or known problems. The only other thing is I went over a SEVERE bump in a highway construction area, so bad the rear axle hit the bump stops pretty hard. Wondering if that might have loosened any electrical connections, like a fuel pump ground or something?