Brief History:

Car has sat for approximately 10 years total without being driven.
Purchased the battery almost 2 years ago when i tried to get it up and going again, but found a ton of issues that needed to be addressed so the car sat for approximately 2 years while I fixed a bunch of issues in my spare time(Broken exhaust piping, new fuel tank, lines, filter, plugs, plug wires, and new 02 sensors).

A few days ago I finally got most everything addressed so I went to start the vehicle and the battery was dead as expected due to the elapsed time from the last attempted start. I hooked up a battery charger to it and charged it for an hour. With assistance the vehicle started. Upon starting, it stumbled briefly for about 2-3 seconds before leveling out and idling nicely.

Once the vehicle idled nicely I disconnected the jumper cables so that the car was running off it's own power. There were no ill affects when I disconnected the jumpers. it stumbled just a tad when I tried to rev it after disconnecting the jumpers but within 20-30 seconds of idling it revved fine. I let the car run for about 10 minutes (idled perfectly smooth and revved freely with the manual tranny out of gear)while checking for leaks and other potential issues then shut it down for the night.

The following day I tried starting it up without jumpers and it turned over for 3 or 4 seconds without starting. I tried again but had to give it some throttle after 2-3 seconds and it started up with the idle fluctuating for 2-3 seconds before I was able to settle it down with the throttle. I gave it a little gas and it was sorto of rough but after about 10-15 seconds I could rev it freely with no issues whatsoever. I let it idle for another 5 minutes and the entire time it idled great so I decided to take it for a drive down the street and back. The car is completely warm at this point and has been running for at least 5 minutes.

After pushing in the clutch, putting the transmission into reverse, and releasing the clutch, the car backed out smoothly. I put the car in first gear let out the clutch go get moving, and the car seemed fine, if not a tad under-powered. The car was smooth through first and second and going into third it started to feel week. By the time I got close to the house, the car was feeling way under-powered and was starting to stall. There was no indications of misfires or bucking associated with misfires, but the RPMs would drop low enough to stall out the engine. I was able to keep it from stalling by playing with the gas pedal but it took about 10 seconds to settle the idle down to normal. In neutral the car now idled fine and revved smoothly again. It was wierd, it was like the engine was starving for fuel, but there wasn't any indications of misfires.

I hooked a fuel pressure gauge up to the fuel rail and did another test drive. The fuel gauge maintained proper pressure throughout the test drive, as well as during the stumbling.

Is it possible that the battery is simply in such a poor state that when I put a load on the engine the electrical system cant handle it? As soon as I let it sit for a few seconds with the clutch in, or in neutral(No Load), everything goes back to normal until i start to put a load on the engine.

I am waiting for a USB connector to arrive so that I can datalog the car but it wont arrive until sometime this week. I am not sure where to start the diagnostics.

Any suggestions until i can do a data log?

 

Did the car sit without running, or did you start it periodically?

My car sat for an extended period with no prep. It hasn't really been driven since October of 2000. Due to "prolonged" issues resulting from a collapsed cat, I bought a new car and parked the Camaro in a garage, where in sat untouched until 2006 or 2007.

When I tried to get it running again, it needed pretty much new everything. In addition to what you replaced, I replaced all of my fuel injectors, optispark, MAF, TPS, IAC, coolant temp sensor, coil, ICM, water pump and who knows what else. There may not be much left.

If your cat sat for 10 years without running, I would definitely check the injectors.

I don't know if your symptoms are consistent with gummed up/seized injectors, but it's something to check. If any were completely seized, it would probably be very noticeable, which was the case with my car.

 

I take it you're running new gas, correct? Ethanol mix gas is only good for about a month in the tank before it starts to get funky.

 

BTC,
For all intents and purposes, the car sat without running for the last 10 years. The car idles and runs perfectly while in neutral(no load), just a little long to start at first. Once I put a load on it, ie driving, its initially fine but looses power progressively until I let off the gas, put it in neutral, and let it sit for a minute at idle. Once i let it sit, ill have full power for a few seconds then the car progressively loses power again, to the point of wanting to die, until I let off, play with the throttle to get it to idle, then let it sit for a few minutes idling. Its like a little cycle. Even throughout this process, there doesnt seem to be any misfires or shaking of the engine resulting from misfires. Its like it simply runs out of power and wants to die until i take the load off of the engine for a little while.

As far as the fuel system is concerned I put in fresh gas, new fuel pump, filter, new tank, FPR, and had the injectors cleaned, flushed and flow tested.

There is no catalytic converter on the car, just headers and stock cat back.

All vacuum lines on the intake are properly fastened with no apparent leaks.

Before I put the car in storage, there were no drive-ability issues with it. The car ran strong and was a daily driver.

No codes are being thrown.

I had a similar situation on a motorcycle and it turned out to be the battery, but I would rather try to diagnose than throw money at the problem blindly. Hopefully the data logger will give me some idea in a few days.

 

My car would idle and rev fine when we first got it running again. As soon as you put any load on it, you would have thought it was going to explode. It was backfiring, misfiring etc. A new opti resolved all of that. My water pump had been "weeping" onto the factory opti before I put it in storage, and it was in really bad shape after sitting for years.

I actually drove my car today for the first time in 17+ years. I promptly took it to the gas station, filled it up, and learned that the "brand new" Spectra gas tank we put on it is leaking, apparently from around the filler neck. JOY. I hope that can be fixed without taking the tank off, buying a new tank etc.

Other than the issue with the gas tank, it seemed to be running well and was fun to drive. It had been a LONG time.

 

What is your battery gauge doing? You should poke around with a volt meter to see what voltage the battery and alternator are at. I'm going to go out on a limb and say that battery is beyond fucked if it sat for 10 years w/out being charged.

 

I apologize if I mis-stated or was unclear, but the battery was purchased a little over 2 years ago but sat basically unused, except for any draw that the car might have had during that time. I think im going to go ahead and purchase a battery and if it doesn't solve the problem then I'll know for sure.

 

Use a volt meter first before getting another battery. Even if it's two years old if it hasn't been charged in that time could still be an issue. See what voltage is from the alternator and then from the posts of the battery while its running and then take a reading after the car is immediately shut off.

 

Will do, thanks.

 

good battery should DVM test at 12.xxx VDC and 14.xx with car running checking with DVM at battery terminals. You can test for alt vdc out by using the DVM on alt + post and the other to ground

If the battery alone is now 11.xx volts because of none use it likely would come back to life with a trickle charge or just driving for a period of time with a properly operating charging system

 

Thanks. Ill check test the battery and alternator tonight and I'll be hooking up a load tester to the battery as well to check for voltage drop under load.

 

I think I've put three batteries in my car since I pulled it out of storage, most recently this past Saturday. The battery I just replaced was six years old and would no longer hold a charge, but the car seemed to run ok once it was started. Having said that, I didn't actually drive the car with the bad battery, so no idea what might have happened under that scenario.

Batteries have gotten expensive as a ****.

 

Everything checked out fine with a multi meter but when I put the battery on a load tester the voltage plummeted. I took the battery to Autozone and they charged it for me. The problem is still present but it is MUCH better.

I am now experiencing some surging during acceleration which I wasn't getting earlier.

Sucks, but Ill just have to wait for the diagnostic tools to arrive this week and post the data logged.

 

If the voltage does not hold under load then the battery is bad. Change it out.