I'm trying to diagnose a problem I'm experiencing that *seems* to have worsened over time.
My MX-3, at very slight throttle, will accelerate slowly but smoothly all the way to redline without problems...
But at anything over 1/4 throttle the engine will stumble badly at about 2000-2500 RPM. At full throttle, the stumble/hesitation is so severe that the engine will not recover. It just keeps misfiring/stumbing along. The exhaust pulses from the tailpipe on a cold day do not come out smoothly. The problem does not disappear at speed. The problem persists standing still in N and Park, and in D and Reverse. Take off the gas and it will go back to idle cheerfully.
** Here's what I've already done/tested:
New distributor.
New spark plugs, wires, cap, rotor.
New fuel filter.
New air filter.
No CEL or codes thrown from the ECM.
Fuel injector cleaner run through the gas tank.
PCV valve given "blow through" test.
EGR system given "functional check" with vaccuum pump.
MAF tested & is within specification.
Oil, Transmission fluid ok, not burnt, not milky.
Coolant level low.
Apparent hole in downpipe after precat and before catalytic converter.
Low compression in cylinder 2 (105 psi)
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I've been checking every vaccuum line I can find and while I've found and fixed one broken connection, (intake to EGR solenoid) it didn't make any difference.
Has anyone else experienced anything like this, and where would you start looking next?
This poor beautiful car needs to be on the road.
![Dunno :dunno:](./images/smilies/dunno.gif)