I pulled my 240 off the road as it was getting hard to drive.
it seems like its running ok, engine has good compression I rebuilt it just 20 years ago ;-) did the head gasket last year all looked nice still,

it idles ok, actually it was runing smoothand exceptionally well.. but now when I accelerate it sometimes feels like I'm putting my foot into the gas and the car doesn't know, after a moment it seems to correct then it goes, If I floor it it has power..

I'm planing to check the throttle closed switch because I'm wondering if maybe its not opening the switch , maybe hen the ECU is seeing it closed throttle, but after I floor it maybe, after a few seconds it realizes its running way lean and then corrects via the air mass meter and 02 sensor telling the ECU to give more fuel..

a few seconds is a lot when I'm making a left turn and the car suddenly won't clear an intersection , so its off the road, not a huge rush but I do want o fix it.

I thought I could try another air mass meter, or maybe inject smoke into the intake, some use a vape pen and a little air pump to force in "smoke " from a vape pen in, then look for any intake hose leaks, I could try that, Ive been meaning to make such a rig up.

bad ECU maybe?

I tried to read the codes.. I could not get the thing to blink at all so it might have a fault code but I don't seem able to retrieve it.

Ive heard that the mass meter can fail because the airbox has a valve that can fail and cause it to constantly suck hot air from the hose that runs near the exhaust manifold, but Ive noticed its a bit disconnected.

I tried the spray cleaners for the air mass meter, then got my glasses and actually read the can and it says not for use on heated air mass meters, I think the 240 one is heated but that cleaning wasn't too recent and it was running perfectly before all this..

the problem seemed to happen just once in a while but got more frequent.

any thoughts on how to troubleshoot this are appreciated.