Random RPM Drop
 

I'm having a random RPM drop while driving my 97 Monte Carlo Z34. Dealer told me it was a timing chain issue but do not think so. Car has about 115K miles. 2nd opinion told me it was a fuel pump. Long story short I changed plugs, wires, intake gasket, manifold gasket, coils and fuel filter. Found 20psi fuel pressure once switch is turned. 38-40psi fuel pressure while running.

Car ran perfect for about 1 month then started rpm drops again. I'm thinking it is transmission related. Possibly a sticking shift solenoid? Anyone else experienced this? RPM drops are close to or around shifts also at takeoff. Cruise control works fine no issues.

If the car starts to buck and drop RPM, I can press the pedal and power through without further hesitation. Can smoke the tires with no problem. Noticed if I manual shift to L1 then L2 there are no issues. Only in D and OD. Very random and driving me crazy. Thinking of changing trans fluid but it has never been changed before and I have heard all of the stories. At this point, not sure I have to loose anything.

Help?:confused:

Just an update. I changed the transmission filter and fluid. Hoping to see the accumulator pipe loose however it was fine. Back to square 1. Also tried unhooking the MAF sensor to see if it would run better thinking it may be faulty. Stutter with and without the MAF connected. Anybody have any more suggestions. Plan to test Cat and change ICM next.