My daily driver '89 Volvo 740 when it gets superhot outside or gets to near half a tank of gas or below
it will sputter around corners and start missing at speed and eventually die out and will not start for a few hours.
I have replaced both the intank and inline fuel pumps, filters, fuel pump relay and fuses but it still acts up.
When its stalled out if you disconnect the fuel line after the regulator there is no gas when you try to start it.

What have I missed?

I had this same problem a few years ago and must have taken it to the mechanic about 6x before they replaced the ignition coil. worked like a dream until yesterday when it started doing the same thing again. my problem also happened after a long day of rain. I'm replacing the coil this afternoon, and I'll let you know if it works or not. hopefully it does, I fully plan on driving it into the ground! :banana:

Mine would do the same thing when it got hot out. Ended up being a power stage going bad. When it got above 80 degrees the unit was unable to cool enough to work properly.

yes do a search on here for ignition amplifier, will prob be loads of me posting about it as everyone seems to have this problem once in they're volvo life. there should be lots of info on it.

Matt

resistor unit

Go get some Thermal transfer cream and apply it to a cleaned up powerstage plate & a cleaned up recieving plate(on the inner fender).
Apply dielectric grease to ALL connections including plug wires & on the ECM.
After that, take a look at the inner distributor~The hall sensor inside the distibutor could be deteriorated due to a leaking distributor shaft seal. OR the wires from the hall sensor could be the same.
When the mucked up hall sensor gets hot, it will shut down the car or make it run bad.
Replace if there's oil inside the distributor. Dont get a new distributor if you can help it. just replace the hall sensor, Rotor, cap & shaft seal.(a whole lot cheaper)
Since a so called "new" distributor is just a rebuilt one anyway.