96 Ciera doesn't do well in the heat
 

I have a '96 Olds Ciera with a 3.1. I don't know how well I can explain what it's doing. The cooler the outside air temp. is, the better it runs. I use the car to deliver mail. It will run fine the whole day except if it's really hot out, like above 80 degrees. It sometimes runs a little rough for a while but eventually smooths out and runs fine again.

The problem starts when I get back to the P.O. and turn the car off. When I go out to leave, the car will not start. It turns over strong but won't stay running for more than a few seconds. It acts like it's trying to start on 2 cylinders. There's an odor that smells like a charcoal grill. It will start with a jump. After it's jump started, it runs rough for a few minutes, like it's running on 2 or 3 cylinders, then smooths out and runs fine.

It's definitely related to the heat. Saturday it wasn't real hot out. The car ran rough for a few minutes but it did start the first time. The hotter it is outside, the harder it is to start.

Any help would be greatly appreciated. Thank you.

A couple other things. I rarely get the SES light. When I do, all it says is, random misfire. The car has 197K miles. It's uglier than homemade soap but up until recently, it's never given me any problems. I've put 125K miles on it and it runs as well as the day I bought it.

I've replaced - coil packs, battery - a couple months ago, intake air temp sensor - a couple months ago, plugs and wires - about 2 yrs ago.

You said that when the car is jump started, it fires right up? The same car that cranks over with no issue, but does not start?

The first thing that comes to mind is battery cables. The strong cranking indicates power getting to the starter, but if it will crank all day long, until you jump start it, it seems like power is not going where it should be going.

Would the heat affect the battery cables? If I could let the car sit long enough to cool off it would start right up.

It couldn't hurt to check. If they are corroded, that would explain it. If they are original to the car, it may not be a bad idea to replace them anyway. Not sure if it is related though. If you use the throttle at startup in the conditions in question, does it still run just as rough, or does it clear up?

The other thought was ignition module or Crank Position Sensor, but the crank sensor usually causes a no start condition for a while, not a kinda start condition.

I would check the fuel pressure regulator.

That's what I'm thinking Dan. Something fuel related anyway. With the smell and the way it turns over, seems like fuel continues to dump after I turn it off.

If you pull the vacuum hose off the FPR and smell it, there should be no smell of gas. If you smell gas the diaphragm is leaking and gas is being sucked right in to the intake manifold.

Ding ding ding, we have a winner!!! Are those expensive?

Depends on the car, but generally it's not an expensive part.