Total engine power loss when car is heat soaked

[big_news_1]

'97 SE with the L36

Fuel pump was replaced with a Delco unit about 3 months ago.

When I drive the car for approximately 30 minutes or more it will suddenly lose almost all engine power and start sputtering. After a minute or so of sputtering it will usually die. If I attempt to restart it will sputter for a few seconds then die again. However if I let the car sit and cool down for an hour or so it will start up and run without problems until it gets heatsoaked again. Got stranded in a few less-than-desirable places a couple times until I figured out I had to limit myself to relatively short trips with a good cooldown period in between.

Not sure if it's related, but sometimes I smell fuel when I make a short run and then shut it down, or when I restart it when it's hot.

Fuel pump or evap issues? Something else electrical? I really have no idea on this one.

EDIT: There are no DTCs or misfires when this occurs.

[hammerheart]

Have you checked all the fuel lines to make sure they're all securely connected? I'd check at the filter and at the fuel rail.

Kind of weird about the post 30-minutes of driving, but another thing you could do is drive it around for ~30 minutes, then check the fuel pressure. Also the fuel pressure regulator. Not sure if it could cause the problem, but it's an easy thing to test.

[J Wikoff]

Crank sensor or ICM/coils?

[1oldman]

When the condition you describe has happened to me it's been either vapor lock or a defective ICM. - BC

[willwren]

Disconnect your FPR after a 5-minute cooldown from a drive. Do you smell fuel in the vacuum line?

Do you have a spare ICM to swap in? I had one that would only fail when hot. I have also seen crank sensors that would fail when hot, and throw no codes. Rule out the easier stuff first!

[RJolly87]

My first thought was a clogged catalytic converter.

[big_news_1]

I guess it would be nice if it was only the ICM. I'll swap one in. Hope it's not the *dang* crank sensor.

I don't smell gas in the FPR. Maybe very, very faint but it seems normal.

I don't think it's the catalytic converter... Aren't most cats fully heated up much faster than 30 minutes?

The symptoms are almost identical to when my fuel pump was failing a few months ago, except with the fuel pump it would happen after only a couple minutes of the engine running. I don't have a fuel pressure tester, but I'll try to do a scan while it's sputtering to see what the STFTs are doing.

[mrsnrobinson]

i am having the same problem. Replaced the ignition control module and the crank position sensor. Hopefully someone can solve this one.