97 Olds 88 quick cutout when warm, then normal

[earl84]

Long title for a thread, but it's an accurate description. Car is a 1997 Olds 88 with 185,000 miles on it.
Here's what happens. My car will run normally, although the idle is very slightly erratic pretty much all the time. Hardly noticeable unless you are tuned in to it. But that is not my real issue, just background information in case it has any bearing on my real problem.
My real problem is this. When I start my car cold, it runs fine. If I get it up to temperature and park for about 20-40 minutes, it will have a strong cutout, like the engine has stopped running, then will resume running normally. It may do this one to three times, then it will run normally. Occasionally, if I am sitting still, the engine will stop running after a normal startup. If I hold the accelerator down and keep the RPM up a little, it will continue to run. Seems like sometimes I can hear something mechanical clicking under the hood on the passenger side. Something must be getting heat-soaked. If I wait for more than about 45 minutes, it will start and run normally. It is not giving a Check Engine Light or throwing any codes. I did get a CEL and code P0171 (Fuel Trim System Lean Bank 1) the other day, but think it was only related to the vacuum line coming off that goes to my heater/defroster, recirc switch on the dash. Maybe it was related, but I reconnected and the light has not come back. I have also intermittently over the past couple years gotten a P0102 (Mass Air Flow Sensor Circuit Low Frequency), and P1870 (Transmission Component Slipping). Every time I reset them, they go awasy and don't come back for months at a time. Don't know if any of them are related, but throwing them out there.


I have had this issue in the past, but it went away for almost a year. I threw a bunch of parts at it then; new fuel pump, new Ignition Control Module, new coils, new spark plug wires, new fuel regulator, and the problem went away. This time, I have replaced the ICM, and the EGR Valve (due to the clicking noise), and it still does it. I did take it to a mechanic last time I had the issue, and he could not find any odd readings or figure anything else out, hence the shotgun approach of throwing parts at it. Not real advanced mechanic work, I know, but I can replace parts really well, haha.
Over the last 2 years or so, it has had a new MAF sensor, new Crankshaft sensor, new cam sensor, new throttle position sensor, new Intake Air Temp Sensor.

Anyone have any other ideas?

[maxwedge]

unplug the maf, see what happens, if this is a reman, they can fail in pretty short time. Also check fuel pressure just to be sure.

[earl84]

I assume that you mean unplug while it's running, right? Or unplug and then try to start? I will give this a shot later, hopefully today, but it is Sunday and there is football on. Gotta watch my Vikings lose again
Thanks for your help. Will post back results.

[earl84]

Unplugged the MAF, started, ran like crap. Plugged back in and restarted, ran great, so not the MAF Sensor. Any other ideas?

[maxwedge]

Ok, so it starts and stalls when warmed up , then restarts, does it stall when driving?

[earl84]

It will not stall from a cold start until I shut it off or run out of gas. It will only stall when it sits for about 30-45 minutes after being completely warmed up to operating temperature. And then it may stall, like a complete engine shutoff type of stall that lasts only a split second, and then it catches and runs fine without me having to restart it and continues to run. If I am at a stoplight, sometimes it will die, but usually it will catch and continue to run without me having to restart it. It may do this like 2 or 3 times or sometimes not at all, then it will run perfectly until the next time I stop and park for another 30-45 minutes, then it might stall again. After a 45 minute cool-down it will start and run just fine with no stalling at all, just like from a cold start.
It sure seems like something is getting heat soaked, and then once some air is passing over whatever component to cool it, it is fine. I thought that maybe there was a fuel line that got hot and maybe boiled some gas in the line, or some air got in a fuel line somehow. I just don't know.

[maxwedge]

Tough issue, lazy iac, tempermental maf, look for fuel in the press. reg hose.