1997 GTS won t idle

[GregM]

For those who know my situation I recently purchased a 97 GTS with a little over 10,000 miles. I was advised about putting on a trickle charger but have not done so yet. The battery is an issue apparently and I’m trying to figure out if it needs to be replaced. The previous owner told me it’s about four years old. When I came out to take the car for a drive last Saturday it was dead. I boosted the car and it started right up. I drove the car probably 20 to 25 miles mindful of keeping the RPM above 2000 so that it could charge the battery. It restarted twice, I parked it Saturday.

I came out today and the battery was again dead. So I’m figuring that this battery probably needs to be replaced, but that’s not my question. With the booster on the car and not touching the gas it would crank and start but stall as soon as I let go of the key. If I feed gas it runs but stalls once I let go of throttle. I know that the low battery plays games with the PCM and the car has been running rough which I have been told is the PCM relearning the idle mixture due to low battery. However I am very concerned with the car not idling. Could this be low amperage to the PCM? I hope that the boost that I used has not damage it because I’ve read that on here as well. It is not a charger but strictly a Booster .

I’m currently charging the battery with a battery charger. If the car cranks but will not idle I’m up shits creek.

Help!

[GregM]

Here is booster I’m using. On charger battery drawing 5 amp charge.
Attachment 36830

[Steve-Indy]

Good to speak with you...and, I will bet your car is FINE. Have a good trip to the battery store...call me for all the socket sizes necessary if you like.

[GregM]

Seriously Steve, you’re like a superhero. As usual you were correct. I gave it a 12 amp charge for roughly 45 minutes and started right up. Idling beautifully. Unfortunately I’m not gonna drive it since my booster needs to be charged and I’m not risking getting stuck again. I am heading to AutoZone for a new battery. Thanks again for the assistance and I will just keep you on my list of contacts to go home whenever I have an issue. ��

[Red Snake]

It’s almost always the battery. Gen IIs are extremely finicky with a low battery. Glad you got it figured out.

[Steve-Indy]

Thanks for the followup !!

[mackzilla]

Nice work Steve

[Taximan1]

Battery.... yes.

Or if it's a 1997, high idle or rough idle. Almost always the intake manifold gaskets

[BLRDViper]

When I bought my 97, it did exactly what you described. Did not want to hold an idle and ran rough.
Battery fixed mine along with some driving to get everything reprogrammed.
BLRD

[GregM]

Yes idle is still rough but from my reading here that’s likely due to the low voltage and PCM. Then again this car has 10,300 miles and likely original wires and plugs...would benefit from a tune up this spring. And a battery : )

[BLRDViper]

Greg, give it a little time and some driving and it will get better. Also, remember that the 97’s have the “lumpy” cam and is normal to have some engine shake when sitting at idle. Kinda like a Harley.
My 97 has about 18K still with original wires and plugs.
First thing I would do is get all the fluids done and get the old plastic power steering pump pulley off. Contact Jon at Parts rack and he will get you set up with a new pulley.
Do not forget to check the date on those tires and get them off if they are getting over 5 years.
BLRD

[GregM]

Good to know your still on original plugs and wires. Motor shakes so much it causes hood to drop if open.

I have heard about that plastic ps pump pulley. Have to check that out.

I was told all fluids from front to rear changed 4 years/ 3k miles ago.

[Viper87]

My 97 has a healthy idle and Id say rumbles/lopes pretty good at idle. I don't have anything to compare it too but there's not check engine light and it runs well.

I recently purchased mine about a month and a half ago and have started updating it. First thing was replace the 15y/o tires. Then I went on a spending spree and you can buy a lot for $1,400 that I'd recommend to upgrade/update. I purchased/install the billett power steering pulley and pump bracket, new power steering pump and high pressure power steering line, new spark plugs and plug wires, and skip shift eliminator.

I am waiting for more parts to trickle in and have purchased new intake manifold gaskets, new/cooler thermostat, thermostat housing gasket, PCV grommet, short throw shifter, shifter lowering kit, shifter cup bushing, and new valve cover gaskets.

Next I will upgrade the coolant system, no over heating yet but obviously want to jump on that before so I'll be ordering silicone coolant hoses, will send out OEM radiator to be cleaned/add a 3rd core, and probably look for a later Gen2 cooling fan asy.