Grasping at straws...can a car battery affect performance?

[travis]

Some of y’all may remember my multiple posts about issues I’m having with my ‘99 Suburban C2500. If not, here is the quick and dirty version...

Driving home from work one morning, the engine falls on its face and is popping out the exhaust like crazy. Eventually ended up replacing the crank and cam position sensors, fuel pump, O2 sensors, intake gaskets, injector assembly, cap, plugs, wires, fuel pump, etc etc. It runs “better”, but still not right. Idles dead smooth all day long, at light throttle cruise it is still rough running and down on power. WOT pretty good for what it is but still feels off to me. I was done messing with it...parked it around behind the barn and planned on parting it out or scrapping it after I pulled what I wanted off of it.

The wife found someone interested in buying it, so I’m a last ditch effort to get this thing running right (so I can at least recover some of my losses on this thing) I pulled and cleaned the EGR valve, and dropped the tank and drained it (the exhaust smells a little funky) as it still had the same tank of fuel that was in when this whole mess started. Put it all back together, put fresh gas in it, hooked the battery back...and it just clicks.

I’ve gotten in the habit over the years of disconnecting the battery on anything that sits for any length of time. I put a new battery in this suburban 1 year ago. I had to replace it in January of this year because it wouldn’t hold a charge. The January battery was fully charged and disconnected when I parked this thing a couple months ago. Hooked it back up and it is super weak...put a charger on it and the gauge on the charger is bouncing between full and half charged (same results with both my chargers). Looks like this one is going to get replaced again.

Could there be a correlation between these junk batteries and the way this thing is running?

[Schurkey]

Sure. There COULD be a connection.

No promises that there IS a cause-and-effect relationship.

Stuff a new battery in it, and see what happens. Remember that the computer may have to re-learn all the fuel trims and such, which can take a little time.

[Carnut1]

Yes

[rebelrouser]

Not so much the battery, but an alternator with a weak diode can cause stray AC voltage to affect the computers and modules in your vehicle. Real easy to check, just put a volt meter across the battery terminals, set meter to DC volts, start the engine, turn all loads on, Meter should maintain around 14.2 volts DC, then switch meter to AC volts, it should read less than .5 volts AC, if it reads over you have an issue. My 99 Dodge truck will start shifting the transmission weird when the alternator gets weak.


http://assets.fluke.com/appnotes/automo ... atbook.pdf

[n2xlr8n]

Make certain that your signal and power grounds are good.

Put your meter on AC and read the battery voltage with the car running (looking for noise- anything under 100mv is fantastic).

I've had several issues where the battery was causing conflict, especially with EFI cars. One with the exact symptoms you describe.

[englertracing]

If a shit battery has been subjected to rough treatment there could be intermittent connection.

Had a truck that would intermittently die for 1 or 2 seconds about 5 times every time I drove it.

When it got a new battery problem went away.

[JoePorting]

I'd replace the alternator and consider replacing the cats.

[rockosocko]

Do some research on "The BIG 3" on Youtube (greatly increasing wire quality AND size) in addition to adding a few ground straps of GOOD quality.
Doing this really helped with my son's '01 Cherokee (with winch, numerous LED's etc..)
I have a Lexus IS300 that seems to be running just fine, But want to do this to just to see if it will Operate/run any better.
(not that it's a hot rod. More for better efficiency, and cooler running Alt/Battery. Here in the South, the battery's will evaporate a good amount of water from the wet cells, and need periodic attention)

I had a '97 extended cab that had grounding issues/Gremlins. And part of that was little,TINY ground wires INSIDE of the Vortec ECU. There are 4 separate plates inside of it that have those ground wires connecting it all.
Ebay sells ECU 'services' that you send in yours and they send you a re-soldered/tested one back.
I found this out AFTER selling my truck in frustration with new spiders, cap, wires etc..
Also, you know that you need a computer/tester to re-stab the distributor in? It HAS TO be done right to get it to run correctly.
But yours being a '99, is it the LS style motor or the 96-99 Vortec?

