Greetings, I am trying to fix a problem with an 86-420SEL with 103,000 miles, only under heavy acceleration it will hesitate, miss and "pop," it only does it after it gets warm. If you accelerate smoothly (normally) it has no problem, it only acts up if you "floor" it. The car has had new spark-plug wires and fuel pumps recently. I have tried a CIS sensor (in intake), EHA, over-voltage protection relay, fuel pump relay, and even a fuel distributor (luckily I have a "donor" car that I can swap parts with) I am now eyeing the dreaded "air flow sensor" just what does that thing do anyway? Is there a "foolproof" way to test it.
Thanks in advance, Phill

Whelp, I guess I will try the airflow sensor this morning I will let ya know how it works out. Got to have the car running right one way or another by this afternoon..... Phill

Hmmmmm..... I have now either replaced or swapped the following parts:
Coil, Plugs & wires, cap, rotor, fuel pumps, OVP relay, fuel pump relay, EHA unit, fuel regulator (on the side of the throttle body), fuel distributor, airflow sensor, TPS (the switch mounted on the lower "flap"), CIS sensor in intake, EZL unit and Green lead. I think tomorrow I will try the distributor... I wonder if my wife would miss the kitchen sink?????
Same symptoms: stumbles on heavy acceleration from a stop (like a stop sign) them runs fine, idles fine and accelerates fine if done slowly or after moving......

I want to apologize to you guru's out there, I know you guys cringe when you hear about this kind of diagnosis, (Donny, Steve) however it is the only technique available to me.

You almost had done lots of things, ...way to go. What about the FUEL FILTER, ...and or the ignition control unit ?Let us know if there's any progress.......

Well, it turned out to be injectors! I have never heard of them acting that way, but, you are never to old to learn! I want to thank you guys for your thoughts on this problem! Hope all your problems are small ones! phill