[Krooser]

A buddy chased an engine miss in his dirt car motor..
Intermittent...new MSD, coil, plugs, wires, valve springs, fuel pump, dizzy...all the usual suspects.

Then one night the car would not crank...installed the battery from his pickup and the deal was fixed!

[travis]

I pulled another good battery out of one of my other trucks...engine cranks good, lights off, then dies. It’s triggered a P1626 code (something about the anti-theft system not communicating with the PCM or something like that). This has happened once in the past...last time I was able to just clear the code and didn’t have any more trouble with it. Now...it won’t clear...

This is getting ridiculous...

[hysteric]

Make certain that your signal and power grounds are good.

Put your meter on AC and read the battery voltage with the car running (looking for noise- anything under 100mv is fantastic).

I've had several issues where the battery was causing conflict, especially with EFI cars. One with the exact symptoms you describe.

Met a guy with an Alfa 147 GTA that would break down at the same spot on the freeway on the way to work. Would have to wait a while before he could get the car going again. So he took it to various "specialist" workshops to get fixed and spent thousands on a new computer and other parts from memory about 8K he said. None of which fixed the problem

I told him it sounded like a high resistive join and to check all his earth connections. Should have seen the look on his his face when he came back and said he found exactly that, a loose earth.

[ProPower engines]

1999 ia YEr where the battery condition has to be great or there will be running issues. the battery is to start the truck and supply voltage all the time while the alternator maintains the battery's voltage level during operation.

A bad battery will cause the alt. to try to run everything where there is not enough voltage and burn it up over a short time. I see some guys swap batteries from truck to truck all the time and just ruin batteries constantly from over tightening the cables and running it flat then fast charging it again and again till it gives up. They they have to replace the alternator
as well as the battery to get it to run right again.

Check the output of the alternator after a fresh battery is installed. Confirm the amp. output of the alt. in the truck
and if its lower then spec replace it.
Those trucks have several ECU's in them for the bod6y dash trans and engine depending on the options when new but anything with air cond. power windows + seats and brighter head lights needs a big amp hour battery. I would go with a 850CCA battery to be safe if you are selli9ng it to a know person or not just to be sure the tail lights are seen on the way down the road as you wave so long

[jake197000]

test,dont guess.

[S10LS2]

I pulled another good battery out of one of my other trucks...engine cranks good, lights off, then dies. It’s triggered a P1626 code (something about the anti-theft system not communicating with the PCM or something like that). This has happened once in the past...last time I was able to just clear the code and didn’t have any more trouble with it. Now...it won’t clear...

This is getting ridiculous...

You have to do the vats relearn procedure. turn key on engine off leave for 10 minutes. Might have to do it 3 times and on third time when anti theft light goes off start it. google the eact procedure. First thing I do when I tune a gm roughly this age is turn the vats off in the ecm. Or you may now need to do a crankshaft relearn function to get the truck started.Because you replaced the crank sensor. One of those 2 issues is your problem and clearing the code will not work.

[travis]

You have to do the vats relearn procedure. turn key on engine off leave for 10 minutes. Might have to do it 3 times and on third time when anti theft light goes off start it. google the eact procedure. First thing I do when I tune a gm roughly this age is turn the vats off in the ecm. Or you may now need to do a crankshaft relearn function to get the truck started.Because you replaced the crank sensor. One of those 2 issues is your problem and clearing the code will not work.

Thanks. I did find this procedure with a google search after sifting through tons of doom and gloom (replace the PCM and VATS, only a dealer can fix it, etc).

However, there is more going on here...I did some troubleshooting this morning and am seeing a couple issues I’ve got to figure out. 1st, it looks like the starter is all of a sudden drawing a huge amount of amps when cranking, and I have a very high parasitic drain on the battery. I tested the drain for 3 minutes...I’m seeing 272mA drain for 1 minute, that drops to 172mA after 60 seconds and stays there. The 100mA drop after 60 seconds appears to be normal (computer and what not going to sleep), but the remaining 172mA draw seems very high although I can’t find any “factory spec” for what it should be. I’ve got more troubleshooting to do but I suspect that the alternator may have a bad diode in it.